Colon Health Advanced Formula [Discontinued] by Vitaganic Inc

EFFECTIVE

• Dyspepsia. Oral calcium carbonate is approved by the US Food and Drug Administration (FDA) as an antacid. Details: Taking calcium carbonate orally as an antacid is effective for treating dyspepsia (1843). Calcium carbonate has FDA approval as an antacid.
• Hyperkalemia. Intravenous calcium gluconate is approved by the US Food and Drug Administration (FDA) for preventing hyperkalemia-induced cardiac abnormalities. Details: Administering calcium gluconate intravenously can reverse electrocardiographic changes and arrhythmias induced by hyperkalemia (12946). Intravenous calcium gluconate is FDA-approved for preventing hyperkalemia-induced cardiac abnormalities.
• Hypocalcemia. Oral calcium treats and prevents hypocalcemia. Intravenous calcium is used to treat severe hypocalcemia. Details: Taking calcium orally is effective for treating and preventing hypocalcemia. Intravenous calcium gluconate, acetate, gluceptate, or chloride is effective for severe hypocalcemia or hypocalcemic tetany (12928).
• Kidney failure. Oral calcium carbonate or calcium acetate is used as a phosphate binder during kidney failure. Details: Taking calcium carbonate or calcium acetate orally is effective as a phosphate binder. Calcium acetate (PhosLo) appears to control hyperphosphatemia better than sevelamer (Renagel) (12943,12944,38990). Calcium citrate is not recommended for this purpose because it increases aluminum absorption and does not bind phosphate as efficiently as calcium acetate or calcium carbonate (21631). Some clinical research also shows that taking calcium orally reduces blood pressure in patients with kidney failure (975).

LIKELY EFFECTIVE

• Corticosteroid-induced osteoporosis. Oral calcium in combination with vitamin D prevents bone density loss that occurs during long-term treatment with corticosteroids. Details: Taking calcium in combination with vitamin D as adjunctive therapy seems to be effective for reducing bone mineral density loss in people using corticosteroids long-term (982,1046,1830,1831,1832,4462,4463,4464,4465,4466)(4467,12945,38493). One specific product used in clinical research is Oscal (Marion Merrel Dow Inc.), which contains elemental calcium 500 mg per tablet plus vitamin D 125 IU per tablet (982). Another product used is Oscal 250 + D (SmithKline Beecham Healthcare), which contains elemental calcium 250 mg and vitamin D 125 IU per tablet (1046).
• Hyperparathyroidism. Oral calcium reduces parathyroid hormone levels in patients with secondary hyperparathyroidism due to kidney failure. Details: Taking calcium orally reduces parathyroid hormone levels in patients with kidney failure and secondary hyperparathyroidism (1827,1828,1829,39174,39425). In elderly women, the combination of calcium and vitamin D reverses secondary hyperparathyroidism and reduces hip fracture risk (8818). Also, population research suggests increased calcium intake from the diet and supplements reduces the risk of primary hyperparathyroidism in women. Supplemental intakes of at least 500 mg/day and dietary intakes of approximately 1100 mg/day are considered to be protective (91353).
• Osteoporosis. Adequate calcium intake, from the diet and/or supplements, is recommended for the prevention and treatment of osteoporosis. Details: The Bone Health and Osteoporosis Foundation (BHOF) recommends ensuring adequate calcium intake in line with the recommended dietary allowance (RDA) by age, along with adequate vitamin D intake, for the prevention and treatment of osteoporosis in adults over 50 years of age. Supplementation can be used to augment dietary intake when adequate dietary intake is not feasible (109425). In the US and Canada, foods containing at least 200 mg calcium with less phosphorous content than calcium can be labelled with a health claim regarding the relationship between adequate calcium intake and a reduced risk for osteoporosis (11940,102148). However, calcium supplementation is not recommended specifically for the primary prevention of osteoporosis. The US Preventive Task Force (USPSTF) states that the current evidence is insufficient to assess the balance of benefits and harms of vitamin D and calcium supplementation, alone or in combination, for the primary prevention of fractures in community dwelling adults without osteoporosis (95695). Also, calcium supplements do not seem to be effective for preventing loss of bone mineral density (BMD) during lactation (988), in patients who have had bone marrow transplantation (1817), or in patients who have had renal transplantation (4823,38736,38871). Maximal bone growth occurs in the teenage years, and then BMD in females remains relatively constant until age 30-40. After age 40, bone loss typically occurs at rates of 0.5% to 1% per year. In males, this occurs several decades later. Bone loss is more pronounced if dietary calcium intake is below the RDA, which is the case for many Americans (2571,2578). One meta-analysis of randomized controlled trials in healthy children 7-14 years old shows that fortifying food with calcium 250-1000 mg daily for up to 24 months modestly improves femoral neck BMD, but not hip or spine BMD. However, the included trials did not supplement vitamin D (107232). During the 5 years immediately after menopause, calcium supplementation has very little effect on bone loss (2569,2570,2575,2576). The rapid loss of estrogen causes a high bone resorption rate, which increases serum calcium levels and therefore decreases intestinal absorption of calcium (2570). After this period, the typical rate of bone loss is 2% per year (2572,2576). Taking calcium 1000-1600 mg daily as carbonate, citrate, lactate gluconate, or citrate malate salt decreases this rate by 0.25% to 1% annually (977,979,981,2569,2571,2572,2575,2576,2578,6850)(38978,38980,39064). The greatest reductions (1% or more) are seen in the first 1-2 years of supplementation when bone remodeling foci can be filled (2569,2576). After this period, the differences in rate of loss between supplemented and non-supplemented females are closer to 0.25% per year (2569,2577). A meta-analysis of clinical evidence suggests that there is no additional benefit after 4 years (38980). Small clinical studies have found that continuous calcium supplementation at an average daily dose of 1050 mg, started after menopause and continued for 1.5-4 years, may reduce fracture rates by 26% when compared with no calcium supplementation. The largest of these studies was conducted in nursing home residents who also received daily vitamin D; the benefits of calcium, specifically, are unclear (39386). Some research also suggests that calcium and vitamin D improves primary prevention of osteoporotic fractures in some older individuals with osteoporosis, particularly the elderly and those who are no longer community dwelling (12930,38875,38849,39026,109471). However, not all research is positive. One large clinical trial in elderly adults with a low-trauma fracture show that taking calcium 1000 mg daily with or without vitamin D 800 IU daily for 2-7 years does not reduce the risk of a second fracture when compared with placebo (13073). Another clinical study shows that taking calcium 1000 mg daily plus vitamin D 800 IU daily does not prevent a second fracture in elderly patients, or prevent a first fracture in elderly patients with other risk factors such as low body weight (less than 58 kg, 127.6 pounds), smoking, family history of hip fracture, or fair or poor self-reported health (12929). Also, some exploratory research suggests that supplements may need to be continued indefinitely; in adults over 68 years of age, any effects of 2 years of calcium supplements on BMD appear to be lost within 2 years after discontinuing supplements (6853). Calcium has additive effects when used with other agents such as vitamin D, estrogens, or calcitonin. Whereas calcium alone generally reduces or prevents loss of BMD, combination with other agents can produce small increases in BMD ranging from 0.3% to 3.3% depending on the combination and dosages used (978,980,1836,2570,2571,2572,2576). However, one meta-analysis in healthy adults shows that fortifying foods with calcium 250-1000 mg daily, in conjunction with vitamin D supplementation, for up to 24 months does not improve BMD when compared with control (107232). The full potential of osteoporosis treatments cannot be realized without adequate calcium intake (2569,2570,2571,2572). Advise patients taking agents such as estrogens, calcitonin, bisphosphonates, or raloxifene (Evista) to ensure that their daily calcium intake meets the RDA. Use supplements if necessary. The usefulness of calcium in preventing osteoporosis in males is not as well-studied. Some observational research has found that calcium 870 mg daily is not associated with changes in BMD and bone loss in males (97201). However, clinical evidence suggests that taking calcium 1000 mg daily for 2 years might improve trabecular or cortical bone mass by 2% to 4% (980,8827,8873). Dietary supplementation with calcium and vitamin D seems to moderately reduce bone loss measured in the femoral neck, spine, and total body, and seems to reduce the incidence of nonvertebral fractures in older patients with osteopenia or low BMD (980).
• Premenstrual syndrome (PMS). Adequate calcium intake seems to prevent symptoms of PMS. Details: There seems to be a link between low dietary calcium intake and symptoms of PMS (2004,6847,39007). Taking calcium 1000-1336 mg daily seems to significantly reduce depressed mood, water retention, and pain, especially if daily calcium intake is inadequate (1822,1823,1824,2004,95821). Calcium carbonate 1200 mg daily seems to decrease PMS symptom scores by about 18% when compared with placebo (1822). Increasing dietary calcium intake is also associated with a decreased risk of developing PMS. Consuming an average of 1283 mg of calcium per day from foods is associated with about a 30% lower risk of developing PMS compared with consuming an average of 529 mg daily (13094); however, taking calcium supplements does not appear to be associated with the risk of developing PMS.

POSSIBLY EFFECTIVE

• Colorectal cancer. Oral calcium seems to be beneficial for preventing colorectal cancer, especially in those with adequate vitamin D levels and normal body mass index (BMI). Details: Population studies have found that increased intake of dietary or supplemental calcium is associated with a reduced risk of colorectal cancer and colorectal adenomas (1047,8820,12120,38951,98898,98899). Clinical trials and meta-analyses of clinical research also show that taking calcium supplements 1.2-2 grams daily for up to 4 years can reduce the risk of colorectal adenoma recurrence by up to 29% (970,12118,12950,15267,34596,38718,39042,95817). However, not all research has been positive. Some meta-analyses of clinical research or observational studies suggest that taking calcium does not reduce the risk of familial adenomatous polyposis or colorectal cancer (34596,39042,39349). Other contradictory research suggests that postmenopausal females who take calcium 1000 mg daily plus vitamin D 400 IU daily do not have a reduced risk of developing colorectal cancer (14290); however, this finding may not be reliable due to the high baseline intake of calcium in study participants. The reason for these conflicting findings is not entirely clear. Vitamin D might be an important factor. People with lower than average vitamin D levels do not seem to get any benefit from calcium supplements (12118). Also, one meta-analysis of previous trials suggests that taking calcium 1200 mg daily reduces the risk of colorectal adenomas in people with a normal BMI, but not in those who are overweight or obese (99715). Despite this conflicting evidence, the US Food and Drug Administration (FDA) approved a qualified health claim in 2005 stating that calcium supplements may reduce the risk of colorectal cancer and colorectal adenomas. However, the FDA has determined that there is little scientific evidence to support this claim (102366).
• Fetal bone mineralization. If calcium intakes are low during pregnancy, oral calcium seems to be beneficial for increasing fetal bone density. Details: With low dietary calcium intake (less than 562 mg elemental calcium daily) during pregnancy, calcium supplementation increases fetal bone mineralization and density. However, calcium supplementation does not offer any additional benefit if calcium intakes are adequate (3263,3264).
• Hypertension. Oral calcium seems to reduce blood pressure by a small amount in adults with or without hypertension. However, it is unclear if this reduction is clinically significant. Details: Many clinical trials and observational studies, including a meta-analysis of 18 high-quality clinical trials, show that intake of calcium supplements or dietary calcium modestly reduces systolic blood pressure in patients with or without hypertension, usually around 1-2 mmHg. Calcium seems to be more effective for certain subpopulations of patients, such as those who are salt-sensitive or have low baseline dietary calcium intake (945,972,974,976,984,1818,1819,1820,1821,6852)(13138,14406,38803,39063,39094,39221,113920,113925). However, a large-scale clinical trial in postmenopausal females shows that taking vitamin D (cholecalciferol) 400 IU daily in combination with elemental calcium 1000 mg daily does not lower blood pressure or reduce the risk of developing hypertension (16714). Additionally, a meta-analysis of 8 clinical trials shows that taking calcium in combination with vitamin D for up to 7 years has no effect on blood pressure (98861). The validity of this finding is limited by the poor methodological quality of the included studies. Some observational research suggests that calcium can reduce the risk for hypertension. Population research in females aged 45 years and older suggests that higher intake of calcium from both diet and supplemental sources is linked to a lower risk of developing hypertension when compared to lower calcium intake (14265). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim stating that calcium supplements may reduce the risk of hypertension. However, the FDA has concluded that this claim is based on supporting, rather than conclusive, evidence (102367). Research evaluating the effect of calcium supplementation during pregnancy on the child's blood pressure has yielded conflicting findings. A systematic review of 2 clinical studies and 3 observational studies found that calcium intake during pregnancy is associated with a 1-2 mmHg reduction in the systolic blood pressure of the offspring between the ages of 1-7 years (38852). However, a separate meta-analysis of 3 clinical studies shows that calcium intake during pregnancy does not reduce systolic or diastolic blood pressure in the offspring (113923).
• Osteomalacia. Oral calcium seems to reverse osteomalacia caused by very low calcium intakes. Details: Osteomalacia is commonly caused by vitamin D deficiency; however, very low calcium intake can also lead to osteomalacia in children and adults. Calcium supplementation can reverse osteomalacia caused by calcium deficiency. Along with appropriate vitamin D supplementation, individuals at risk of osteomalacia need sufficient calcium intake (94819).
• Pre-eclampsia. Oral calcium seems to reduce the risk of pre-eclampsia, especially in high-risk individuals and those with low baseline dietary calcium intake. Details: Although there is some conflicting evidence (971,38756), most clinical research shows that taking calcium orally 1-2 grams daily reduces the risk of pre-eclampsia (973,1833,8828,39043,39319,39426,97348,113919). A large clinical trial of 11,000 pregnant individuals in India and Tanzania shows that supplementation with 500 mg daily is similarly effective to 1500 mg daily (113908). Multiple meta-analyses which include 16-30 clinical studies have found that varying doses of calcium supplementation reduce the relative risk of pre-eclampsia by 46% to 51% when compared with placebo (97348,113909,113919). One of these meta-analyses found that for every 19 females treated with calcium, one episode of pre-eclampsia would be avoided (97348). Additionally, one of these meta-analyses found that calcium reduces the relative risk of pre-eclampsia by 51%, regardless of whether it is taken at a dose above or below 1000 mg daily (113919). Some research suggests that calcium supplementation may have a greater effect in individuals at high risk of pre-eclampsia or with low baseline dietary calcium intake, and when taken at greater than or equal to 20 weeks of gestation (15029,38497,97348,99714,113919). However, another meta-analysis of 30 clinical studies found a similar benefit of calcium in both high- and low-risk individuals (113919). A separate meta-analysis of 6 clinical studies conducted in China evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy. This combination was associated with an 80% lower relative risk of pre-eclampsia and an 83% lower relative risk of pre-eclampsia with gestational hypertension when compared with routine care (113913). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding the use of calcium supplements to reduce the risk of pregnancy-induced hypertension and pre-eclampsia. However, due to the limited and conflicting research available at that time, the FDA stated that this outcome was highly unlikely (102366). Since then, large, high-quality clinical research has supported this finding. In fact, in 2016 the World Health Organization (WHO) released a recommendation to prescribe oral calcium 1.5-2 grams daily during pregnancies at high risk of pre-eclampsia if dietary calcium intakes are low (97347).
• Pregnancy-induced hypertension. Oral calcium may reduce the risk of pregnancy-induced hypertension. Details: A meta-analysis of 17 clinical studies shows that calcium supplementation during pregnancy may reduce the relative risk of pregnancy-induced hypertension by 30% when compared with control (113909). A separate meta-analysis of 6 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of pregnancy-induced hypertension by 85% when compared with routine care (113913).
• Rickets. Oral calcium seems to reverse rickets caused by very low calcium intakes. Details: Rickets is commonly caused be vitamin D deficiency; however, very low calcium intake can also lead to rickets. Calcium supplementation can reverse rickets caused by calcium deficiency (94819). A small clinical study in children with nutritional rickets shows that taking calcium 500-2000 mg daily for 24 weeks improves radiographically measured rickets caused by calcium deficiency. Rickets seems to improve more rapidly with calcium 1000 mg compared to calcium 500 mg. However, increasing the calcium dose to 2000 mg daily is not more beneficial than calcium 1000 mg daily (98904).
• Tooth retention. Oral calcium with vitamin D seems to help with tooth retention in the elderly population. Details: A clinical trial in the elderly population shows that taking calcium citrate malate 500 mg daily along with vitamin D3 (cholecalciferol) 700 IU daily orally for 3 years reduces the risk of tooth loss by about 52% when compared with placebo (8816).

POSSIBLY INEFFECTIVE

• Breast cancer. Oral calcium, via supplementation or as part of the diet, does not seem to be beneficial for breast cancer prevention. Details: Although some studies disagree (15631,39041,95811,107237,113917), most population research suggests that increased calcium intake is not associated with overall breast cancer risk (15631,16715,98895,107236,107237,113917). However, one meta-analysis of observational studies shows that although higher total calcium intake is not associated with breast cancer risk, higher dietary calcium intake, specifically, may be associated with a slightly reduced risk (113917). Also, some analyses suggest that calcium intake may be associated with the risk for certain breast cancer sub-types. Some subgroup analyses suggest that calcium intake may reduce the risk of breast cancer in postmenopausal, but not pre-menopausal, adults (15631,107237) and that dietary calcium intake may reduce estrogen receptor(ER)-negative breast cancer, but not ER-positive breast cancer (107236). However, most research has not evaluated the effects of calcium supplementation or intake on breast cancer subtypes. The best evidence to date, from a large scale clinical trial (Women's Health Initiative), shows that taking vitamin D (cholecalciferol) 400 IU daily plus calcium 1000 mg daily for 7 years after menopause does not reduce the risk of developing invasive breast cancer at the end of the study and 5 years after the end of the intervention (16715,98895).
• Fractures. Although oral calcium prevents fractures in osteoporosis, most evidence shows that calcium does NOT prevent factures in people who do not have osteoporosis. See Osteoporosis discussion for more information on the use of calcium for this purpose. Details: Robust meta-analyses of mostly large, high-quality clinical studies show that calcium supplementation 500-1600 mg daily for 0.5-7 years with or without vitamin D does not reduce total fractures, hip fractures, vertebral fractures, or non-vertebral fractures in older adults without osteoporosis (95822,112486). A large-scale study in postmenopausal females aged 50-79 years who were enrolled in the Women's Health Initiative (WHI) suggests that calcium 1000 mg plus vitamin D 400 IU daily for 7 years only modestly improves bone mineral density (BMD) and does not significantly reduce fracture risk. This lack of effect may have been due to low adherence to the treatment regimen. In those who were 80% adherent, the combination of calcium plus vitamin D reduced the risk of hip fracture by about 29% (14282). Also, some clinical research shows that taking calcium carbonate 1000 mg and vitamin D 400 IU for 5 years does not attenuate loss of height after menopause when compared with placebo (95810). Additional meta-analyses of clinical and observational evidence suggest that calcium supplementation is not associated with a reduced risk of vertebral or nonvertebral fractures, such as hip fractures (38589,38888,98895). Some other research has suggested that calcium in combination with vitamin D reduces fracture risk in older patients without osteoporosis (980,1836,8818,12930,12933,12952,38849,102145,107235); however, this research is confounded by a number of variables, including the presence of hormonal therapy and differing levels of fracture risk at baseline (1836,8818,95822). Conflicting findings on this topic might also be due to genetic differences in patient populations. A population analysis of the WHI study found that, in older females with the lowest genetic susceptibility to low BMD, taking calcium with vitamin D is associated with a reduction in fracture risk. However, in females with a higher genetic susceptibility to low BMD, there is no association between supplementation and fracture risk. This might be because individuals with a lower susceptibility to low BMD are also more responsive to calcium and vitamin D supplementation (97357). As of April 2018, the U.S. Preventative Services Task Force (USPSTF) concludes that there is insufficient evidence to determine whether supplementing with vitamin D >400 IU daily along with calcium >1000 mg daily is safe and effective for preventing fractures in community dwelling adults without vitamin D deficiency, osteoporosis, or a history of fracture. USPSTF recommends against supplementing with calcium 1000 mg daily or less along with vitamin D 400 IU daily or less for preventing primary fractures in community-dwelling postmenopausal females (95695).
• Obesity. Oral calcium does not seem to improve weight loss in adults or children with overweight or obesity. Details: Observational research has found that adults and children with low calcium intake are more likely to gain weight, have a higher body mass index (BMI), and be overweight or obese when compared to people with high calcium intake (12124,12125,12126,12127,14265). Additional observational research has found that increasing calcium intake is associated with weight loss in females; the results in males have been conflicting (12127,15602,15603). Despite these findings from observational research and a few small clinical studies (12128,15397,14438,98905,113918), most clinical research has found that increased calcium intake does not increase weight loss (12052,13138,15396,15399,38985,39004,97356). A meta-analysis of 20 clinical studies shows that daily dietary and supplemental calcium intake that meets the dietary reference intake (DRI) of 1000 mg or more daily does not increase weight loss in overweight individuals or patients with obesity when compared with intake below the DRI (95813). An older meta-analysis of 13 clinical trials also shows that increased dietary and supplemental calcium intake does not increase weight loss (15605).
• Overall mortality. Oral calcium does not seem to reduce overall mortality. Details: While some population research has found that calcium taken in combination with vitamin D in older females is associated with a lower risk of death (97353), most evidence shows that calcium, with or without vitamin D, has no effect on all-cause mortality (93533,97308,113584).

INEFFECTIVE

• Cardiovascular disease (CVD). Oral calcium does not reduce the risk of developing CVD and may actually increase risk in some patients. Details: Clinical research shows that calcium does not decrease CVD risk. Several separate meta-analyses of clinical and population research involving over 50,000 patients show that taking calcium 600-1200 mg daily for up to 7 years does not reduce the risk of CVD-related outcomes, including stroke and myocardial infarction, cardiovascular death, or overall mortality (39018,91350,92994,93533,97308,98902,107231,107233). No association was found between total dietary or supplemental calcium intake with or without vitamin D and the risk of CVD or mortality (91350,93533,97308). In fact, some population and clinical research has found that when calcium is used alone or with vitamin D, there is an INCREASED risk of CVD and coronary heart disease (38077,107233). However, other clinical research disagrees (93533). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of CVD and coronary heart disease by 1.1-1.2 times when compared with control. However, the majority of the included research evaluated postmenopausal females and it is unclear if this finding is applicable to other populations (107233).
• Chemotherapy-induced peripheral neuropathy. Intravenous calcium does not prevent nerve pain in patients given oxaliplatin. Oral calcium has not been evaluated for this purpose. Details: While pooled analyses of cohort studies and randomized controlled trials suggest that calcium and magnesium infusion decreases the incidence of oxaliplatin-induced neurotoxicity, a meta-analysis of only randomized controlled trials shows that the infusion has no effect in preventing neurotoxicity (90028,90029,90031). Additionally, clinical trials show that administering calcium gluconate 1 gram with magnesium sulfate 1 gram intravenously immediately before, or before and after, the administration of a single oxaliplatin cycle (90005), or over the entire 6-cycle course of oxaliplatin, does not improve symptoms of neurotoxicity when compared with placebo (96474).
• Myocardial infarction (MI). Oral calcium does not prevent MI. When taken in the absence of vitamin D, oral calcium may increase the risk of MI. Details: Population research has found that increased dietary intake of calcium is associated with a decreased risk of MI (91350). However, a 2010 meta-analysis of clinical research shows that taking calcium at a dose of at least 500 mg daily is associated with an approximate 30% INCREASE in the risk of MI in patients over the age of 40. According to this analysis, one additional case of MI will occur for every 69 patients that take calcium for 5 years (17482). A more recent meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of MI by 1.2 times when compared with control. However, the majority of the included research studied postmenopausal females and it is unclear if this finding is applicable to other populations (107233) In contrast, other meta-analyses of clinical research have shown that taking calcium for up to 7 years is NOT associated with an increased risk of MI, including a meta-analysis that only included postmenopausal females (93533,107231). Reasons for these discrepancies are not entirely clear. It may relate to whether calcium is taken as monotherapy or in combination with vitamin D. When taken with vitamin D, which is commonly recommended, calcium supplementation does not appear to be associated with an increased risk of MI in postmenopausal females (93533). Also, the association between calcium supplementation and MI risk may be influenced by the amount of calcium consumed as part of the diet. Supplementation with calcium may be associated with an increased risk of MI in people with dietary calcium intake above 805 mg daily, but not in those with dietary calcium intake below 805 mg daily (17482)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. It is unclear if oral calcium is beneficial for alcohol use disorder. Details: Preliminary clinical research shows that taking calcium carbonate 800 mg and vitamin D 200 IU orally daily for 14 days modestly reduces alcohol craving scores and withdrawal scores when compared with placebo in adults with alcohol dependence that are undergoing withdrawal. Taking calcium carbonate did not reduce the need for diazepam; however, the study may have been inadequately powered to detect a difference between groups (107234).
• Atherosclerosis. It is unclear if oral calcium is beneficial for atherosclerosis. Details: A population study has found that taking calcium 1.2 grams daily for 3 years has no effect on carotid intima thickness or carotid atherosclerosis incidence. A total calcium intake (dietary and supplemental) of at least 1794 mg daily in older females may be associated with a decreased risk of carotid atherosclerosis when compared with a total calcium intake below 1010 mg daily (97351).
• Autism spectrum disorder. It is unclear if oral calcium during pregnancy is beneficial for reducing the odds of autism spectrum disorder in the offspring. Details: A small observational study found that calcium supplementation during pregnancy is associated with a 52% reduced odds of an autism spectrum disorder in the offspring (98900).
• Brain tumor. It is unclear if dietary calcium intake is associated with risk of brain tumor. Details: A meta-analysis of 4 case-control studies has found that higher dietary calcium intake is associated with a lower odds of brain tumor when compared with lower dietary intake (113922). The validity of this finding is limited by the exploratory nature of the included studies, which analyzed all dietary ingredients for any potential associations.
• Cancer. Oral calcium alone does not seem to prevent cancer. It is unclear if oral calcium with vitamin D is beneficial for preventing cancer. Details: Taking calcium alone does not seem to significantly reduce the risk of cancer (12118,15629). The role of calcium in cancer prevention when taken along with vitamin D is controversial, as conflicting results exist. One clinical trial shows that healthy postmenopausal females who take supplemental calcium 1400-1500 mg daily plus vitamin D3 (cholecalciferol) 1100 IU daily have a 60% lower relative risk for developing cancer of any type. Approximately 25 postmenopausal females would need to take this combination for 4 years to prevent one occurrence of cancer (15629). However, a more recent clinical study shows that healthy postmenopausal females who take supplemental calcium 1500 mg daily plus vitamin D3 (cholecalciferol) 2000 IU daily do not have a reduced risk of cancer at 4 years (93943). Reasons for the disparate results are not entirely clear. The discrepancies do not appear to be related to baseline vitamin D levels or different study populations. It is possible that, given the 10-year time lapse between the two publications, the discrepancies result from differences in cancer detection capability. Also, since cancer risk was a secondary outcome measure in the earlier study and a primary outcome measure in the more recent study, it is possible that the discrepancies result from differences in statistical methodologies. The effect of vitamin D and calcium on cancer risk in males and younger patients is not known. There is also interest in using calcium for reducing the risk of hematological malignancies. An analysis of the Women's Health Initiative study shows that taking calcium 1000 mg daily in combination with vitamin D3 400 IU for up to 10 years is associated with a 20% reduction in the risk of hematologic malignancies when compared with placebo. However, no effect on hematologic malignancy related mortality was seen (97354).
• Depression. It is unclear if oral calcium is beneficial for depression prevention. Details: Population research has found no association between a higher dietary intake of calcium and the risk of depression when compared with a lower dietary intake of calcium (96480).
• Diabetes. It is unclear if dietary calcium intake is associated with type 2 diabetes risk. Details: Some population research has found that a higher intake of calcium from the diet or supplements, alone or in combination with vitamin D, is associated with a lower risk of developing type 2 diabetes when compared with lower calcium intake (14265,16713,96473,113929). One meta-analysis of cohort and cross-sectional studies found that the highest level of dietary calcium intake is associated with an 18% relative reduction in risk of type 2 diabetes when compared with the lowest level of intake. A dose-response analysis suggests that each 300, 600, and 1000 mg per day increase in dietary calcium intake is associated with a 7%, 14%, and 23% reduced risk of type 2 diabetes, respectively (113929). However, population research is often limited by confounding variables. For example, one analysis suggests that any beneficial effect might be influenced by concomitant magnesium intake (96473,113929), while another suggests that any benefit from increased intake may be more pronounced in females, adults aged 50 years or older, and Asian populations (113929). Furthermore, other population research has found that serum calcium levels higher than 9.6 mg/dL are associated with greater risk of developing diabetes in Chinese adults with osteoporosis (95815).
• Dyslipidemia. It is unclear if oral calcium is beneficial for dyslipidemia. Details: One clinical study in adults with mild to moderate hypercholesterolemia shows that adding calcium carbonate 400 mg three times daily to a low-fat diet (American Heart Association Step 1) for 6 weeks reduces low-density lipoprotein (LDL) cholesterol levels by 4% and increases high-density lipoprotein (HDL) cholesterol levels by 4% when compared with the low-fat diet and placebo (2557). In contrast, a clinical study in females with dyslipidemia shows that taking calcium 800 mg daily for 2 years INCREASES total cholesterol levels and carotid intima-media thickness in postmenopausal, but not premenopausal, females when compared with placebo (97350). Calcium supplementation has also been evaluated in combination with vitamin D. A meta-analysis of randomized controlled trials including adults with normolipidemia and dyslipidemia shows that taking calcium 500-2000 mg daily and vitamin D 200-7142 IU daily modestly improves HDL cholesterol and triglyceride levels, but not LDL cholesterol levels, when compared with placebo. Subgroup analyses suggest that calcium and vitamin D supplementation is most beneficial in patients with dyslipidemia at baseline (107227). The relationship between dietary calcium intake and serum lipid levels has also been evaluated in observational research. A meta-analysis of 7-11 observational studies found that dietary calcium intake is not associated with total cholesterol levels, although small differences in individual lipid parameters were identified. Additionally, a meta-analysis of 4-9 observational studies suggests that calcium intake is not associated with the risk of developing hypertriglyceridemia, hypercholesterolemia, or low HDL. A subgroup analysis found that higher calcium intake may be associated with lower triglyceride levels in Asian populations (113927). Overall, these findings are limited by significant heterogeneity and the cross-sectional nature of the included studies.
• Dysmenorrhea. It is unclear if oral calcium is beneficial for reducing pain associated with dysmenorrhea. Details: Clinical research shows that taking calcium carbonate 1000 mg with vitamin D 5000 IU daily for three menstrual cycles does not reduce pain when compared with placebo in patients with primary dysmenorrhea (95821). However, calcium carbonate 1000 mg taken alone seems to reduce pain when compared with placebo.
• Endometrial cancer. It is unclear if oral calcium is beneficial for endometrial cancer prevention. Details: A meta-analysis of population research suggests that calcium supplements may reduce the risk of endometrial cancer, but dietary calcium does not seem to have any effect (38893).
• Exercise-induced muscle damage. It is unclear if oral calcium is beneficial for reducing exercise-induced muscle damage. Details: A very small clinical study in resistance-trained adults shows that taking calcium carbonate 500 mg 4 times daily for 3 weeks does not attenuate exercise-induced muscle damage from bench presses when compared with placebo (113933). This study may have been inadequately powered to detect a difference between groups.
• Fall prevention. It is unclear if oral calcium with vitamin D is beneficial for preventing falls. Details: Research suggests that calcium in combination with vitamin D, but not calcium alone, might prevent falls by decreasing body sway and normalizing systolic blood pressure (6362,11939,39038). Some experts think the combination of calcium and vitamin D may be important (11916). Preliminary clinical research in adults residing in a health care facility shows that taking vitamin D supplements while increasing dietary calcium and protein for 2 years reduces falls by 11% when compared with standard diets. Intervention diets were supplemented with milk, yogurt, and cheese to provide calcium 1142 mg and protein 69 grams daily (107235). There might also be different effects in females compared to males. In one study, females aged 65 years or older who took vitamin D 700 IU plus calcium citrate 500 mg daily over a 3-year period had a 46% lower risk of falling. However, this combination did not decrease falls in males (14291).
• Fluorosis. Oral calcium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Taking calcium orally, in combination with ascorbic acid (vitamin C) and vitamin D, seems to be effective for reducing excessive fluoride levels in children and improving symptoms of fluorosis in children aged 6-12 years (990).
• Heart failure. It is unclear if oral calcium in combination with vitamin D is beneficial for preventing heart failure. Details: Based on a secondary analysis of a large-scale clinical trial (Women's Health Initiative), taking calcium 1000 mg with vitamin D 400 IU daily does not reduce the risk of heart failure in the overall population or in individuals at high risk. However, in a subgroup of postmenopausal females without risk factors for heart failure, calcium and vitamin D supplementation might reduce the risk of developing heart failure by about 37% (97307).
• Lead toxicity. It is unclear if oral calcium is beneficial for reducing blood levels of lead. Details: Lead is mobilized along with calcium from bone during pregnancy and lactation, resulting in increased serum concentrations of lead. One clinical study suggests that calcium supplementation does not significantly decrease these elevated lead concentrations (1586). However, another clinical study suggests that taking calcium reduces blood lead levels by 11% when compared with placebo, with greatest effects observed in those with high baseline levels of lead (38957).
• Lyme disease. Although there is interest in using oral calcium for Lyme disease, there is insufficient reliable information about the clinical effects of calcium for this condition.
• Metabolic syndrome. It is unclear if oral calcium alone or with vitamin D is beneficial for metabolic syndrome prevention. Details: Population research has found that a higher intake of calcium from diet and supplements alone, or in combination with vitamin D, is associated with a lower risk of developing metabolic syndrome when compared with lower calcium intake (14265,16713).
• Nephrotic syndrome. It is unclear if oral calcium with vitamin D is beneficial for preventing nephrotic syndrome. Details: Clinical research shows that taking calcium 500-1000 mg daily for 3 months in combination with vitamin D3 60,000 IU daily or weekly for 4 weeks has no effect on bone mineral density or the risk of relapse in children with steroid-sensitive nephrotic syndrome (97355).
• Nonmelanoma skin cancer. It is unclear if oral calcium is beneficial for preventing keratinocyte carcinomas. Details: In middle aged and older adults recently diagnosed with a colorectal adenoma, clinical research shows that taking calcium 1200 mg daily as calcium carbonate for 3-5 years does not reduce the incidence of keratinocyte cancer when compared with placebo over a median of 8 years. A sub-group analysis shows that taking calcium alone or with vitamin D3 1000 IU daily reduced the risk of invasive cutaneous squamous cell carcinoma by a moderate amount, but had no effect on the risk of basal cell carcinoma (104622).
• Oral mucositis. When used in combination with fluoride treatments, a calcium phosphate mouth rinse seems to prevent and reduce mucositis-related pain in patients undergoing hematopoietic stem cell transplantation (HSCT). Details: A small clinical study in patients undergoing HSCT shows that using a particular mouth rinse (Caphosol, EUSA Pharma) containing calcium phosphate, in combination with fluoride treatments, reduces days of mucositis, the duration of pain, and the dose and days of morphine used when compared with placebo and fluoride treatment (38611).
• Ovarian cancer. It is unclear if oral calcium is beneficial for ovarian cancer prevention. Details: An older meta-analysis of 12 cohort studies found that dietary calcium intake is not associated with a reduced risk of ovarian cancer (38792). However, a more recent pooled analysis of 15 cohort and case-control studies has found that the highest intake of dietary or dairy calcium is associated with a 20% lower risk of ovarian cancer when compared to the lowest intake (97349).
• Postpartum depression. It is unclear if oral calcium is beneficial for reducing postpartum depression risk. Details: Preliminary clinical research shows that taking calcium 2 grams daily beginning at 11-21 weeks gestation reduces depression at 12 weeks postpartum when compared with placebo. However, no benefit is seen at 6 weeks postpartum (39447).
• Pregnancy-related leg cramps. It is unclear if oral calcium is beneficial for preventing leg cramps during pregnancy. Details: A small clinical study shows that taking calcium 1 gram twice daily (as a mixture of salts) for 2 weeks can reduce pregnancy-related leg cramps during the second half of pregnancy when compared with no treatment (2567).
• Prematurity. It is unclear if supplemental calcium is beneficial for the growth and development of preterm infants. Details: A small clinical study in preterm infants consuming human milk shows that supplementation with calcium 45 mg/kg daily and phosphorus 25 mg/kg daily does not affect infant weight, length, head circumference, or risk of osteopenia after 6 weeks when compared with human milk alone (113924). However, the duration and size of this study may have been too limited to detect any difference between groups.
• Preterm labor. It is unclear if oral calcium reduces the risk of preterm labor. Details: A meta-analysis of 10 clinical studies shows that taking calcium supplements during pregnancy does not reduce the risk of preterm labor when compared with placebo (113909). A separate meta-analysis of 7 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of preterm labor by 74% when compared with routine care (113913).
• Prostate cancer. It is unclear if oral calcium is beneficial for prostate cancer prevention. Details: Some clinical research shows that taking calcium 1200 mg daily might decrease the risk of developing prostate cancer (14133). However, some epidemiological research suggests that consuming very high doses of calcium, over 2000 mg daily, might actually increase the risk of developing prostate cancer (14134). Some epidemiological research also suggests that doses greater than 1500 mg daily increase the risk of poorly differentiated, clinically advanced, and fatal prostate cancer (14132). Consumption of dairy products has also been weakly linked to a modest increase in risk of prostate cancer (98894). However, contradictory research suggests that there is no association between dietary intake of calcium and overall risk of prostate cancer (14131,14132,104630).
• Stroke. It is unclear if oral calcium is beneficial for stroke prevention. Details: Some population research has found that increasing dietary calcium intake is associated with a decreased risk of ischemic stroke (4822,38678). However, other population research has found that increasing dietary calcium intake is not associated with a decreased risk of stroke (91350). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years does not affect the risk of stroke when compared with control. However, the majority of the included research evaluated postmenopausal females, and it is unclear if this finding is applicable to other populations (107233).
• Vertigo. Oral calcium with vitamin D might reduce positional vertigo; the effect of calcium when used alone is unclear. Details: A large clinical study in adults with recurrent benign paroxysmal positional vertigo shows that taking calcium 500 mg and vitamin D 400 IU twice daily for one year reduces annual recurrence of vertigo by 27% when compared with no treatment. The number needed to treat to prevent vertigo was 3.7 (103681). It is unclear if this benefit is due to vitamin D, calcium, or the combination. More evidence is needed to rate calcium for these uses.

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POSSIBLY INEFFECTIVE

• Bipolar disorder. Oral flaxseed oil does not seem to reduce symptoms of bipolar disorder in children. Details: Clinical research in children ages 6-17 years with bipolar disorder shows that taking flaxseed oil, titrated to provide up to 6.5 grams of the flaxseed oil constituent alpha-linolenic acid, daily for 16 weeks does not improve symptoms of mania or depression when compared with placebo (66044).
• Hyperlipidemia. Oral flaxseed oil does not seem to reduce cholesterol levels. Details: Although some evidence from preliminary, low-quality clinical studies disagrees (21698,26466,76696), most clinical research shows that taking flaxseed oil does not reduce cholesterol or triglyceride levels in patients with or without hypercholesterolemia or hypertriglyceridemia (2317,16791,16794,21693,21694,21696,21697,22177,72228,101947)(101954,101956,111062). A meta-analysis of clinical studies evaluating various flaxseed formulations suggests that flaxseed oil consumption may reduce apolipoprotein A levels, but not apolipoprotein B levels, when compared with control groups (108046). A subgroup analysis from another meta-analysis suggests that flaxseed oil may modestly improve levels of high-density lipoprotein cholesterol (108044). It should be noted that most research suggests that flaxseed, the source of flaxseed oil, can improve lipid levels in adults with hyperlipidemia. This difference may be due to lipid lowering components such as lignans, phytic acid, and polyphenols, that are found in flaxseed, but not flaxseed oil. See the Flaxseed monograph for more information.
• Obesity. Oral flaxseed oil does not seem to improve weight loss. Details: A meta-analysis of clinical research in overweight adults shows that flaxseed oil consumption does not reduce body weight, body mass index, or waist circumference when compared with control (96427). This is in contrast to research suggesting that flaxseed, the source of flaxseed oil, can improve weight loss in obese and overweight adults. See the Flaxseed monograph for more information.
• Rheumatoid arthritis (RA). Oral flaxseed oil does not seem to improve symptoms of RA. Details: A small clinical study in patients with RA shows that taking flaxseed oil daily for 3 months does not seem to improve symptoms of pain and stiffness, and has no effect on laboratory measures of RA, such as C-reactive protein and erythrocyte sedimentation rate (ESR), when compared with control (5898).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Atherosclerosis. Small clinical trials show that taking flaxseed oil has modest benefit on metabolic risk factors in patients with plaque in the coronary artery. Details: Observational research in White adults has found that high dietary intake of linolenic acid, a flaxseed oil constituent, is associated with reduced calcified atherosclerotic plaque in the coronary arteries (12990). However, clinical research has not confirmed this finding. A small clinical trial in patients with coronary artery disease shows that taking flaxseed oil 5 grams in milk containing 1.5% fat reduces triglyceride levels by 14% when compared with the milk alone. However, there was no effect on systolic blood pressure, high-density lipoprotein (HDL) cholesterol, or low-density lipoprotein (LDL) cholesterol (101954). Additionally, another small study in a similar patient population shows that taking flaxseed oil 2 grams daily for 12 weeks has no effect on lipid levels when compared with placebo (101956).
• Attention deficit-hyperactivity disorder (ADHD). Oral flaxseed oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in children with ADHD shows that taking flaxseed oil, providing 200 mg of alpha-linolenic acid, in combination with vitamin C 25 mg, twice daily can improve measures of attention, impulsivity, restlessness, and self-control when compared to baseline (14443). This finding is limited by the lack of a control group. Furthermore, it is unclear if the benefit is due to flaxseed oil, vitamin C, or the combination.
• Breast cancer. It is unclear if oral flaxseed oil reduces the risk of breast cancer. Details: Population research has found that females with higher levels of the flaxseed oil constituent, alpha-linolenic acid (ALA), in breast adipose tissue have a lower risk of breast cancer. Fatty acid composition of adipose tissue is thought to reflect past dietary intake, so researchers think high intake of ALA might have a cancer protective effect (7168,21689). Flaxseed oil is one source of ALA; it is unclear what effect, if any, flaxseed oil has on breast cancer risk.
• Burns. It is unclear if oral flaxseed oil improves wound healing and health in people with burns. Details: A small clinical trial in patients with mild to moderate burns shows that eating cookies containing flaxseed oil 30 grams and isolated soy protein (ISP) 50 grams daily for 3 weeks improves the rate of wound healing when compared with control cookies. It seems to take at least 3 weeks before this difference is observed. However, there is no significant difference in the rate of wound healing when compared with cookies containing ISP with corn oil (99401). It is possible that the study was underpowered to detect a difference between these two groups.
• Cardiovascular disease (CVD). It is unclear if oral flaxseed oil reduces the risk of CVD. Details: Flaxseed oil is a source of alpha-linolenic acid (ALA). A meta-analysis of observational studies has found that, overall, increasing dietary intake of ALA by 1.2 grams daily is associated with a 20% reduced risk of fatal coronary heart disease in people with existing heart disease (12978). Some research suggests that ALA has a greater impact on coronary heart disease when intake of fish oils is low (12989). It is unknown if flaxseed oil supplements have these same effects. Additionally, it is difficult to separate effects of dietary ALA in these studies from those of other dietary, lifestyle, or drug interventions (12917).
• Carpal tunnel syndrome. It is unclear if topical flaxseed oil reduces carpal tunnel pain. Details: Preliminary clinical research in patients with carpal tunnel syndrome who wear a wrist splint at night shows that applying flaxseed oil 5 drops topically on the palmar wrist twice daily for 4 weeks improves subjective symptom scores by 30%, function scores by 17%, and sensory nerve conduction velocity of the median nerve by about 7% when compared to baseline. Compared to the changes observed for patients in the placebo group, these improvements were significant (25691). It is unclear if this benefit persists long-term or how topical flaxseed oil compares to other standard treatments for carpal tunnel syndrome.
• Chronic kidney disease (CKD). Although there is interest in using oral flaxseed oil for CKD, there is insufficient reliable information about the clinical effects of flaxseed for this condition.
• Cognitive function. It is unclear if oral flaxseed oil improves cognitive function in healthy adults. Details: Clinical research in healthy older Japanese adults with normal cognitive function shows that taking flaxseed oil 3.7 grams daily for 12 weeks modestly improves verbal fluency when compared with taking placebo. However, there was no effect on other measures of cognitive function, including attention, concentration, and memory (111060).
• Diabetes. Oral flaxseed oil may not improve glycemic control in patients with type 2 diabetes. However, there may be some benefit in patients with gestational diabetes. Details: Most clinical research in patients with type 2 diabetes shows that taking flaxseed oil, providing about 1-16 grams of alpha-linolenic acid, daily for up to 6 months does not improve fasting blood glucose, glycated hemoglobin (HbA1C), or insulin resistance when compared with placebo (16792,66065,96428,96431,101956,111062). While taking flaxseed oil does not seem to be beneficial for type 2 diabetes, it might improve outcomes in gestational diabetes. A small clinical study in pregnant patients (24-28 weeks gestation) with gestational diabetes shows that taking flaxseed oil 1 gram twice daily for 6 weeks reduces fasting levels of glucose and insulin and improves insulin resistance when compared with placebo (101957). Another small clinical study in patients with gestational diabetes shows that taking flaxseed oil 1 gram, containing 400 mg of alpha-linolenic acid, along with vitamin E 400 IU daily for 6 weeks reduces blood glucose levels, insulin levels, and insulin resistance and improves beta-cell function when compared with placebo (96432). It is unclear if the findings from this latter study are due to flaxseed oil, vitamin E, or the combination.
• Diabetic foot ulcers. It is unclear if oral flaxseed oil improves the healing of diabetic foot ulcers. Details: One small clinical trial in adults with grade 3 diabetic foot ulcers shows that taking flaxseed oil 1 gram twice daily for 12 weeks in conjunction with intravenous antibiotics for the first 3 weeks reduces ulcer size when compared with placebo (96431).
• Dry eye. Flaxseed oil, both orally and as an eye drop, has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with dry eye shows that taking a specific combination product (TheraTears Nutrition, Advanced Vision Research) containing eicosapentaenoic acid 450 mg, docosahexaenoic acid 300 mg, and flaxseed oil 1000 mg daily for 90 days reduces subjective symptoms of dry eye and might increase tear production when compared with placebo. However, it did not improve meibomian gland secretions or tear evaporation rate when compared with placebo (17523). Eye drops with flaxseed oil have also been tried for dry eye. A clinical study shows that using a specific product (Refresh Optive MEGA-3 Preservative-Free Lubricant Eye Drops, Allergan plc) which contains flaxseed oil and trehalose in addition to other ingredients such as carboxymethylcellulose (CMC) and castor oil twice daily for 90 days improves dry eye symptoms when compared to baseline, but not when compared with the same eye drops formulated without flaxseed oil and trehalose (101953).
• Dry skin. There is conflicting evidence regarding the use of flaxseed oil for dry skin. Details: Some clinical research suggests that taking flaxseed oil 2.2 grams orally in combination with alpha-tocopherol 10 mg daily for 12 weeks does not improve skin hydration when compared with placebo or borage oil in females with dry skin, although the combination seems to improve the sensitivity of dry skin (21908). Other clinical research suggests that taking flaxseed oil 2.2 grams daily for 12 weeks improves skin hydration and roughness when compared with safflower oil (21909).
• Endometrial hyperplasia. It is unclear if oral flaxseed oil reduces endometrial hyperplasia. Details: A small clinical trial in adults with endometrial hyperplasia shows that taking flaxseed oil 1 gram twice daily for 12 weeks does not induce endometrial regression or reduce cholesterol levels when compared with placebo. However, there appears to be a small benefit on fasting plasma glucose and insulin levels (101955).
• Hypertension. Small studies suggest that flaxseed oil may modestly lower blood pressure in some patients. Details: Epidemiological research has found that high dietary intake of linolenic acid, a flaxseed oil constituent, is associated with a reduced risk of developing hypertension (12991). Meta-analyses of small clinical studies in patients with and without hypertension show that receiving flaxseed oil 1.2-30 grams daily for 4-24 weeks reduces systolic and diastolic blood pressure by 0.5 mmHg to 4 mmHg, when compared with control (96426,111063). One meta-analysis limited to small clinical trials in patients with metabolic syndrome, hypercholesterolemia, or hypertension, shows that taking flaxseed oil 25 mL or 2.2 to 9.2 grams daily for 7-12 weeks reduces systolic blood pressure by about 3.9 mmHg; however, there is no effect on diastolic blood pressure (111067). The small size and heterogeneity of the studies included in these meta-analysis limit the validity of these findings. Also, the effect of taking flaxseed oil in patients specifically with hypertension is unclear from this available research. Flaxseed oil has also been evaluated in combination with other oils and dietary interventions, with mixed evidence of benefit. Flaxseed oil 19 grams, providing 10.5 grams of alpha-linolenic acid, seems to reduce blood pressure when combined with walnuts and walnut oil daily for 6 weeks (21905). However, consuming 60 grams of a combination of flaxseed and safflower oils in a 6:4 ratio daily for 4 weeks does not seem to affect blood pressure when compared with baseline (26466).
• Mastalgia. It is unclear if oral flaxseed oil is beneficial in patients with mastalgia. Details: A clinical study in adults with fibrocystic breasts and mastalgia shows that taking flaxseed oil 1000 mg containing 350 mg alpha-linolenic acid twice daily for 2 months reduces pain when compared with baseline, but is no different than taking vitamin E 200 IU daily (105477).
• Metabolic syndrome. It is unclear if oral flaxseed oil is beneficial in patients with metabolic syndrome. Details: A small clinical study in patients with metabolic syndrome shows that taking flaxseed oil 20 mL daily for 7 weeks does not improve coagulation scores based on prothrombin time, partial thromboplastin time, and the international normalized ratio (INR) when compared with sunflower oil (101951).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral flaxseed oil is beneficial in patients with NAFLD. Details: Clinical research in overweight or obese patients with NAFLD shows that taking flaxseed oil 20 grams daily for 12 weeks as part of a hypocaloric diet improves the grade of fatty liver by 41%, compared with 18% in patients taking sunflower oil. There was also a small effect on body mass index, although there was no effect on liver enzymes, glycemic control, or body composition (101952).
• Parkinson disease. Oral flaxseed oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with Parkinson disease shows that taking flaxseed oil 1 gram daily plus vitamin E 400 IU daily for 12 weeks improves the Unified Parkinson Disease Rating Scale (UPDRS) total score by 3.3 points, compared to a 4.4-point worsening in the placebo group (96430). However, it is unclear if this change is clinically meaningful. The minimal clinically important improvement in UPDRS total score is 4.3 points, while a moderate improvement ranges from 9 to 17 points (95686). Also, it is not clear if these findings are due to flaxseed oil, vitamin E, or the combination.
• Physical performance. It is unclear if oral flaxseed oil improves physical performance in older adults. Details: A small clinical study in elderly adults without previous exercise training suggests that flaxseed oil containing alpha-linolenic acid does not improve muscle strength when compared with placebo (65937).
• Pneumonia. It is unclear if oral flaxseed oil helps to prevent pneumonia. Details: Epidemiological research has found that increasing dietary alpha-linolenic acid, which occurs in flaxseed oil, is associated with a reduced risk of community-acquired pneumonia (13760). However, this research did not specifically assess the effect of flaxseed oil intake on pneumonia.
• Polycystic ovary syndrome (PCOS). Small clinical studies suggest that oral flaxseed oil might help to improve some markers of PCOS. Details: A small clinical study in patients with PCOS shows that taking flaxseed oil, providing 545 mg of alpha-linolenic acid, for 6 weeks lowers triglycerides but does not affect weight, hormone levels, glycemic control, or cholesterol levels when compared to baseline (21906). This finding is limited by the lack of a control group. Another small clinical study in patients with PCOS shows that taking flaxseed oil, providing 1 gram of omega-3 fatty acids, twice daily in addition to metformin for 12 weeks decreases triglyceride and insulin levels, but does not affect fasting blood glucose, testosterone levels, free androgen index, or total cholesterol when compared with placebo (99402).
• Prostate cancer. Oral flaxseed oil does not seem to be linked to prostate cancer risk. Details: Although some epidemiologic research has found that high dietary intake of alpha-linolenic acid, a constituent of flaxseed oil, is associated with an increased risk for prostate cancer (1334,1337,2558,7823,7147,12978,12961), other research has found no association (12961,15736). Furthermore, it appears that alpha-linolenic acid from plant sources, such as flaxseed or flaxseed oil, does not increase prostate cancer risk (12909).
• Ulcerative colitis. It is unclear if oral flaxseed oil is beneficial in patients with ulcerative colitis. Details: A small open-label clinical study in patients with ulcerative colitis shows that taking flaxseed oil 10 grams daily for 12 weeks seems to modestly reduce inflammatory markers and disease severity and improve quality of life when compared with control (101941). More evidence is needed to rate flaxseed oil for these uses.

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POSSIBLY EFFECTIVE

• Antibiotic-associated diarrhea. Most research shows that oral Lactobacillus acidophilus, alone or in combination with other probiotics, seems to reduce the risk of antibiotic-associated diarrhea (AAD) in adults. Details: A meta-analysis of 18 clinical trials in hospitalized or outpatient adults shows that taking L. acidophilus alone or in combination with up to 8 other probiotic strains reduces the risk of AAD by 34% when compared with taking placebo (107635). One small clinical trial in elderly adults shows that AAD occurred in 17% of those taking L. acidophilus (Florajen Acidophilus) 20 billion colony-forming units (CFUs) three times daily, compared with 37% of those taking placebo (95400). A number of combination products have also demonstrated benefit for preventing AAD, including Bio-K+ Cl1285 which provides L. acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2 as 100 billion CFUs daily (25494,95402,95403); L. acidophilus and Bifidobacterium animalis subsp. lactis (90239); and Ecologic AAD which provides L. acidophilus NIZO 3678 and NIZO 3887, Lacticaseibacillus paracasei NIZO 3672, Lactiplantibacillus plantarum NIZO 3684, L. rhamnosus NIZO 3689, Ligilactobacillus salivarius NIZO 3675, Bifidobacterium bifidum NIZO 3804, Bifidobacterium animalis subsp. lactis NIZO 3680, and Enterococcus faecium NIZO 3886 (95405). However, some combination products have not demonstrated benefit. Clinical research shows that taking a combination of L. acidophilus and bifidobacteria or a combination of L. acidophilus and Lactobacillus delbrueckii subsp. bulgaricus (Lactinex) is not beneficial (90231,90239,92255,95385). An additional large clinical trial in children aged 3 months and up shows that taking L. acidophilus in combination with other probiotics does not reduce the risk of antibiotic-associated diarrhea when compared with taking placebo, when the more stringent definition is considered excluding diarrhea of other etiologies. However, the risk of diarrhea of any etiology is reduced by 35%. The probiotic supplement provided a total of 10 billion CFUs of L. acidophilus W37, Bifidobacterium bifidum W23, Bifidobacterium animalis subsp. lactis W51, Lactobacillus acidophilus W55, Lacticaseibacillus paracasei W20, Lactiplantibacillus plantarum W62, Lacticaseibacillus rhamnosus W71, and Ligilactobacillus salivarius W24 daily from the first day of antibiotic treatment until 7 days after treatment ended (110969).
• Bacterial vaginosis. Most clinical research shows that intravaginal application of Lactobacillus acidophilus may be helpful for the treatment of bacterial vaginosis. It is unclear if oral L. acidophilus is beneficial for the treatment or prevention of bacterial vaginosis. Details: One clinical trial shows that intravaginal suppositories containing 100 million to 1 billion colony-forming units (CFUs) of L. acidophilus (Vivag, Pharma Vinci A/S) given twice daily for 6 days improve bacterial vaginosis resolution rates when compared with placebo (13177). Another clinical trial shows that using 1-2 vaginal tablets containing viable L. acidophilus 10 million CFUs and estriol 0.03 mg per tablet (Gynoflor, Medinova) daily for 6 days increases cure rates when compared with placebo (13176). However, using this product in combination with metronidazole 400 mg twice daily for 7 days does not improve outcomes when compared with metronidazole alone (90237). Preliminary clinical research in patients with clinically defined bacterial vaginosis shows that daily intravaginal application with a douche providing L. acidophilus 1 billion CFUs per mL for 6 days might have beneficial effects on the vaginal flora. When compared with 52.5% of patients with bacterial vaginosis based on bacterial flora at baseline, 7.5% met this criteria 14 days after treatment had been completed (111788). Oral L. acidophilus has also been evaluated. Preliminary clinical research shows that eating yogurt 125 mL daily enriched with L. acidophilus for 2 months might slightly decrease the incidence of recurrent bacterial vaginosis (1245). L. acidophilus has also been investigated in an oral formulation in combination with other probiotics. Clinical research in patients with bacterial vaginosis cured within the past 48 hours shows that taking a product containing L. acidophilus in combination with other probiotics results in recurrence of vaginosis in 18.3% of patients, a statistically significant reduction compared with 32.1% of those using placebo. The mean time to recurrence was approximately 23 days longer in patients taking the lactobacilli. The product contained L. acidophilus 1.08 billion CFUs along with Lactobacillus crispatus LMG S-29995 and Levilactobacillus brevis (Lactogyn, Vésale Pharma, Belgium), and was taken twice daily for 7 days and then once daily for up to an additional 120 days (110950).
• Helicobacter pylori. Oral Lactobacillus acidophilus, usually in combination with other probiotics, seems to improve H. pylori eradication when used along with standard therapies. It is unclear if heat-killed L. acidophilus is beneficial for H. pylori eradication. Details: A meta-analysis of clinical studies utilizing probiotic products containing L. acidophilus shows that these products can improve H. pylori eradication rates 1.14- to 1.24-fold when taken in combination with triple therapy consisting of a proton-pump inhibitor (PPI), clarithromycin, and amoxicillin. Based on these results, about 7-11 patients would need to be treated in order for one additional patient to achieve complete remission (95394). Only one of the trials in this analysis investigated L. acidophilus alone; an additional 8 used L. acidophilus in combination with other probiotics. Individual clinical trials have shown that a combination of L. acidophilus, Enterococcus faecalis, and Bacillus subtilis 30 million colony-forming units (CFUs) total, taken in three divided doses daily, from 2 weeks prior tol 2 weeks after triple therapy increases H. pylori eradication when compared with triple therapy alone (90248). In children, a combination of L. acidophilus (strain 5) 94 million CFUs and Bifidobacterium bifidum (strain 12) 8.6 million CFUs in combination with a PPI, clarithromycin, and amoxicillin or metronidazole has been used daily for 2 weeks, followed by the probiotics alone for an additional 4 weeks (90602). However, other individual clinical trials have shown that L. acidophilus in combination with Lacticaseibacillus rhamnosus, Bifidobacterium bifidum, and Streptococcus faecium may not improve eradication rates when taken with triple therapy consisting of furazolidone, tetracycline, and lansoprazole (90279). Also, taking L. acidophilus along with six other probiotics in conjunction with bismuth quadruple therapy does not seem to improve H. pylori eradication rates when compared with placebo and bismuth quadruple therapy (90291). Also, taking L. acidophilus and L. casei without any standard H. pylori therapy does not improve H. pylori eradication rates in adults (12766). Heat-killed L. acidophilus has also been investigated in adults with H. pylori. Taking a lyophilized and inactivated culture of L. acidophilus (Lacteol Fort) containing 5 billion cells, 3 times daily for 10 days, modestly increases the eradication rate in patients using triple therapy of rabeprazole, clarithromycin, and amoxicillin for 7 days (8562).
• Irritable bowel syndrome (IBS). Some research shows that oral live Lactobacillus acidophilus, taken alone or in combination with other probiotics, may be beneficial for IBS. The effects of non-viable, heat-killed L. acidophilus are unclear. Details: Clinical research in adults with IBS shows that taking L. acidophilus DDS-1 10 billion colony-forming units (CFUs) daily for 6 weeks modestly reduces the severity of abdominal pain when compared with placebo. Also, 52% of patients experienced a more than 30% reduction in pain severity, compared with 16% of those taking placebo. There were also improvements in abdominal distention and duration of pain; however, there were no changes in bowel habits (107581). A meta-analysis shows that taking L. acidophilus improves the rate of symptom relief and reduces bloating severity when compared with placebo. However, other symptoms were not improved (110866). L. acidophilus has also been examined in combination with other probiotics. One clinical study shows that taking a specific combination product (Visbiome, ExeGi Pharma) containing L. acidophilus and 7 other species as 450 billion CFUs daily in two divided doses for 8 weeks improves abdominal bloating, but not abdominal pain, flatulence, or number of stools, in patients with diarrhea-predominant IBS (IBS-D) (11379). Another clinical study in patients with IBS-D shows that taking a specific multi-species probiotic (NordBiotic, MBM Biotix) containing L. acidophilus LA120, Lacticaseibacillus rhamnosus LR110, Lacticaseibacillus paracasei LPC100, Lacticaseibacillus casei LC130, Lactiplantibacillus plantarum LP140, Bifidobacterium breve BB010, Bifidobacterium longum BL020, Bifidobacterium bifidum BF030, Bifidobacterium animalis subsp. lactis BL040, and Streptococcus thermophilus ST250 as 2.5 billion CFUs total twice daily for 8 weeks improves overall symptom severity, as well as pain severity, pain frequency, and quality of life, when compared with placebo. Symptom severity was rated as mild by approximately 60% of those taking the probiotic mixture, compared with 30% of those taking placebo (107516). A small clinical trial shows that taking L. acidophilus NCFM plus Lactobacillus helveticus Lafti L10 (Lallemand Health Solutions) 5 billion CFUs each daily for 8 weeks modestly reduces flatus and overall symptoms, but not abdominal pain or bloating, when compared with taking placebo (111785). However, other probiotic compounds containing L. acidophilus have not demonstrated benefit in most patients with IBS. These include L. acidophilus NCFM 10 billion CFUs daily for 12 weeks; L. acidophilus, L. paracasei, and Bifidobacterium animalis subsp. lactis BB-12 (Cultura) 13-20 billion CFUs daily for 6 months; or L. acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2 50 billion CFUs each daily for 3 months (90236,94696,94697,95365,99789). Further research is needed to determine which IBS subtype, if any, is most likely to benefit. Heat-killed L. acidophilus has also been investigated in patients with IBS. One clinical study shows that taking capsules containing heat-killed L. acidophilus (Lacteol Fort) 20 billion colony-forming units (CFUs) daily for 6 weeks improves abdominal pain, bloating, and number and quality of stools when compared with placebo (7744). Also, in patients with IBS-D, observational research has found that use of heat-killed L. acidophilus (Lacteol LB) two capsules daily for one month modestly reduces pain and bloating and improves quality of life. The average weekly number of stools decreased by approximately 4.75. Also, the number of patients with watery stools was reduced from 54% at baseline to 19% (107535).

POSSIBLY INEFFECTIVE

• Atopic disease. Oral Lactobacillus acidophilus does not seem to be beneficial for preventing atopic disease in children. Details: A meta-analysis of clinical research shows that administering L. acidophilus during pregnancy, when breastfeeding, or to newborn infants might actually increase the risk of atopic sensitization (90251). However, the number of studies included in this analysis was limited.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A preliminary clinical study shows that taking a specific probiotic product containing L. acidophilus 5 billion colony-forming units (CFUs), Lactobacillus delbrueckii subsp. bulgaricus 5 billion CFUs, and Bifidobacterium bifidum 20 billion CFUs (Trenev Trio/Healthy Trinity, Natren) twice daily along with minocycline once every evening for 12 weeks improves inflamed and non-inflamed acne lesions in 82% of patients, compared to only 67% of patients treated with either the probiotic combination or minocycline alone (90270).
• Acute respiratory distress syndrome (ARDS). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in premature infants shows that taking 6 billion CFUs of a combination of L. acidophilus NCDO 1748 and Bifidobacterium bifidum NCDO 2203 (UFC Inforan, Switzerland) from 7 days of age until 34 weeks postmenstrual age or discharge does not reduce the odds of ARDS when compared with a control group of infants not given these probiotics. The infants in this study were born at less than 32 weeks gestation and had a birthweight of less than 1500 grams (111794). This study is limited by the lack of randomization to treatment group; placement was based on year of birth.
• Allergic rhinitis (hay fever). It is unclear if oral Lactobacillus acidophilus is beneficial for allergic rhinitis prevention or treatment. Details: A small clinical trial in patients with perennial allergic rhinitis shows that taking heat-treated milk fermented with L. acidophilus L-92 100 mL daily for 8 weeks modestly reduces nasal symptoms and mucus, but not ocular symptoms, when compared with taking an acidified placebo milk. The milk provided approximately 30 billion L. acidophilus cells (25488). The effect of L. acidophilus as a probiotic is unclear from this study. Other clinical research shows that drinking 250 mL of fermented milk containing L. acidophilus La-5 5 billion colony-forming units (CFUs), Lacticaseibacillus rhamnosus GG 50 billion CFUs, and Bifidobacterium animalis subsp. lactis BB-12 50 billion CFUs from 36 weeks' gestation until 3 months postpartum does not reduce the incidence of allergic rhinitis in the child at 6 years of age when compared with placebo milk (96893).
• Asthma. It is unclear if oral Lactobacillus acidophilus can improve lung function in people with asthma. Details: A small clinical crossover study in patients with moderate asthma shows that consuming live active yogurt 225 grams, providing L. acidophilus 760 million colony-forming units (CFUs) per gram, twice daily for 1 month does not affect measures of lung function when compared with yogurt not containing L. acidophilus. All yogurt contained Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (1244).
• Atopic dermatitis (eczema). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of the available clinical research shows that intake of lactobacilli and bifidobacteria-based probiotics during gestation, followed by giving the probiotic to the newborn for the first 2-6 months of life, reduces the risk of developing atopic dermatitis by 40% over the next 6-24 months when compared with placebo, regardless of family history of atopy. However, only four of 10 studies included in the analysis used L. acidophilus as part of the probiotic combination; the results from these individual, small studies support the overall findings of the meta-analysis (107503). Some clinical research also shows that supplementation with 250 mL of fermented milk containing L. acidophilus La-5, Lacticaseibacillus rhamnosus GG, and Bifidobacterium animalis subsp. lactis BB-12 starting at 36 weeks' gestation and continuing until 3 months' postpartum, without supplementation in the infant, reduces the overall occurrence of atopic dermatitis in the child at 2 years of age. However, at 6 years of age, the effect appears to be inconclusive (96893). In children ages 1-3 years with moderate to severe atopic dermatitis, taking 5 billion colony-forming units (CFUs) of a combination of L. acidophilus DDS-1 and Bifidobacterium animalis subsp. lactis UABLA-12 along with fructo-oligosaccharides (FOS) (DDS Junior) twice daily for 8 weeks modestly reduces symptom severity and the need for topical corticosteroids when compared with placebo (110995).
• Bronchopulmonary dysplasia. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One large observational study in premature infants suggests that taking L. acidophilus 1 to 3 billion CFUs with Bifidobacterium longum subsp. infantis during the first month of life for the prevention of necrotizing enterocolitis was not associated with a reduced risk of bronchopulmonary dysplasia. The infants in this study were born between 22-29 weeks gestation and had a birthweight of less than 1500 grams (111771).
• Cancer. Although there has been interest in using oral Lactobacillus acidophilus for cancer prevention or treatment, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• Canker sores. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A systematic review and meta-analysis of mainly small and preliminary clinical trials shows that taking lactobacilli probiotics has a small effect on pain from canker sores. However, the dose and duration of probiotic and the specific species, as well as endpoints and results from individual studies, are mixed. One small study shows that taking a combination of L. acidophilus, Lacticaseibacillus paracasei, Lacticaseibacillus rhamnosus, and Bifidobacterium animalis subsp. lactis reduces pain, but not the number of lesions or healing time, when compared with placebo. Another study shows that using lozenges providing inulin 0.13 gram along with L. acidophilus and B. animalis subsp. lactis 1.5 billion colony-forming units each reduces pain, but does not affect ulcer size or healing, when compared with Oracure gel (105146). Many of the individual studies may have been underpowered to detect a difference between groups.
• Cholestasis. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in premature infants shows that the risk of developing cholestasis is reduced from 22% to 6% in those given a blend of L. acidophilus, bifidobacteria, and Enterococcus faecalis (Peifeikang powder, Shanghai Xinyi Pharmaceutical Company) at least 5 million colony-forming units three times daily, from birth until implementation of total parenteral nutrition, when compared with infants not given this powder. In the infants that developed cholestasis, the severity was reduced, resulting in a reduction in the rate of cholestatic liver injury, feeding intolerance, and necrotizing enterocolitis. The number of days to reach full enteral feeding, days to normal weight gain, and days of hospitalization were reduced by approximately 2.8, 2.1, and 1.7 days, respectively (103448).
• Clostridioides difficile infection. It is unclear if oral Lactobacillus acidophilus is beneficial for preventing C. difficile occurrence or recurrence. Details: Current guidelines from the Infectious Diseases Society of America (IDSA) state that there is insufficient information to recommend administration of probiotics for the primary prevention of C. difficile-associated diarrhea (107538). Evidence from clinical and observational research investigating the effect of L. acidophilus on C. difficile occurrence or recurrence is weak. Most studies use this species in combination with one or more additional probiotic species, including as Bio-K+ CI1285, containing L. acidophilus CL1285 and L. casei LBC80R, and as Bio-K+ 50 Billion, containing L. acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2 (25494,90231,90934,95369,95403,107529). Observational research has found that providing the Bio-K+ 50 Billion product as 50-100 billion colony-forming units (CFUs) daily for 5 days to patients who are on antibiotics for at least 2 days reduces the hospital-wide incidence of C. difficile by approximately 40%. The incidence rate was decreased by at least 50% in the highest risk individuals taking this combination (107529).
• Colic. Oral inactivated Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study in infants with colic shows that giving a specific multi-ingredient product (Colimil Plus, Milte Italia SPA) containing inactivated L. acidophilus 1 billion colony-forming units, lemon balm 65 mg, and German chamomile 9 mg twice daily for 4 weeks reduces crying time similarly to Limosilactobacillus reuteri DSM 17938 100 million CFUs daily (96278). It is unclear how L. acidophilus compares with no treatment.
• Common cold. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in school children shows that taking a combination of L. acidophilus and Bifidobacterium bifidum (Infloran, Berna) 1 billion colony-forming units each twice daily for 3 months reduces the absolute percentage of school absence due to cold symptoms by 30% when compared with placebo (90286).
• Constipation. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that stool frequency is increased and symptoms of functional constipation in adults are improved with the use of a specific combination product (Hexbio) providing L. acidophilus, Lacticaseibacillus casei, Lactobacillus delbrueckii subsp. lactis, Bifidobacterium bifidum, Bifidobacterium longum, and Bifidobacterium longum subsp. infantis 30 billion colony-forming units (CFUs) twice daily for 7 days (90266). However, most other probiotic compounds containing L. acidophilus have not demonstrated benefit in most patients with constipation. One small clinical trial shows that taking yogurt 180 mL providing L. acidophilus NCFM, Bifidobacterium animalis subsp. lactis HN019, and polydextrose (Litesse) daily for 2 weeks modestly improves clinical response and reduces transit time when compared with taking a control yogurt. However, there was no effect on the number of daily bowel movements (90275). Other studies show that taking Lactobacillus acidophilus DDS-1 6.6 billion CFUs daily for 4 weeks in combination with Bifidobacterium longum UABl-14, Bifidobacterium animalis subsp. lactis UABla-12, Bifidobacterium bifidum UABb-10, and fructo-oligosaccharides (FOS) 7 mg does not improve symptoms of constipation when compared with a placebo providing FOS (110970). Also, there was a general lack of support for symptom improvement following the intake of Lactobacillus acidophilus NCFM 10 billion CFUs daily with Lacticaseibacillus paracasei Lpc-37 and Bifidobacterium animalis subsp. lactis strains Bl-04, Bi-07, and HN019 daily for 2 weeks (110979).
• Critical illness (trauma). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in critically ill, hospitalized adults shows that taking L. acidophilus LA-5 1.75 billion colony-forming units (CFUs), Lactiplantibacillus plantarum 500 million CFUs, Bifidobacterium animalis subsp. lactis BB12 1.75 billion CFUs, and Saccharomyces boulardii 1.5 billion CFUs twice daily for 15 days modestly reduces the risk of sepsis, as well as the length of stay in the ICU and hospital, when compared with placebo (107524).
• Denture stomatitis. Although there has been interest in using oral Lactobacillus acidophilus for denture stomatitis, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• Depression. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with major depression shows that taking L. acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum daily for 8 weeks reduces symptoms of depression measured on the Beck Depression Inventory (BDI) when compared with placebo (99780). However, the validity of the results from this study is limited by incomplete reporting. For example, patient baseline BDI scores were not reported.
• Diabetes. Oral Lactobacillus acidophilus in combination with other probiotic species seems to be beneficial for the treatment of gestational diabetes, although it is unclear if it is beneficial for treatment of type 1 or type 2 diabetes. Oral L. acidophilus is unlikely to be beneficial for the prevention of gestational diabetes. Details: Although some individual studies disagree, meta-analyses of clinical research in patients with gestational diabetes show that taking probiotics, most often L. acidophilus in combination with other species, improves glycemic indices such as fasting blood glucose and insulin sensitivity when compared with placebo (102288,104156). Also, one meta-analysis of clinical research shows that taking probiotics specifically containing L. acidophilus in combination with other species modestly improves these glycemic indices, as well as levels of total cholesterol and triglycerides, but not low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol (111796). Some doses used in available studies include a combination of freeze-dried L. acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum each as 2 billion colony-forming units (CFUs) per gram daily for 6 weeks (95416,98430), a total of 4 billion CFUs of a combination of L. acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12, Streptococcus thermophilus STY-31, and Lactobacillus delbrueckii subsp. bulgaricus LBY-27 for 8 weeks starting at 24-28 weeks' gestation (96892), and a specific product containing L. acidophilus and 7 other probiotics (Visbiome, ExeGi Pharma) as a total of 112.5 billion CFUs twice daily for 8 weeks (107549). Meta-analyses in patients with gestational diabetes show that taking probiotics such as L. acidophilus does not reduce the risk for caesarean section birth, neonatal hypoglycemia, large for gestational age birth, or hypertensive disorders such as pregnancy-induced hypertension, pre-eclampsia, or eclampsia (102288,104156,111796). However, one meta-analysis of clinical research shows that taking probiotics specifically containing L. acidophilus modestly reduces neonatal birth weight, but not maternal weight gain (111796). Taking L. acidophilus does not seem to be effective for PREVENTING gestational diabetes. A large clinical trial shows that taking L. acidophilus LA1 7.5 billion CFUs, Bifidobacterium longum sp54 cs 1.5 billion CFUs, and Bifidobacterium bifidum sp9 cs 6 billion CFUs daily from 14-24 weeks' gestation does not reduce the incidence of gestational diabetes when compared with taking placebo (107520). Research on the use of L. acidophilus for type 2 diabetes is mixed. Taking a combination of L. acidophilus, Bifidobacterium bifidum, and Streptococcus thermophilus daily for 12 weeks does not reduce levels of fasting blood glucose or glycated hemoglobin (HbA1c) when compared with placebo (107521). One clinical study shows that taking L. acidophilus along with six other probiotic strains (Familact) daily for 6 weeks reduces fasting blood glucose, but does not affect plasma insulin, when compared with placebo (99790). A small clinical trial shows that taking fermented goat milk 120 grams containing one billion CFUs each of L. acidophilus La-5 and Bifidobacterium animalis subsp. lactis BB-12 daily for 6 weeks modestly reduces levels of HbA1c and low-density lipoprotein (LDL) cholesterol, but not fasting blood glucose or insulin resistance, when compared with conventional fermented milk containing Streptococcus thermophilus TA-40 (110973). However, other clinical research shows that taking L. acidophilus 1 billion CFUs, along with Lacticaseibacillus rhamnosus, Bacillus coagulans GanedenBC30 (GBI-30, 6086), and fructo-oligosaccharides 500 mg daily for 12 weeks modestly reduces fasting blood glucose and insulin and improves measures of insulin resistance when compared with placebo (107731). Another clinical trial shows that taking yogurt 200 grams daily containing L. acidophilus 4.65 million CFUs per gram along with Bifidobacterium animalis subsp. lactis modestly reduces levels of HbA1c, triglyceride, and LDL cholesterol, but not fasting glucose, when compared with a placebo yogurt (111798). A combination probiotic containing L. acidophilus has also been evaluated in children 2-12 years of age with new-onset type 1 diabetes. One clinical study shows that taking a specific combination product (Visbiome, ExeGi Pharma) providing 112.5 billion CFUs daily for 3 months modestly decreases HbA1c and insulin requirements when compared with placebo. Also, about three times as many children achieved remission, defined as insulin requirements of less than 0.5 U/kg daily and HbA1c less than 7%. However, C-peptide levels and the maintenance of residual pancreatic beta-cell function were not affected when compared with placebo (107497).
• Diabetic nephropathy. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with diabetic nephropathy not taking antidiabetes drugs shows that taking a combination of L. acidophilus, Bifidobacterium bifidum, and Streptococcus thermophilus daily for 12 weeks modestly reduces the ratio of microalbuminuria/creatinine (mAlb/Cr), a marker of kidney damage, when compared with placebo. However, there was no effect on the estimated glomerular filtration rate (eGFR) (107521).
• Diarrhea. Oral heat-killed L. acidophilus seems to reduce the duration of diarrhea in adults and children. Oral live L. acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children with dysentery being treated with ceftriaxone shows that taking a specific combination probiotic sachet (Kidilact, Zisttakhmir Company) containing live L. acidophilus, Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium longum subsp. infantis, Bifidobacterium breve, and Streptococcus thermophilus daily for 5 days modestly reduces the duration of diarrhea, hospitalization, and blood in diarrhea when compared with control (102417). Heat-killed L. acidophilus has also been investigated for the treatment of diarrhea. A meta-analysis of four small clinical studies in infants and children ages 1 month to 4 years shows that taking heat-killed L. acidophilus LB 20-30 billion colony-forming units (CFUs) daily for up to 5 days along with oral or intravenous rehydration therapy can modestly reduce the duration of diarrhea, primarily of non-rotaviral origin (90295). Also, preliminary clinical research in patients with functional chronic diarrhea shows that taking heat-killed L. acidophilus LB (Lacteol Fort, Laboratoire du Lacteol du Dr Boucard) as two capsules twice daily for a total of 20 billion cells daily for 4 weeks reduces daily stool frequency by 3.5, compared with a reduction of 1.2 in patients taking five chewable capsules three times daily of an unspecified strain of L. acidophilus (Lacidophilin, Tai Ge Pharma Ltd). Stool consistency, pain, distention, and total efficacy, defined as a decrease in mean symptoms by at least 40%, were also further improved in patients taking the heat-killed product (107537). However, other clinical research in children ages 6 months to 12 years hospitalized with acute diarrhea shows that taking 15 billion heat-killed L. acidophilus (Lactrol, Raptakos) cells daily for 3 days along with oral rehydration solution (ORS) does not have beneficial effects on duration of diarrhea, frequency of stools, or length of hospital stay, when compared with ORS alone (111789). The European Society for Pediatric Infectious Diseases recommends probiotics in hospitalized children with diarrhea (98469) and the Infectious Disease Society of America (IDSA) recommends probiotics for the outpatient treatment of acute diarrhea (95388) However, L. acidophilus is not a specific focus of the guidelines and most evidence is low quality.
• Generalized anxiety disorder (GAD). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients newly diagnosed with GAD shows that taking sertraline 25 mg plus probiotics daily for 8 weeks may modestly reduce some symptoms of anxiety when compared with sertraline alone. However, the reduction in anxiety score was small and change was not consistent between rating scales. Also, the quality of life was not improved. The probiotics provided a total of 18 billion colony-forming units of L. acidophilus, Bifidobacterium bifidum, Bifidobacterium longum, and Bifidobacterium animalis subsp. lactis (110977).
• Hepatic encephalopathy. Although there has been interest in using oral Lactobacillus acidophilus for hepatic encephalopathy, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• HIV/AIDS. Although there has been interest in using oral Lactobacillus acidophilus for HIV/AIDS, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• Hypercholesterolemia. It is unclear if oral Lactobacillus acidophilus is beneficial for lowering cholesterol levels; the available research is conflicting. Details: Two meta-analyses of clinical research show that taking fermented milk products containing L. acidophilus can reduce total cholesterol by about 14-19 mg/dL in adults with or without hypercholesterolemia. However, the effect of L. acidophilus on both total and LDL cholesterol levels is conflicting from available research (95396,95397,95399). Clinical trials included in these meta-analyses evaluated patients with hypercholesterolemia, type 2 diabetes, nonalcoholic fatty liver disease (NAFLD), metabolic syndrome, and others. Taking L. acidophilus does not appear to improve high-density lipoprotein (HDL) cholesterol or triglyceride levels (95396,95397,95399). Doses used in some studies have included fermented milk products providing L. acidophilus 39 million to 2 billion CFUs daily, alone or along with other probiotic species, for up to 6 weeks (95396). One small clinical trial in patients with hypercholesterolemia shows that taking L. acidophilus LA-1 60 billion colony-forming units (CFUs) three times daily for 6 weeks does not affect serum lipids when compared with taking placebo (111791). A meta-analysis of nine small to moderate-sized clinical studies shows that taking a combination of L. acidophilus and Bifidobacterium animalis subsp. lactis reduces levels of total cholesterol when compared with placebo (107591). However, it is unclear if this is due to L. acidophilus, Bifidobacterium animalis subsp. lactis, or their combination.
• Hypertension. Although there has been interest in using oral Lactobacillus acidophilus for hypertension, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• Inflammatory bowel disease (IBD). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small preliminary clinical trial in patients with collagenous colitis shows that taking 10 billion colony-forming units each of L. acidophilus LA-5 and Bifidobacterium longum subsp. lactis BB-12 twice daily for 12 weeks does not increase the proportion of patients with a reduction in weekly bowel frequency of at least 50% when compared with placebo. Also, there was no effect of this combination on stool consistency or abdominal symptoms. However, there were some modest benefits when compared with baseline (110999). This study was small and may have been underpowered to detect differences.
• Intraventricular hemorrhage. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in premature infants shows that taking 6 billion CFUs of a combination of L. acidophilus NCDO 1748 and Bifidobacterium bifidum NCDO 2203 (UFC Inforan, Switzerland) from 7 days of age until 34 weeks postmenstrual age or discharge does not reduce the odds of intraventricular hemorrhage when compared with a control group of infants not given these probiotics. The infants in this study were born at less than 32 weeks gestation and had a birthweight of less than 1500 grams (111794). This study is limited by the lack of randomization to treatment group; placement was based on year of birth.
• Lactose intolerance. It is unclear if oral Lactobacillus acidophilus is beneficial for lactose intolerance. Details: One small clinical trial shows that consuming 400 mL of a non-fermented milk product containing L. acidophilus 530 million colony-forming units (CFUs)/mL daily does not reduce symptoms of lactose intolerance or hydrogen breath test results when compared with milk without L. acidophilus (16737). Another small preliminary clinical trial shows that taking L. acidophilus BG2FO4 10 billion CFUs twice daily for 7 days does not reduce lactose-induced gastrointestinal symptoms or improve lactose digestion based on breath hydrogen when compared with baseline (111783). However, another clinical trial shows that adding various L. acidophilus strains 800 million to 1 billion CFUs/mL to non-fermented milk improves hydrogen breath tests in patients with lactose intolerance (16738).
• Lyme disease. Although there has been interest in using oral Lactobacillus acidophilus for Lyme disease, there is insufficient reliable information about the clinical effects of L. acidophilus for this condition.
• Metabolic syndrome. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in elderly patients with metabolic syndrome shows that taking a combination of L. acidophilus PBS066-DSM 24,936, Lactiplantibacillus plantarum PBS067-DSM 24,937, and Limosilactobacillus reuteri PBS072-DSM 25,175 as 2 billion colony-forming units (CFUs) each, with inulin and fructo-oligosaccharides daily for 60 days, reduces the number of patients diagnosed with metabolic syndrome by 23%, compared with a 10% reduction in those taking placebo. In the probiotic group, there were modest improvements in waist circumference and levels of fasting plasma insulin, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, and inflammatory mediators when compared with placebo. However, there were no significant differences between groups for fasting blood glucose or blood pressure. All patients in this study were on a Mediterranean-like standard diet (107560).
• Necrotizing enterocolitis (NEC). It is unclear if oral Lactobacillus acidophilus is beneficial or safe for NEC prevention. Details: Most meta-analyses of clinical research show that giving lactobacilli enterally reduces the risk of NEC and/or severe NEC in preterm, mainly very low birth weight (VLBW), infants. Some meta-analyses support the use of lactobacilli in combination with bifidobacteria, as opposed to lactobacilli alone for reducing the risk of NEC. However, only a small number of the individual studies included in these analyses have investigated the effects of L. acidophilus, which was used as part of a combination probiotic and/or prebiotic product in all cases (95344,95351,103437,103445,104157,105162,105164). Also, guidance among regulatory agencies and clinical organizations varies with respect to the use of probiotics in very low birth weight infants under 1000 grams. The US Food and Drug Administration (FDA) warns that preterm infants given probiotics are at risk of serious infections caused by the bacteria or fungi contained in probiotics due to cases reported in this group of infants (111610). Also, The American Academy of Pediatrics does not support the routine administration of probiotics to preterm infants, particularly those with a birth weight below 1000 grams, due to conflicting data on safety and efficacy and potential for harm in this vulnerable population (111608). The Canadian Paediatric Society, the American Gastroenterological Association, and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition state that probiotic combinations may be of benefit in reducing the incidence of NEC in preterm neonates over 1000 grams. However, L. acidophilus is not specifically recommended (103003,111609,111611).
• Nonalcoholic fatty liver disease (NAFLD). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children with NAFLD, clinical research shows that taking a specific combination product (Prokid, Gostaresh Milad Pouya Company) containing L. acidophilus ATCC B3208 3 billion colony-forming units (CFUs), Lacticaseibacillus rhamnosus DSMZ 21690 2 billion CFUs, Bifidobacterium animalis subsp. lactis DSMZ 32269 6 billion CFUs, and Bifidobacterium bifidum ATCC SD6576 2 billion CFUs daily for 12 weeks normalizes liver sonography findings in 53% of children, compared with 17% of those taking placebo. In addition, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are reduced by 30% and 25%, respectively. There was no effect on body mass index or blood lipids when compared with placebo (105156). Another clinical trial shows that taking two sachets daily for 3 months of a specific combination product (VSL#3) containing L. acidophilus and other probiotics modestly decreases triglyceride levels and liver enzymes when compared with taking placebo. However, there was no change in body mass index or most glycemic or lipid parameters (111009). However, taking L. acidophilus in combination with other probiotics does not seem to be beneficial in adults with NAFLD. Clinical research shows that taking yogurt 100 grams, containing L. acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12 40 million CFUs and vitamin D 1000 IU, daily for 3 months does not improve fasting blood glucose levels, insulin levels, blood pressure, or anthropometric indices when compared with unfortified yogurt (105174). Also, a small clinical trial shows that taking a combination of L. acidophilus BCMC 12,130, Lacticaseibacillus casei BCMC 12,313, Lactobacillus delbrueckii subsp. lactis BCMC 12,451, Bifidobacterium bifidum BCMC 02290, Bifidobacterium longum subsp. infantis BCMC 02129, and Bifidobacterium longum BCMC 02120 30 billion colony-forming units twice daily for 6 months has no beneficial effects on hepatic steatosis or fibrosis or on levels of liver enzymes, blood lipids, or fasting glucose, when compared with placebo (107523).
• Nonalcoholic steatohepatitis (NASH). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with NASH shows that taking 1 billion colony-forming units each of L. acidophilus ATCC SD5221 and Bifidobacterium animalis subsp. lactis HN019 daily for 6 months does not have beneficial effects on severity of liver fibrosis or steatosis, metabolic markers, or inflammation when compared with taking placebo. The effect of this combination on liver enzymes was mixed (111797).
• Obesity. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In combination with Bifidobacterium animalis subsp. lactis BS01, taking L. acidophilus LA02 2 billion colony-forming units (CFUs) daily for 6 weeks does not reduce body weight or body fat when compared with placebo in young, healthy females, only some of whom were overweight (103438). However, another clinical study shows that taking 50 billion CFUs of a specific combination of L. acidophilus, Lactiplantibacillus plantarum, Bifidobacterium bifidum, and B. animalis subsp. lactis (Lab4P) for 24 weeks reduces body weight by an additional 1.3 kg more than placebo (103439).
• Polycystic ovary syndrome (PCOS). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In patients with PCOS, clinical research shows that taking a combination of L. acidophilus T16 (IBRC-M10785), Lacticaseibacillus casei T2 (IBRC-M10783), and Bifidobacterium bifidum T1 (IBRC-M10771) 2 billion colony-forming units each, plus inulin 800 mg, daily for 12 weeks modestly reduces serum insulin and triglyceride levels and improves insulin resistance and insulin sensitivity when compared with placebo. However, it does not alter cholesterol or fasting glucose levels (105159). Another clinical trial shows that 31.3% of patients with PCOS taking L. acidophilus in combination with other probiotics daily for 6 months had regular menstrual cycles compared with 12.5% of those taking placebo. There were also modest improvements in testosterone levels and waist circumference, but not other hormones, insulin resistance, body weight, or most measures of quality of life. The product provided Lactobacillus acidophilus UBLA-34 2 billion CFUs along with Bifidobacterium bifidum UBBB-55, Lactiplantibacillus plantarum UBLP-40, Lacticaseibacillus casei UBLC-42, Limosilactobacillus fermentum UBLF-31, Lacticaseibacillus rhamnosus UBLR-58, Limosilactobacillus reuteri UBLRu-87, and fructo-oligosaccharides (FOS) daily for 2 months and then twice daily for 4 months. All patients also underwent dietary and lifestyle changes (110974).
• Postoperative infection. Although there has been interest in using oral Lactobacillus acidophilus for preventing postoperative infections, there is insufficient reliable information about the clinical effects of lactobacillus for this purpose.
• Pouchitis. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Continuous oral treatment for one year with a specific concentrated formulation of L. acidophilus and other probiotics (Visbiome, ExeGi Pharma) as 6 grams (300-500 billion live bacteria per gram), daily for up 12 months seems to maintain remission of pouchitis in 85% of patients (6087,12769). Also, one small clinical study shows that taking a specific product (Trilac, Allergon AB) containing L. acidophilus 600 million colony-forming units (CFUs) per capsule, Lactobacillus delbrueckii subsp. bulgaricus 400 million CFUs per capsule, and Bifidobacterium bifidum 600 million CFUs per capsule, taken in doses of two capsules three times daily for 9 months, can reduce pouchitis severity and the number of patients experiencing pouchitis when compared to baseline (90296). The validity of these findings is limited by the lack of a comparator group.
• Pregnancy-induced nausea and vomiting. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small preliminary clinical trial shows that taking probiotics during pregnancy reduces the severity and duration of nausea and vomiting by 16% to 54%. There was also a small benefit on stool hardness. A specific probiotic (Probiotics 10, Nature's Bounty) was taken as 2 capsules daily for two back-to-back cycles of six days with probiotics and two days without. Each capsule contained a total of 10 billion colony-forming units (CFUs) of L. acidophilus La-14, Lactiplantibacillus plantarum 299v and DSM 15312, Lactobacillus delbrueckii subsp. bulgaricus Lb-87, Lacticaseibacillus paracasei DSM 13434 and Lpc-37, Ligilactobacillus salivarius Ls-33, Levilactobacillus brevis Lbr-35, Lacticaseibacillus casei Lc-11, and Bifidobacterium animalis subsp. lactis Bl-04, along with inulin 200 mg (107199).
• Prematurity. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In premature infants, clinical research shows that taking a blend of L. acidophilus, bifidobacteria, and Enterococcus faecalis (Peifeikang powder, Shanghai Xinyi Pharmaceutical Company), at least 5 million colony-forming units (CFUs) three times daily from birth until implementation of total parenteral nutrition, reduces the rate of development of extrauterine growth retardation from 15% to 8% when compared with those not receiving this blend (103448). Other preliminary clinical research in premature infants shows that taking 6 billion CFUs of a combination of L. acidophilus NCDO 1748 and Bifidobacterium bifidum NCDO 2203 (UFC Inforan, Switzerland) from 7 days of age until 34 weeks postmenstrual age or discharge reduces the odds of neurodevelopment impairment at 24 months corrected age by 70% when compared with a control group of infants not given these probiotics. The odds of having moderate to severe impairment were also reduced. The infants in this study were born at less than 32 weeks gestation and had a birthweight of less than 1500 grams (111794). This study is limited by the lack of randomization to treatment group; placement was based on year of birth. Observational research has also been conducted. One large observational study in infants fed strictly human milk, but not strictly formula or a combination, suggests that taking L. acidophilus 1 to 3 billion CFUs with Bifidobacterium longum subsp. infantis during the first month of life for the prevention of necrotizing enterocolitis was associated with a modest increased weight gain velocity. The infants in this study were born between 22-29 weeks gestation and had a birthweight of less than 1500 grams (111771).
• Psoriasis. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with psoriasis shows that taking a mixture of probiotics for 8 weeks modestly improves overall symptoms and feelings of depression when compared with placebo. The percentage of patients achieving at least a 50% or 75% reduction in overall symptom score was 40% and 24%, respectively, in those taking the probiotic mixture, compared with 16% and 8% of those taking placebo. Each probiotic capsule was used twice daily and provided a total daily dose of 2.6 billion colony-forming units (CFUs) of L. acidophilus, Bifidobacterium bifidum, Bifidobacterium animalis subsp. lactis, and Bifidobacterium longum (107498).
• Radiation-induced diarrhea. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with cervical cancer receiving radiotherapy with or without chemotherapy shows that taking a specific product (Biogurt, Fame Pharmaceuticals) containing L. acidophilus LA-5 and Bifidobacterium animalis subsp. lactis BB-12 as 1.75 billion lyophilized colony-forming units (CFUs) as a capsule three times daily throughout treatment reduces the risk of diarrhea by 28% when compared with placebo. The treatment group also used less loperamide (102285). Another small clinical trial in patients undergoing pelvic radiotherapy with weekly cisplatin shows that taking L. acidophilus and Bifidobacterium bifidum (Infloran, Laboratio Farmaceutico SIT) as 1 billion CFUs each, twice daily from seven days before starting radiotherapy and continuing during radiotherapy, reduces the incidence of moderate to severe diarrhea and the need for antidiarrheal medication when compared with placebo. Moderate to severe diarrhea occurred in 9% of patients using the probiotics, compared with 45% of those taking placebo (107580).
• Respiratory tract infections. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in children ages 3-5 years who attend daycare centers shows that taking a combination milk product containing 5 billion colony-forming units (CFUs) each of L. acidophilus and Bifidobacterium animalis (HOWARU Protect, Danisco) reduces the risk of experiencing fever, cough, and rhinorrhea by 45% when compared with placebo. Patients taking this combination experienced an average 2-day shorter duration of symptoms and were significantly less likely to use an antibiotic for their symptoms. Patients who took L. acidophilus without bifidobacterium also had a reduction in fever, cough, and use of antibiotics, but not rhinorrhea (16847). In healthy children aged 3-10 years, clinical research shows that taking 12.5 billion CFUs daily of a specific combination of L. acidophilus CUL21 and CUL60, Bifidobacterium bifidum CUL20, Bifidobacterium animalis subsp. lactis CUL34 (Lab4), and vitamin C 50 mg daily reduces the risk of cough by 16% and sore throat by 20%, and modestly reduces school absenteeism and antibiotic use when compared with placebo. However, nasal symptoms, fever, and wheezing were not reduced (106943). A different combination product containing L. acidophilus DDS-1 1 billion CFUs and B. animalis subsp. lactis UABLA-12 4 billion CFUs (Up4-Junior, UAS Laboratories) with fructo-oligosaccharides 50 mg has also been evaluated. Clinical research in children 3-12 years of age with a sick household member shows that taking this product daily for 2 weeks modestly shortens the duration of respiratory infections, but does not reduce the risk of developing an infection, when compared with placebo (98439). In overweight adults or adults with obesity, taking 50 billion CFUs of a specific combination of L. acidophilus, Lactiplantibacillus plantarum, B. bifidum, and B. animalis subsp. lactis (Lab4P) for 24 weeks reduces the overall likelihood of having upper respiratory tract infection symptoms, such as sneezing, cough, and blocked nose, by approximately 40% when compared with placebo (103439).
• Retinopathy of prematurity. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in premature infants shows that taking 6 billion CFUs of a combination of L. acidophilus NCDO 1748 and Bifidobacterium bifidum NCDO 2203 (UFC Inforan, Switzerland) from 7 days of age until 34 weeks postmenstrual age or discharge does not reduce the odds of retinopathy of prematurity when compared with a control group of infants not given these probiotics. The infants in this study were born at less than 32 weeks gestation and had a birthweight of less than 1500 grams (111794). This study is limited by the lack of randomization to treatment group; placement was based on year of birth. Also, one large observational study in premature infants suggests that taking L. acidophilus 1 to 3 billion CFUs with Bifidobacterium longum subsp. infantis during the first month of life for the prevention of necrotizing enterocolitis was not associated with a reduced risk of retinopathy of prematurity. The infants in this study were born between 22-29 weeks gestation and had a birthweight of less than 1500 grams (111771).
• Rheumatoid arthritis (RA). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with moderate-to-severe RA shows that taking capsules containing freeze-dried strains of L. acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum daily for 8 weeks does not improve RA severity, the number of tender or swollen joints, or joint pain when compared with placebo (95418).
• Rotaviral diarrhea. It is unclear if oral Lactobacillus acidophilus is beneficial for rotaviral diarrhea. Details: One preliminary clinical study shows that taking a combination of L. acidophilus AD031 2 billion colony-forming units (CFUs) and Bifidobacterium longum BORI 20 billion CFUs twice daily for 3 days reduces the duration of rotaviral diarrhea by an average of 3 days when compared with placebo (95334). However, one clinical study using a lower dose and different strain of L. acidophilus (La-14) 200 million CFUs twice daily for 5 days shows that this regimen does not reduce the duration of watery diarrhea or affect the viral load in children aged 9 months to 5 years with confirmed norovirus or rotavirus infection (96887). A small clinical study shows that heat-killed L. acidophilus LB 20-30 billion cells daily for up to 4 days can modestly reduce the duration of diarrhea in infants and children, some of which had confirmed rotavirus (90295).
• Sepsis. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in premature infants shows that taking 6 billion CFUs of a combination of L. acidophilus NCDO 1748 with Bifidobacterium bifidum NCDO 2203 (UFC Inforan, Switzerland) from 7 days of age until 34 weeks postmenstrual age or discharge reduces the odds of late onset sepsis by 55% when compared with a control group of infants not given these probiotics. The infants in this study were born at less than 32 weeks gestation and had a birthweight of less than 1500 grams (111794). This study is limited by the lack of randomization to treatment group; placement was based on year of birth. One large observational study in infants fed a mix of human milk and formula, but not strictly human milk or formula, suggests that taking L. acidophilus 1 to 3 billion CFUs with Bifidobacterium longum subsp. infantis during the first month of life for the prevention of necrotizing enterocolitis was associated with a 31% reduction in the development of clinical sepsis. The infants in this study were born between 22-29 weeks gestation and had a birthweight of less than 1500 grams (111771).
• Short bowel syndrome. Although there has been interest in using oral Lactobacillus acidophilus for short bowel syndrome, there is insufficient reliable information about the clinical effects of lactobacillus for this condition.
• Small intestinal bacterial overgrowth (SIBO). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children with chronic diarrhea due to SIBO shows that taking a combination of lyophilized L. acidophilus 1.5 grams and Lacticaseibacillus casei 1.5 grams by mouth twice daily for 21 days decreases average daily stools by 1.5, but does not improve other symptoms, when compared with placebo (91143). Also, one preliminary clinical study shows that taking a total of 2 billion CFUs of L. acidophilus and Lacticaseibacillus rhamnosus (Lacidofil) daily for 4 weeks does not prevent the development of SIBO in children that started treatment with omeprazole 20 mg daily for epigastric pain (90262).
• Travelers' diarrhea. It is unclear if oral Lactobacillus acidophilus is beneficial for the prevention of travelers' diarrhea. Details: A meta-analysis which included three clinical studies evaluating the use of L. acidophilus in adults traveling to different parts of the world found no benefit for the prevention of travelers' diarrhea when compared with placebo (101445). The effectiveness of this species may vary significantly based upon the destination of travel. Destinations in the same country can have different results, probably due to differences in bacteria and other microorganisms at different locations (10216).
• Ulcerative colitis. Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: The best evidence of benefit is for a specific combination product (Visbiome, ExeGi Pharma). Doses of 3 grams (equivalent to 900 billion colony-forming units (CFUs)) once or twice daily have been used in combination with conventional treatment. In children aged 1-16 years, doses of 450-1800 billion CFUs for up to one year have been used (3261,14370,14371,16841,95337). A meta-analysis of clinical research shows that taking this product as an adjunct to standard ulcerative colitis treatment can increase remission rates in adults and children by about 1.7-fold when compared with standard treatment alone (95337). Preliminary clinical research in patients with moderate to severe symptoms taking mesalazine 1200 mg daily shows that taking an unknown dose of L. acidophilus twice daily along with Bifidobacterium bifidum BGN4 and Ligilactobacillus salivarius (Acronelle, Bromatech srl, Milan, Italy) for 2 years modestly improves patient- and physician-scales of overall symptoms when compared with taking mesalazine alone. There were also improvements in stool frequency and rectal bleeding (110981). Although some contradictory evidence exists (3261,16841), most research shows that taking Visbiome or a combination of L. acidophilus LA-5 and Bifidobacterium animalis subsp. lactis BB-12 (Probio-Tec AB-25) does not prevent relapse in people who are already in remission (95337,95338).
• Urinary tract infections (UTIs). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In children aged 4 months to 5 years with a previous UTI, clinical research shows that taking a specific combination of L. acidophilus, Lacticaseibacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium animalis subsp. lactis (Complete Probiotic Platinum) for 18 months increases the median time to the first incidence of recurrence by approximately 3 months and increases the percentage of children without a UTI during the study period from 83% to 97% (103436).
• Vaginal candidiasis. It is unclear if oral or intravaginal Lactobacillus acidophilus is beneficial for vaginal candidiasis. Details: In a small preliminary clinical trial in patients with recurrent vulvovaginal candidiasis who had undergone a week of oral fluconazole treatment followed by intravaginal L. acidophilus LA 02 and Limosilactobacillus fermentum LF10, 72.4% of patients demonstrated a lack of clinical recurrence over a 7 month observational period. All patients took fluconazole 200 mg three times in the first week followed by intravaginal application with at least 0.4 billion colony-forming units each of L. acidophilus LA 02 and Limosilactobacillus fermentum LF10, along with arabinogalactan and fructo-oligosaccharides (FOS) on alternate days for 10 days and then once weekly for 10 weeks (111781). However, a combination of L. acidophilus, Lacticaseibacillus rhamnosus, Lactobacillus delbrueckii, and Streptococcus thermophilus (Femilac) given intravaginally, does not seem to reduce the risk of vaginal candidiasis infection following use of antibiotics (12108). There is also some evidence that eating yogurt enriched with L. acidophilus daily does not reduce the risk of recurrent vaginal candidiasis (1245).
• Ventilator-associated pneumonia (VAP). Oral Lactobacillus acidophilus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking L. acidophilus LA-5 1.75 billion colony-forming units (CFUs), Lactiplantibacillus plantarum 500 million CFUs, Bifidobacterium animalis subsp. lactis BB12 1.75 billion CFUs, and Saccharomyces boulardii 1.5 billion CFUs twice daily for 15 days reduces the risk of VAP to 12%, compared with 28% in those taking placebo. Half of the dose was given onto the oropharynx and half via a nasogastric tube (107524). More evidence is needed to rate Lactobacillus acidophilus for these uses.

(Read more about LACTOBACILLUS ACIDOPHILUS)

EFFECTIVE

• Bowel preparation. Various magnesium salts are used for cleansing the bowel prior to procedures such as colonoscopy. Details: Various magnesium salts, including citrate, hydroxide, oxide, and sulfate, are ingredients in bowel preparation products available over-the-counter or by prescription only.
• Constipation. Magnesium salts are effective when used short-term orally to treat constipation and chronic idiopathic constipation (CIC). Details: Magnesium citrate, hydroxide, oxide, and sulfate salts are commonly used as laxatives. Magnesium citrate 11.3-17.45 grams has been used; magnesium hydroxide 2.4-4.8 grams, as 30-60 mL of milk of magnesia, has also been used (113483,113484). Magnesium sulfate, also known as Epsom salt, which seems to have the most potent effect, has been used as 10-30 grams (6430,113485). Magnesium salts should only be used for occasional treatment of constipation, and doses should be taken with a full 8-ounce glass of water. Magnesium oxide seems to be beneficial in adults with CIC when taken short-term. Clinical guidelines published by the American Gastroenterology Association and American College of Gastroenterology in 2023 give a conditional recommendation suggesting the use of magnesium oxide over managing CIC without magnesium oxide based on low-quality studies conducted over 4 weeks. The recommended starting dose is 400-500 mg daily with dose titration per symptom response and side effects (112859). A small clinical study in patients with CIC who are not taking chronic medications shows that taking magnesium oxide 1.5 grams in three divided doses daily for 28 days increases spontaneous bowel movements when compared with placebo (104397). It is unknown if magnesium is beneficial for CIC when used long-term.
• Dyspepsia. Magnesium salts are effective when used orally as antacids. Details: Magnesium carbonate, hydroxide, oxide, or trisilicate salts are used orally as antacids to reduce symptoms of gastric hyperacidity or gastroesophageal reflux. Magnesium hydroxide has the fastest onset of action. The onset for magnesium carbonate is slower due to its crystal structure. Magnesium trisilicate has the slowest onset and longest duration of action due to poor solubility (6844). Doses used include magnesium hydroxide 400-1200 mg (5-15 mL of milk of magnesia) up to four times daily, or magnesium oxide 800 mg daily (15).
• Eclampsia. Magnesium sulfate is considered the drug of choice for control of seizures. Details: Intravenous (IV) and/or intramuscular (IM) magnesium sulfate is considered the agent of choice for seizure prophylaxis during eclampsia by the American College of Obstetricians and Gynecologists (ACOG) (15,12591,12592,61012,61184). Typical doses include 4-6 grams of magnesium sulfate by IV infusion in 250 mL of dextrose 5% or normal saline solution, followed by 4-5 grams of magnesium sulfate IM every 4 hours, or 1-3 grams per hour by continuous IV infusion. Doses should be adjusted according to serum levels and urinary excretion, and should not exceed 30-40 grams of magnesium sulfate daily (15,12591). Meta-analyses of clinical research show that treatment with IV or IM magnesium reduces the risk of seizure recurrence by 33% to 69% when compared with phenytoin, and by 47% to 60% when compared with diazepam (19960,60818,60954,60964,61105). One preliminary clinical study shows that lower doses of IV magnesium sulfate (9 grams loading dose and maintenance of 2.5 grams every 4 hours for 24 hours) are as effective as higher doses (14 grams loading dose and maintenance of 5 grams every 4 hours for 24 hours) for reducing the recurrence of eclamptic seizures (89383). It is generally recommended that treatment be continued for at least 24 hours after the last seizure (15). Oral magnesium has not been evaluated for eclampsia.
• Hypomagnesemia. Hypomagnesemia can be effectively treated with oral or parenteral magnesium. Details: Taking magnesium orally or parenterally is helpful for treating and preventing hypomagnesemia associated with alcoholism, cirrhosis of the liver, congestive heart failure (CHF), severe or prolonged diarrhea or vomiting, kidney dysfunction, inflammatory bowel disease (IBD), pancreatitis, malabsorption syndromes, and other conditions (6280,6281,8088,8089). The dose and salt of magnesium for oral replacement therapy should be chosen carefully to avoid causing diarrhea. The gluconate and chloride salts cause less diarrhea, while the oxide salt is more likely to cause diarrhea and should be avoided. Magnesium chloride should also be avoided due to poor solubility which decreases absorption (6430,8099,10664). Orally, magnesium sulfate 3 grams every 6 hours for four doses has been used for hypomagnesemia (15). Parenteral magnesium doses must be individualized according to serum magnesium levels, but a typical starting dose for mild deficiency is 1 gram of magnesium sulfate intramuscularly (IM) every 6 hours for 4 doses (15). For more severe deficiency, 5 grams of magnesium sulfate may be given as an intravenous (IV) infusion in 1 liter of dextrose 5% or normal saline solution over 3 hours (15).
• Pre-eclampsia. Magnesium sulfate is considered the drug of choice for seizure prophylaxis in patients with pre-eclampsia. Details: Intravenous (IV) and/or intramuscular (IM) magnesium sulfate is considered the agent of choice for seizure prophylaxis during pre-eclampsia by the American College of Obstetricians and Gynecologists (ACOG) (12591,12592,61012,61184). Some meta-analyses show that IV administration of magnesium sulfate reduces the risk of eclampsia when compared with placebo, phenytoin, or diazepam in patients with pre-eclampsia (19960,60818,60960,60979). A typical initial dose is 4-5 grams of magnesium sulfate by IV infusion in 250 mL of dextrose 5% or normal saline solution, followed by 4-5 grams of magnesium sulfate IM every 4 hours, or 1-3 grams of magnesium sulfate per hour by continuous IV infusion. Doses should be adjusted according to serum levels and urinary excretion, and should not exceed 30-40 grams of magnesium sulfate daily (15,12591). The optimal duration of prophylaxis has not been determined. A meta-analysis suggests that using a shorter duration of 12 hours or less is not associated with an increase in risk of eclamptic seizures when compared with regimens of 24 hours or longer (108732). However, studies are likely underpowered due to the low incidence of eclampsia. Oral magnesium has been evaluated for the prevention of pre-eclampsia in healthy adults, but taking magnesium citrate 300 mg daily, starting at 12-20 weeks' gestation and continuing until delivery, does not reduce the incidence of pre-eclampsia when compared with placebo (103724).

LIKELY EFFECTIVE

• Cerebral palsy. Most evidence shows that antenatal magnesium reduces the risk of cerebral palsy in preterm infants, although there are some inconsistent results. Details: Most clinical studies and meta-analyses show that antenatal magnesium sulfate reduces the risk of cerebral palsy by about 32% and the risk of motor dysfunction by about 45% in preterm infants (60915,60927,60931,61001,97485,103734,103754,114675,114681). The lowest effective dose of magnesium sulfate seems to be 4 grams intravenously, with or without a maintenance dose of 1 gram/hour until birth or for 24 hours. In obese females, a higher dose, based on body weight, may be needed (97485,97495,103734,103754). However, some studies have inconsistent results (8093,19998,98293,98295,112784). Giving females at risk of imminent preterm birth (prior to 32 weeks), intravenous magnesium sulfate 4.5 grams over 20 minutes followed by 1 gram per hour until birth or for 24 hours, in addition to a standard treatment protocol, does not reduce the incidence of cerebral palsy (112784). Oral magnesium has not been evaluated for this purpose.
• Seizures. Intravenous magnesium sulfate is used for treating seizures of various etiologies. Details: Intravenous magnesium sulfate may be useful for controlling seizures associated with epilepsy, glomerulonephritis, hypothyroidism, and acute nephritis in children (15). Oral magnesium has not been evaluated for this purpose.
• Torsades de pointes. Intravenous magnesium sulfate is the first-line treatment for torsades de pointes after measures to correct precipitating factors have been unsuccessful. Details: Intravenous magnesium sulfate has been used successfully to treat the life-threatening ventricular tachycardia, torsades de pointes (15,6844). The Advanced Cardiac Life Support (ACLS) guidelines of the American Heart Association recommend a dose of 1 to 2 grams diluted in 50-100 mL Dextrose 5% solution given IV over 5-60 minutes, followed by a continuous IV infusion of 0.5-1 gram/hour.

POSSIBLY EFFECTIVE

• Arrhythmia. Magnesium sulfate is effective for the specific type of ventricular tachycardia known as torsades de pointes, and seems to be helpful for treating other types of arrhythmias. Evidence for the role of oral or intravenous magnesium in preventing postoperative arrhythmias is conflicting. Details: Administering magnesium intravenously or orally may be helpful for treating atrial and ventricular tachycardia and fibrillation, and supraventricular tachycardia (9497,13352,13354,13355,13356,60804,60829,60877,61113,111696). Arrhythmias associated with congestive heart failure have been treated with magnesium sulfate 8 grams infused over 12 hours (9497). For rate control in atrial fibrillation, magnesium sulfate 2.5 grams IV over 20 minutes, followed by 2.5 grams IV over 2 hours has been used (13356). For paroxysmal supraventricular tachycardia, single doses of 1-4 grams of magnesium chloride have been used (13352). For atrial tachycardia, 2 grams of magnesium sulfate in 10 mL of dextrose 5% solution has been given IV over 1-10 minutes, followed by 5-10 grams of magnesium sulfate in 250-500 mL dextrose 5% solution as an IV infusion over 5 hours (13354,13355). Research on the effects of intravenous magnesium for preventing arrhythmias after cardiac surgery is conflicting. Some meta-analyses show that intravenous magnesium reduces the risk of atrial fibrillation, ventricular arrhythmias, or supraventricular arrhythmias following cardiac surgery by 23% to 48% when compared with placebo (60814,60826,60828,60838,61008,61033,61181,97487,97490). Doses of magnesium sulfate used include 30 mg/kg in 500 mL normal saline (97490), or 80-100 mg/kg added to the cardioplegia solution (97487). Also, one small study in adults after CABG surgery suggests that taking magnesium hydroxide 1600 mg orally reduces arrhythmia as effectively as receiving magnesium sulfate 2000 mg intravenously (99315). However, other meta-analyses that only include higher-quality trials show that magnesium supplementation does not reduce the risk of ventricular or supraventricular arrhythmias following cardiac surgery (61010,61024,61031,105081). A meta-analysis of clinical trials of intravenous magnesium for prevention of new-onset atrial fibrillation after non-cardiac surgeries shows that it does not reduce the incidence significantly when compared with placebo (112778). However, there was a high risk of bias in the analysis, and variability in types of surgery, and the salt and dose of magnesium used.
• Asthma. Parenteral magnesium sulfate can help to reverse severe acute asthma attacks and reduce the need for hospital admission. It is unclear if nebulized magnesium is beneficial for acute asthma attacks. However, oral magnesium does not seem to be beneficial. Details: Overall, a single dose of intravenous magnesium seems to improve pulmonary function in acute asthma exacerbation and reduce the risk of hospitalization, particularly in patients with severe asthma, and those who have failed initial treatment with nebulized albuterol and intravenous corticosteroids (60888,90023,96483,104398,107365). The typical dose used for adults is 2 grams of magnesium sulfate infused over 20 minutes (15). For children, 25-75 mg/kg, to a maximum of 2 grams, infused over 20-30 minutes has been used (15,96483,107365). However, a post-hoc analysis of one large clinical trial (104400) designed to assess nebulized magnesium in children with acute asthma has found that adding IV magnesium to nebulized magnesium is associated with greater odds of hospitalization when compared with no IV magnesium (105919). This post-hoc analysis did not differentiate between precautionary and necessary hospitalizations. Although some clinical research and a meta-analysis in patients with acute asthma exacerbation show that nebulized magnesium in combination with standard treatment improves airway function, respiratory rate, and clinical asthma severity when compared with standard treatment alone, it is unclear whether these findings are clinically relevant (90016,113466). Most evidence, including larger clinical trials and meta-analyses, has not shown benefit of adjunct nebulized magnesium for acute asthma in adults or children (60888,90002,96484,104400,105920,113466,114674). Oral magnesium also does not seem to be beneficial. A meta-analysis of small clinical trials in children and adults with asthma shows that taking magnesium supplements orally does not improve lung function or reduce bronchodilator use when compared with control (104404).
• Colorectal cancer. Increasing dietary magnesium intake seems to lower the risk of colon cancer but not rectal cancer. Details: Epidemiological research shows that increased dietary magnesium intake is associated with a reduced risk of colon cancer, but the risk of rectal cancer is not affected (89387,90017,90027,101355).
• Diabetes. Low dietary magnesium may increase the risk of developing type 2 diabetes, but evidence on the use of supplements for treating type 2 diabetes is conflicting. Details: Higher dietary magnesium intake is associated with lower fasting insulin concentrations and a reduced risk of developing type 2 diabetes in adults and obese children (13369,15548,96473,97486,98294,103736,105918,106920). In people with existing type 2 diabetes, hypomagnesemia is found in 25% to 38% of patients, especially in those with poorly controlled diabetes (1172). Population research in adults with type 2 diabetes also shows that a dietary magnesium intake of less than 250 mg daily is associated with a 56% higher risk of mortality. Preliminary subgroup analyses suggest that the risk of mortality is higher in those with glycated hemoglobin (HbA1C) levels above 7% (110051). A meta-analysis of small, heterogeneous clinical studies in adults with type 2 diabetes suggests that magnesium may modestly reduce HbA1C in patients with hypomagnesemia, but not in patients with normal magnesium levels, when compared with control (105075). Individual clinical studies using magnesium supplements in patients with type 2 diabetes or insulin resistance have shown mixed results. Some research suggests magnesium supplements can decrease fasting blood glucose and improve insulin sensitivity, as well as reduce the risk of developing diabetes in high-risk patients (10664,12582,13376,60854,99313,106920), but other research shows no effect (1171,1172,13379,13380,112780). Discrepancies in these findings might reflect differences in magnesium salts and doses used, or differences in baseline magnesium status in study subjects.
• Hypercholesterolemia. Magnesium may help improve lipid levels by a small amount in people with this condition. Details: There is some evidence that taking magnesium oxide 1 gram orally daily for 6 weeks can produce small decreases in low-density lipoprotein (LDL) and total cholesterol levels, and small increases in high-density lipoprotein (HDL) levels in patients with hypercholesterolemia. However, magnesium does not seem to improve lipoprotein (a) levels (1193). Magnesium may also lower triglycerides in people with hypertriglyceridemia (97494).
• Metabolic syndrome. Low dietary and serum levels of magnesium seem to be associated with the development of metabolic syndrome. Details: Higher magnesium intake from diet and supplements is associated with a 27% lower risk of developing metabolic syndrome in healthy females (13371) and a 31% lower risk in healthy young adults (14304). Additional epidemiological research suggests that people with low serum magnesium levels are 6-7 times more likely to have metabolic syndrome than people with normal magnesium levels (13372). In a population analysis of over 6000 individuals without metabolic syndrome at baseline, the risk of developing this condition over a 6-year follow-up period was reduced by 16% in the highest quintile of dietary magnesium intake (median intake 371 mg daily) when compared with the lowest quintile (median intake 203 mg daily). Some, but not all, research suggests that the hazard ratio for metabolic syndrome in relation to magnesium intake may be U-shaped, with higher risk at intakes below about 150 mg daily and above 600 mg daily (108963). A combination of magnesium 20 mEq daily and potassium 40 mEq daily (magnesium potassium citrate) taken orally for 16 weeks reverses metabolic side effects of chlorthalidone, such as increased fasting plasma glucose and hypokalemia, more effectively than potassium chloride 40 mEq daily alone (112932).
• Osteoporosis. Increased dietary and supplemental magnesium intake seems to increase bone mineral density and decrease bone loss in postmenopausal patients. Details: Preliminary clinical research shows that taking magnesium hydroxide orally, 300-1800 mg daily for 6 months, then 600 mg daily for 18 months, or magnesium citrate orally 1830 mg daily for 30 days, might reduce bone loss and bone turnover in postmenopausal patients with osteoporosis (9104,60928). Some epidemiological research also suggests that magnesium intake is related to increased bone mineral density (12501,12502,12503,12504,90014), although not all studies have found an association (12505,98286).
• Postoperative pain. Injectable magnesium has been used with promising results for reducing pain and the need for other analgesics postoperatively. Details: A meta-analysis of 25 clinical trials shows that intravenous (IV) magnesium sulfate, 5-50 mg/kg bolus followed by a continuous infusion of 6 mg/kg or 500 mg hourly during surgery, seems to reduce the 24-hour postoperative use of IV morphine by 24% when compared with placebo (19968). Adding IV magnesium sulfate 3.7-5.5 grams to patient-controlled analgesia for 24 hours after surgery has also been used (19968). Additionally, meta-analyses support that adjunctive IV or intrathecal administration of magnesium reduces post-operative pain scores, improves pain relief and sensory nerve block, and decreases the need for other analgesics, when compared with control (89390,90012,90015,98287,103728,114676,114677,114678). However, some data are conflicting. In a meta-analysis of 7 trials, IV magnesium was not associated with lower pain scores over the first 48 hours postoperatively. The reasons for these discrepant findings are unclear but may be explained by differences in magnesium regimens, anesthesia protocols, and surgical populations studied. Additionally, IV magnesium appears to be less effective than dexmedetomidine (105082). Two moderate-sized clinical studies in patients undergoing total knee arthroplasty in China show that adding magnesium sulfate 2.5 mg/mL to the periarticular infiltration analgesia (PIA) cocktail or administering IV magnesium sulfate 40 mg/kg before anesthesia induction then as a 15 mg/kg infusion during surgery reduces pain scores, increases comfort levels, limits and delays the use of postoperative opioids, prolongs analgesia, and reduces markers of inflammation when compared with the usual PIA cocktail or control (111181,113677). Administering magnesium intravenously also seems to be helpful for pain control after hysterectomy. A 3-gram IV bolus of magnesium sulfate followed by an infusion of 0.5 grams per hour for 20 hours has been used. Lower doses were not effective (6848). In males undergoing laparoscopic radical resection for gastrointestinal cancer, administering IV magnesium intraoperatively, as a loading dose of 40 mg/kg followed by 15 mg/kg/hour through the end of surgery, reduces postoperative catheter-related bladder discomfort and analgesic requirements, when compared with placebo (112783). However, IV magnesium might not alleviate postoperative pain in children. Two small clinical studies show that administering a magnesium IV infusion does not reduce pain when compared with saline in children after tonsillectomy or after elective strabismus surgery (98282,105077).
• Premenstrual syndrome (PMS). Taking magnesium orally seems to relieve symptoms of PMS. Details: There is some evidence that magnesium supplementation can improve symptoms, including mood changes and fluid retention, in some patients with PMS (1187,1188,6847). Doses used include magnesium oxide 333 mg daily for 2 menstrual cycles, or magnesium pyrrolidone carboxylic acid equivalent to 360 mg elemental magnesium three times daily, from the 15th day of the menstrual cycle until onset of menstrual flow (1187,1188). Taking magnesium orally in a dose of 360 mg (elemental magnesium) three times daily for 2 months seems to prevent premenstrual migraine (1186,6847). A combination of magnesium 200 mg daily plus vitamin B6 50 mg daily seems to reduce anxiety-related premenstrual symptoms, including nervous tension, mood swings, irritability, and anxiety, when compared with placebo (8555).
• Vasospastic angina. Intravenous magnesium seems to prevent coronary spasm in patients with this condition. Details: Clinical research shows that administration of intravenous magnesium sulfate 65 mg/kg infused over 20 minutes dilates coronary arteries and suppresses acetylcholine-induced coronary spasms when compared with infusion of a dextrose solution in patients with vasospastic angina (8091).

POSSIBLY INEFFECTIVE

• Altitude sickness. Taking magnesium citrate orally does not seem to reduce acute altitude sickness risk. Details: Clinical research shows that taking magnesium citrate 1200 mg daily orally in three divided doses, beginning 3 days prior to mountain ascent and continuing until mountain descent, does not reduce the risk of acute altitude sickness when compared with placebo (60801).
• Athletic performance. Taking magnesium orally does not seem to improve energy or endurance during athletic activity. Details: Most evidence suggests that taking magnesium orally doesn't increase energy and endurance during athletic activity. Magnesium oxide, aspartate, and orotate salts do not seem to improve exercise performance when used alone or in combination with potassium, vitamin B6, or zinc (2825,2826,2828,2829,2830,60751,113655).
• Bronchiolitis. Intravenous or nebulized magnesium is not beneficial in infants with this condition. Details: Clinical research shows that administering a single IV dose of magnesium sulfate 100 mg/kg to infants with acute bronchiolitis does not improve, and may actually worsen, symptoms when compared with placebo (97482). A clinical study in infants with moderate to severe bronchiolitis shows that adding nebulized magnesium sulfate 40 mg/kg to nebulized epinephrine does not reduce hospital stay or the need for ventilator or oxygen support when compared with epinephrine alone (99317). Oral magnesium has not been evaluated for this use.
• Chemotherapy-induced peripheral neuropathy. Research on the effects of intravenous infusions of magnesium and calcium for preventing oxaliplatin neurotoxicity are inconsistent, but higher quality studies seem to show no benefit. Details: Pooled analyses of cohort studies and clinical trials show that calcium and magnesium infusions can decrease the incidence of severe oxaliplatin-induced neurotoxicity (90028,90029,90031). However, when only clinical trials are considered, the infusions do not appear to be helpful (90005,90029,90031,96474,96479).
• Complex regional pain syndrome. Intravenous magnesium is not beneficial in complex regional pain syndrome type 1. Details: Clinical research shows that receiving magnesium sulfate 70 mg/kg intravenously at the rate of 25 mL/hour for 4 hours each day for 5 days does not improve pain or level of impairment when compared with placebo in patients with chronic complex regional pain syndrome type 1 (89395).
• Emergence delirium. The majority of small clinical studies in adults and children undergoing various surgeries suggest that intravenous (IV) magnesium doesn't reduce the risk of emergence delirium. However, most clinical studies in adults suggest that IV magnesium reduces emergence agitation. Details: A small clinical study in adults undergoing surgery for endovascular aortic aneurysm repair shows that administering IV magnesium 30 mg/kg as a loading dose, followed by a 10 mg/kg/hour infusion for the duration of surgery, does not improve agitation or delirium scores when compared with administering saline (111182). Similarly, a small clinical study in children ages 2-5 years undergoing elective strabismus surgery shows that administering IV magnesium during anesthesia does not seem to prevent the occurrence of emergence delirium when compared with administering saline (105077). In a meta-analysis of 8 clinical trials in children aged 2-16 years undergoing general anesthesia for oral or ophthalmic surgery, giving IV magnesium as a 30 mg/kg loading dose followed by a 10 mg/kg/hour infusion, or as a single dose of 15-30 mg/kg, does not reduce emergence delirium scores, and may actually prolong emergence times (108729). However, there is some conflicting evidence. In patients undergoing radical mastectomy, giving intraoperative magnesium sulfate 30mg/kg over 1 hour, followed by 10 mg/kg/hour until the end of surgery, reduces emergence agitation (odds ratio 0.26) when compared with placebo (112781).
• Menopausal symptoms. Oral magnesium oxide does not seem to be beneficial for menopausal hot flashes. Details: A small, low quality study in postmenopausal patients with a history of breast cancer shows that taking magnesium oxide 400-800 mg orally daily reduces hot flashes when compared with baseline (102454). However, a larger, higher quality clinical study using magnesium oxide 800-1200 mg daily did not show any benefit when compared with placebo (98290).
• Muscle cramps. Oral magnesium does not seem to improve muscle cramp frequency or intensity. Details: Meta-analyses of small clinical trials show that magnesium supplementation for 3-6 weeks does not decrease the frequency or intensity of skeletal muscle cramps, whether the cramps are idiopathic or due to liver cirrhosis or pregnancy, when compared with placebo (90022,104395).
• Sickle cell disease. Intravenous magnesium does not add any benefit to standard therapy for sickle cell disease in children. Details: Clinical research shows that giving magnesium sulfate 40-100 mg/kg (maximum of 2 grams per dose) intravenously every hour for 6-8 doses as an adjunct to standard therapy does not decrease hospital stay, pain, or opioid use, or improve quality of life, when compared with standard therapy and placebo in children with sickle cell disease (89399,98283,101356). Oral magnesium has not been evaluated for this purpose.
• Stillbirth. Magnesium administered during pregnancy does not reduce stillbirth risk. Details: A meta-analysis of clinical research shows that magnesium supplementation does not significantly decrease the risk of stillbirths when administered during pregnancy (60925,60978).
• Tetanus. Intravenous magnesium sulfate does not seem to improve outcomes in patients with this condition. Details: A meta-analysis of clinical research shows that intravenous magnesium sulfate does not reduce mortality when compared with placebo or diazepam in patients with tetanus (61020). While some research shows that magnesium reduces the duration of hospitalization and the need for ventilation when compared with diazepam (61170), magnesium does not seem to improve these outcomes when compared with placebo (60860).
• Traumatic brain injury (TBI). Magnesium does not improve clinical outcomes in patients with moderate to severe TBI. Its effect in patients with concussions is unclear. Details: A meta-analysis of four clinical trials shows that treatment with magnesium does not significantly improve neurological outcomes or reduce the risk of mortality when compared with placebo in patients with moderate to severe TBI (60905). A small observational cohort study in adolescents with concussions has found that adding oral magnesium 400 mg twice daily for 5 days to standard treatment with acetaminophen and ondansetron is associated with a trend toward reduced symptom severity when compared with standard treatment alone (104401). The validity of this study is limited by its observational nature and small cohort size.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. Intravenous magnesium does not seem to help reduce symptoms of alcohol withdrawal but may reduce the duration of alcoholic delirium. Details: Preliminary clinical research shows that administration of four intramuscular injections of magnesium sulfate 2 grams at 6-hour intervals does not reduce symptoms of alcohol withdrawal when compared with saline (61063). A small observational study in patients with alcoholic delirium has found that administering magnesium sulfate IV 50 mg/kg every 8 hours, in addition to usual sedation, is associated with a reduction of delirium by approximately 2 days, or 4 days when given every 12 hours in addition to dexmedetomidine, when compared with usual sedation alone (111180). However, half of patients had hypomagnesemia at baseline; it is unclear if effects would be similar for patients with normal magnesium levels. Oral magnesium has not been evaluated for this purpose.
• Allergic rhinitis (hay fever). Although there has been interest in using oral magnesium for allergic rhinitis, there is insufficient reliable information about the clinical effects of magnesium for this purpose.
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral magnesium is beneficial in children with ADHD. Details: Children with ADHD seem to have lower magnesium levels in their blood and hair (9969,100262,100263). A small clinical study in children aged 7-12 years with ADHD and magnesium deficiency shows that taking magnesium aspartate and lactate 6 mg/kg daily for 6 months might improve hyperactivity and magnesium levels when compared with control (1189). Another small clinical study in children with ADHD but without magnesium deficiency shows that taking magnesium 6 mg/kg daily along with vitamin D 50,000 IU weekly for 8 weeks may modestly improve emotional problems, but not inattention or hyperactivity, as measured on the strength and difficulties questionnaire (SDQ), when compared with placebo (105914).
• Back pain. It is unclear if oral or intravenous magnesium is beneficial for acute or chronic back pain in adults. Details: One open-label clinical study in adults with acute low-back pain shows that taking magnesium 365 mg once daily in addition to taking etodolac 400 mg twice daily for 10 days does not further reduce pain when compared with taking etodolac alone (105913). Magnesium has also been tried for chronic back pain. A small clinical study in patients with chronic low-back pain shows that receiving magnesium sulfate 1 gram in 250 mL normal saline intravenously every 4 hours for 2 weeks, followed by magnesium gluconate 100 mg and magnesium oxide 400 mg by mouth daily for 4 weeks, reduces pain severity when compared with placebo (90035). It is unclear if oral magnesium used alone is beneficial.
• Bariatric surgery complications. It is unclear if oral magnesium supplementation improves metabolic parameters after bariatric surgery. Details: A retrospective study of over 3000 post-bariatric surgery patients suggests that those who take oral magnesium supplements providing 100-450 mg elemental magnesium daily may have improved metabolic parameters over 4 years of follow-up. When patients taking magnesium supplements were compared with those not taking supplements, 11% and 18% had type 2 diabetes, respectively, 30% and 42% had hypertension, respectively, and 16% and 23% had elevated low-density lipoprotein (LDL) cholesterol levels, respectively. For patients with hypomagnesemia at baseline, supplementation seemed to result in greater benefits (108968).
• Bipolar disorder. Taking magnesium orally might improve manic symptoms in some people with bipolar disorder; however, it is unclear how it compares to current standard of care. Details: One preliminary clinical study shows that magnesium 40 mEq daily (Magnesiocard) for 32 weeks has similar effects to lithium in up to 50% of patients treated for rapid cycling bipolar affective disorder (61022). Another preliminary clinical study shows that magnesium oxide 375 mg orally daily plus verapamil 80 mg taken four times daily reduces manic symptoms more effectively than verapamil alone in patients with mania (60742).
• Cancer-related neuropathic pain. It is unclear if intravenous magnesium is beneficial for this condition. Details: Single 500 mg to 1 gram doses of magnesium sulfate seem to relieve neuropathic pain for up to four hours when compared to baseline (6846). The validity of this finding is limited by the lack of a comparator group.
• Cardiac arrest. Intravenous magnesium does not seem to be helpful in cardiac arrest; however, the risk of sudden cardiac death seems to be inversely correlated to higher plasma magnesium levels or dietary intake. It is unclear if magnesium supplementation is associated with similar risk reduction. Details: Administering magnesium intravenously doesn't seem to improve successful resuscitation in people with cardiac arrest (1190). However, higher plasma magnesium levels and higher dietary magnesium intake might reduce the risk of sudden cardiac death, possibly by protecting against fatal ventricular arrhythmias. In the Nurses' Health Study, the risk of sudden cardiac death was 77% lower in females with the highest quartile of plasma magnesium levels when compared with the lowest quartile. Also, the risk was 37% lower in females with the highest quartile of dietary magnesium intake when compared with the lowest quartile (17132).
• Cardiovascular disease (CVD). Evidence regarding the effect of dietary magnesium on CVD risk is conflicting. Details: Epidemiological research in some populations shows that increased dietary magnesium intake is associated with decreased mortality due to strokes, coronary heart disease, ischemic heart disease, and heart failure, but other epidemiological research does not show any effect on these risks (89391,90003,90009,90030,90036,103735). Reasons for the discrepancies may be related to serum levels of magnesium at baseline, risk of cardiovascular disease at baseline, use of concomitant medications such as diuretics, or the presence of concomitant conditions such as kidney dysfunction. A population analysis conducted in Denmark has found that magnesium intake from drinking water may be associated with cardiovascular mortality. The overall risk of cardiovascular death and death due to stroke was reduced by 4% in the lowest 3 quintiles of intake when compared with the highest quintile. However, the risk of death due to acute myocardial infarction was increased by 22% in the lowest quintile when compared with the highest (108726). The relevance of these results is unclear, given that the main dietary source of magnesium is food rather than drinking water.
• Chronic fatigue syndrome (CFS). Limited evidence suggests that magnesium may help improve CFS symptoms, but this is controversial. Details: In people with low red blood cell magnesium, there is some evidence that intramuscular injections of 1 gram magnesium sulfate given once weekly for 6 weeks might improve CFS symptoms (7556). However, there is additional evidence that most patients with CFS have normal magnesium stores, and measurement of red cell magnesium is a poor indicator of total magnesium stores (7557,8084,8085,8086,8087).
• Chemotherapy-induced leukopenia. It is unclear if oral magnesium is beneficial in pediatric patients at risk for cisplatin-induced febrile neutropenia. Details: A small clinical study in children with solid tumors aged 9 years and older shows that taking magnesium 250 mg daily while receiving cisplatin-based chemotherapy reduces febrile neutropenia by 47% and septic shock by 57% when compared with not receiving magnesium. Results from this study suggest that four pediatric patients need to take oral magnesium to avoid one case of febrile neutropenia (104394).
• Chemotherapy-induced nephrotoxicity. It is unclear if intravenous magnesium is beneficial for chemotherapy-induced nephrotoxicity. Details: A meta-analysis of several lower quality clinical studies in adults in Japan with cancer receiving cisplatin shows that pretreatment with intravenous magnesium sulfate 5 to 20 mEq reduces the odds of chemotherapy-induced nephrotoxicity in a dose-dependent manner when compared to standard hydration therapy (115726). The validity of these findings is limited by heterogenous methods between clinical trials, including types of cancer, definitions of nephrotoxicity, and use of other nephroprotective therapies.
• Chronic obstructive pulmonary disease (COPD). Intravenous, but not nebulized, magnesium may be helpful in acute exacerbations of COPD. Details: Administering magnesium sulfate intravenously, 1.2-2.5 grams over 20 minutes, might be helpful for treating acute exacerbations of COPD (1208,6844,103733). Also, giving magnesium sulfate 2 grams intravenously seems to improve exercise capacity when compared with placebo (89384). A meta-analysis of studies using intravenous magnesium sulfate for COPD exacerbations shows that it reduces hospital admission and mean length of stay and improves dyspnea scores when compared with placebo. Based on the relative risk identified in the included studies, seven patients would need to receive intravenous magnesium to prevent one hospitalization. However, intravenous magnesium sulfate does not change the need for non-invasive ventilation and the available research did not evaluate intensive care unit (ICU) admission (108967). Nebulized magnesium has also been evaluated. In patients experiencing a COPD exacerbation, clinical research shows that administering nebulized magnesium sulfate with albuterol three times at 30-minute intervals does not improve pulmonary function as measured by the forced expiratory volume in 1 second (FEV1) when compared with placebo (89393). Also, a meta-analysis of a small number of low-quality studies shows that nebulized magnesium does not reduce hospital admission or the need for ventilatory support, although it might modestly improve dyspnea scores and reduce ICU admissions, when compared with placebo (108967).
• Cluster headache. It is unclear if a single intravenous dose of magnesium sulfate is beneficial for cluster headaches. Details: Administering magnesium sulfate intravenously, 1 gram over 5 minutes, seems to improve cluster headaches when compared with baseline(1184). The validity of this finding is limited by the lack of a comparator group.
• Cognitive impairment. It is unclear if oral magnesium is beneficial for cognitive impairment. Details: A large observational study in adults with end-stage renal disease on hemodialysis suggests that serum magnesium levels of 20.2-22.3 mg/dL are associated with the lowest odds of mild cognitive impairment, while serum magnesium levels below and above that range of values are associated with increased odds of mild cognitive impairment (111695).
• Coronary heart disease (CHD). It is unclear if magnesium supplementation is beneficial for CHD. Details: Clinical research shows that magnesium oxide 800-1200 mg daily for 3 months reduces platelet-dependent thrombosis by 35% when compared with placebo in patients with CHD (60759). It is unclear if this effect improves clinical outcomes. The effect of magnesium supplementation on coronary artery calcium has also been studied. A meta-analysis of 3 clinical studies in 196 patients with chronic kidney disease (CKD) shows that taking magnesium or increasing the concentration of magnesium in dialysate does not improve coronary artery calcification (CAC) scores when compared with standard therapy. However, magnesium reduced carotid intima-media thickness (111179). Similarly, a large clinical study in patients with CKD shows that taking slow-release magnesium hydroxide (Mablet, Denmark) 360 mg twice daily for 12 months does not slow the progression of CAC scores when compared with placebo (111178). This study may not have been adequately powered to detect a difference between groups.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral magnesium is beneficial for COVID-19. Details: A small clinical study in patients hospitalized with moderate COVID-19 shows that taking magnesium 300 mg daily for the duration of hospitalization reduces the number of patients requiring oxygen therapy but not the duration of hospital stay when compared with placebo (114680).
• Depression. It is unclear if magnesium is beneficial for the treatment or prevention of depression in adults. Details: Some population research shows that dietary intake of elemental magnesium between 76-360 mg daily is associated with a reduced risk of depression, but there was no association with greater amounts of magnesium, and other population research shows no association at any intake level (96480,98289). For treatment of mild to moderate depression, one preliminary clinical study shows that taking magnesium chloride 2 grams orally daily for 6 weeks reduces depression scores by 56% and anxiety scores by about 52% when compared to baseline (96477). The validity of these findings is limited by the lack of a comparator group. However, a small clinical study in adults with recurrent depression shows that taking magnesium aspartate 120 mg daily for 8 weeks, along with fluoxetine, does not improve depression scores when compared with patients taking fluoxetine and placebo (111185). Similarly, a very small crossover clinical study in adults with mild or moderate treatment-resistant depression shows that administering a single dose of IV magnesium sulfate 4 grams does not improve depression scores when compared with an infusion of 5% dextrose (96481). However, scores were evaluated 24 hours post-infusion which may be too soon to detect improvement. Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that elemental magnesium in doses of 100-400 mg is not recommended for adjunctive or monotherapy use in patients with depression (110318).
• Diabetic foot ulcers. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with grade 3 diabetic foot ulcers shows that taking magnesium oxide 250 mg plus vitamin E 400 IU daily for 12 weeks modestly reduces ulcer size when compared with placebo (101436). It is unclear if this effect is due to magnesium, vitamin E, or the combination.
• Exercise-induced muscle soreness. It is unclear if oral magnesium reduces muscle soreness in adults after resistance training. Details: A very small study in healthy adults, ages 19-23, shows that taking magnesium glycinate 350 mg daily for 10 days seems to reduce muscle soreness after bench press exercise when compared with placebo (104399).
• Fetal and premature infant mortality. It is unclear if antenatal intravenous (IV) magnesium sulfate administration reduces the risk of fetal and premature infant mortality. Details: Two meta-analyses of up to 7 clinical studies in patients at risk of preterm birth shows that antenatal IV magnesium sulfate administration does not reduce the risk of fetal or neonatal death when compared with placebo (114675,114681).
• Fibromyalgia. It is unclear if oral magnesium is beneficial for this condition. Details: A small clinical study shows that taking magnesium chloride orally 100 mg once daily for one month reduces mild to moderate, but not severe, stress associated with fibromyalgia when compared with placebo. It also reduces pain levels, but not to a clinically significant extent, and it does not affect sleep, fatigue, or quality of life (108964). Another small clinical study shows that taking magnesium citrate 300 mg daily for 8 weeks improves some symptoms of fibromyalgia, such as number of tender points and depression, when compared to baseline (89385). The validity of this finding is limited by the lack of a comparator group. A small clinical study shows that taking a combination of magnesium hydroxide and malic acid (Super Malic tablets) orally decreases fibromyalgia-related pain and tenderness in some patients when compared with placebo (3262). It is unclear if this effect is due to magnesium, malic acid, or the combination.
• Fractures. Population research suggests that higher intakes of magnesium may reduce fracture risk. Details: Observational research has found that higher dietary and supplemental magnesium intake is associated with a 34% lower odds of fracture when compared with lower magnesium intake (101395).
• Gastric cancer. Population research suggests that higher intakes of magnesium may reduce gastric cancer risk. Details: Observational research has found that higher dietary and supplemental magnesium intake is not associated with a reduced risk for gastric cancer when compared with lower intake (103730).
• Hearing loss. Oral magnesium may prevent and improve hearing loss due to environmental factors or loud noises. Details: Clinical research in healthy military recruits shows that taking magnesium aspartate 167 mg daily for 2 months prevents hearing loss from exposure to loud noises during basic military training when compared with placebo (1205). Also, in patients with acute-onset hearing loss that was not caused by environmental factors, taking magnesium aspartate 167 mg daily for 8 weeks seems to improve hearing loss when compared with placebo (60813).
• Hypertension. Oral magnesium supplementation may modestly reduce blood pressure, although these changes are not likely to be considered clinically significant. Details: Most research shows that taking oral magnesium supplements in daily doses that are at least as high as the Recommended Dietary Allowance (RDA) for adults and up to 1000 mg daily can lower diastolic blood pressure by about 2 mmHg in adults with or without hypertension (1192,1199,9465,15165,18111,96482). Significantly lower doses do not seem to have this effect (1180,1195,1197,8098). The effect of magnesium on systolic blood pressure is conflicting. Two meta-analyses shows that taking magnesium 212-970 mg daily does not lower systolic blood pressure in patients with or without hypertension (15165,115728). However, additional meta-analyses show that taking magnesium 120-970 mg daily can lower systolic blood pressure in a dose-dependent manner by about 2-4 mmHg in patients with or without hypertension (18111,96482). The reasons for these discrepant findings are unclear but may be due to heterogenous methods, including dose and duration among clinical studies. In 2022, the US Food and Drug Administration (FDA) approved a qualified health claim stating that inconsistent and inconclusive evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure. Products bearing this claim must provide at least 84 mg of magnesium daily, but no more than 350 mg daily (107451).
• Hypokalemia. It is unclear if intravenous or oral magnesium is beneficial for hypokalemia in patients with normal magnesium levels. Details: A preliminary retrospective observational study in patients with hypokalemia and unknown serum magnesium levels has found that administering oral or intravenous magnesium is not associated with improved time to normalization of serum potassium levels when compared with no magnesium treatment (110049). However, hypokalemia with concurrent hypomagnesemia can impede potassium repletion and exacerbate hypokalemia-induced rhythm disturbances. Standard of care in patients with hypokalemia and known hypomagnesemia includes prompt treatment with magnesium (110063).
• Impaired glucose tolerance (prediabetes). It is unclear if oral magnesium is beneficial for prediabetes. Details: Preliminary clinical research in patients with prediabetes shows that taking magnesium oxide 250 mg orally daily for 12 weeks does not improve fasting blood glucose levels, insulin resistance, or glycated hemoglobin (HbA1C) levels when compared with placebo. Taking magnesium also did not affect blood pressure, body weight, triglyceride levels, or low-density lipoprotein cholesterol levels; however, it did modestly improve high-density lipoprotein cholesterol levels (110053).
• Insomnia. Oral magnesium may modestly improve sleep complaints in adults, but evidence is conflicting. Details: A meta-analysis of two small clinical studies in healthy older adults with or without insomnia suggests that taking magnesium reduces the time to fall asleep by an average of 17 minutes when compared with placebo (105917). However, it does not increase the time spent asleep. Also, these findings are limited by imprecision and a high risk of bias. Studies included in the analysis used elemental magnesium 500-729 mg daily (as magnesium oxide) for up to 8 weeks (102458,105917). Another small clinical study in patients with poor sleep quality and low magnesium status shows that taking elemental magnesium 320 mg (as magnesium citrate) in divided doses daily for 7 weeks does not improve sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI), when compared with a sodium citrate placebo (102456). Magnesium has also been evaluated in combination with other ingredients. A very small crossover clinical study in patients aged 18-40 years without a sleep disorder shows that taking a combination of magnesium 300 mg, L-tryptophan 1000 mg, glycine 3000 mg, tart cherry 220 mg, and theanine 200 mg for 3 days reduces the time to fall asleep by about 24 minutes, increases total time asleep by about 22 minutes, and improves sleep efficiency, but does not improve the total time in bed or wakefulness after falling asleep when compared with cellulose placebo (111184). Another small crossover clinical study in adults with sleep disturbances shows that taking a combination of magnesium 200 mg and melatonin nightly for 4 weeks improves sleep quality, as measured by the PSQI, reduces the length of time it takes to fall asleep by about 17 minutes, and improves some other measures of sleep, such as sleep efficiency and number of awakenings, when compared with placebo. However, despite these improvements, overall sleep quality was still categorized as poor after the intervention (113670). It is unclear if these effects are due to magnesium, other ingredients, or the combination.
• Intraventricular hemorrhage. It is unclear if antenatal intravenous (IV) magnesium sulfate can reduce the risk for intraventricular hemorrhage in neonates. Details: A meta-analysis of clinical research in premature infants shows that if the mother received antenatal intravenous magnesium sulfate, the infant had a non-significant trend toward a reduced risk of intraventricular hemorrhage when compared with infants whose mothers received placebo (103727). This analysis may have been insufficiently powered to detect a difference between groups. Another meta-analysis of up to 6 clinical studies, some of which are included in the previously referenced meta-analysis, in patients at risk of preterm birth shows that maternal antenatal (IV) magnesium sulfate administration does not reduce the risk of intraventricular hemorrhage, but does reduce the risk of severe intraventricular hemorrhage by about 24% when compared with placebo (114681).
• Kidney stones (nephrolithiasis). Taking magnesium orally may prevent the recurrence of kidney stones, although evidence is conflicting. Details: Prophylactic treatment with magnesium hydroxide, 200 mg twice daily for one year, followed by 500 mg daily for another year, might decrease the recurrence rate of calcium stone formation (2007). However, magnesium oxide does not seem to benefit patients considered to be recurrent calcium stone formers when compared with placebo, no treatment, or chlorthalidone (8097,38501,61199). Magnesium oxide 300 mg in combination with vitamin B6 10 mg daily seems to decrease urinary oxalate levels in people with hyperoxaluria who have previously had kidney stones (1201), but it is unclear if this effect translates into a reduced incidence of kidney stones.
• Liver cancer. Increased dietary magnesium intake is linked with a lower risk of liver cancer. Details: Observational research in retired older Americans has found that higher dietary magnesium intake is associated with a 35% lower risk of liver cancer when compared with lower intake. This association was especially strong in persons who were moderate or heavy alcohol users (105080).
• Lung cancer. Supplemental or dietary magnesium intake does not seem to reduce the risk of lung cancer. Details: A large epidemiological cancer screening trial with a mean follow-up of over 12 years suggests there is no association between dietary or supplemental magnesium intake and the risk of lung cancer. However, dietary magnesium seems to play an important yet unclear role in lung cancer prevention when taken as part of the diet with alpha-carotene, vitamin C, vitamin E, lycopene, selenium, lutein, and zeaxanthin (112096).
• Migraine headache. Oral magnesium may help prevent migraine in some adults and children. Also, intravenous magnesium may help treat migraine in adults, but evidence is conflicting. Details: A meta-analysis of 4 low-quality clinical studies, in adults with migraine shows that magnesium 122-600 mg daily for 4-16 weeks modestly reduces migraine frequency and severity when compared with placebo(115730). However, clinical significance is unclear, and the validity of these findings is limited by heterogeneous methods between clinical trials, including type of magnesium formulation and dose, patient population, and duration. In contrast, one small clinical study shows that taking magnesium does not reduce migraine frequency and severity by at least 50% in adults when compared with placebo (10661). Limited evidence suggests that adding oral magnesium to conventional treatment may also be beneficial. A clinical study in adults with migraine living in Iran shows that taking magnesium oxide 250 mg twice daily in addition to sodium valproate 200 mg twice daily for 12 weeks modestly reduces severity and duration of migraine, but not migraine frequency, when compared with taking sodium valproate alone (105915). It is unclear if these improvements would be considered clinically significant. For treatment of migraine, some adults with normal magnesium levels respond to intravenous (IV) magnesium sulfate 1 gram over 5 minutes, but most patients who benefit have low magnesium levels at baseline (1185,6844). Effects of IV magnesium in patients with unknown magnesium levels are conflicting. Some preliminary clinical research shows that magnesium 1-2 grams IV alleviates acute migraine for up to 2 hours, but other research has found no benefit (89388,97493,98285). In children, treatment with magnesium oxide orally 15 mg/kg daily in 3 divided doses for up to 16 weeks reduces the frequency and severity of migraine headaches when compared with placebo (10663). However, adding magnesium sulfate 400 mg orally daily to ibuprofen or acetaminophen does not further reduce migraine severity in children (89396).
• Miscarriage. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in pregnant adults with threatened miscarriage between the 6th and 13th week of gestation shows that taking a specific combination product (DAV HA, Lo.Li pharma s.r.l) containing magnesium 450 mg, alpha-lipoic acid, hyaluronic acidvitamin B6, and vitamin D daily in combination with conventional treatment of vaginal progesterone over 2 weeks of observation results in a faster resorption of the subchorionic hematoma and faster decrease of patient-reported vaginal bleeding, abdominal pain, and uterine contractions when compared with vaginal progesterone alone (113893). It is unclear if these effects are due to magnesium, other ingredients, or the combination. Additionally, the validity of these findings is limited by the lack of a placebo in the control group.
• Myocardial infarction (MI). Research on the effects of intravenous or oral magnesium after myocardial infarction are conflicting. Details: Administering magnesium intravenously doesn't seem to reduce mortality after an acute MI (8999,13357,13358,13359,13360,19990,60872,61082), although there is some conflicting evidence from a meta-analysis of clinical research that shows that intravenous magnesium sulfate may reduce short-term mortality by 55% when compared with placebo (60795,60895). Clinical research with oral magnesium supplementation has found no benefit (1198,6844).
• Neonatal encephalopathy. Intravenous magnesium may improve short-term outcomes in neonates with encephalopathy. Details: A meta-analysis of clinical research shows that intravenous magnesium may improve short term outcomes of neonatal encephalopathy (hypoxic ischemic encephalopathy, HIE). However, long term outcomes are not affected (90025).
• Nocturnal leg cramps. It is unclear if oral magnesium is helpful for nocturnal leg cramps. Details: Some clinical research in adults with nocturnal leg cramps shows that taking magnesium oxide 865 mg daily at bedtime for 4 weeks does not reduce the frequency of leg cramping episodes when compared with placebo (96478). However, four weeks may be too short a time to see a benefit. In other clinical research, taking oral magnesium oxide monohydrate 226mg daily at bedtime for 60 days reduces the frequency of leg cramps when compared with placebo. This reduction was not seen after 30 days. Magnesium also reduced cramp duration and improved sleep quality, but did not affect pain scores, at 60 days when compared with placebo (106919).
• Nonalcoholic fatty liver disease (NAFLD). Oral magnesium hydroxide has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with NAFLD shows that taking magnesium hydroxide 150 mg and L-carnitine 2000 mg daily for 16 weeks does not improve liver stiffness scores when compared with baseline or controls who took placebo for 8 weeks followed by this magnesium and L- carnitine combination for 8 weeks. Taking magnesium and L-carnitine also did not improve levels of aspartate aminotransferase (AST) or alanine transaminase (ALT) when compared to baseline (111177).
• Obesity. Evidence on the use of magnesium for weight loss in obese patients is conflicting; any benefit is likely small at best. Details: A meta-analysis of 7 clinical studies in obese patients shows that taking magnesium reduces body mass index (BMI) by 0.3 when compared with control (103723). Another meta-analysis of 7 studies in obese patients shows that while magnesium supplementation does not reduce weight, it reduces waist circumference by 2 cm when compared with placebo (103729). Interestingly, subgroup analyses did not find that the dose of magnesium or baseline magnesium levels impacted effectiveness. One subgroup analysis found that magnesium supplementation lasting 12 weeks or less seemed to be more beneficial for obesity than supplementation lasting longer than 12 weeks (103723).
• Overall mortality. It is unclear if oral or IV magnesium reduces the risk of overall mortality. Details: A meta-analysis of heterogeneous observational studies has found that increased dietary magnesium intake, but not supplemental magnesium intake, is associated with a modestly reduced risk of overall mortality (105073). A meta-analysis of 3 small, low-quality clinical studies in ICU patients shows that administering IV magnesium 24-30 mmol or as a target-directed dose for 3 days reduces overall mortality when compared with patients who did not receive magnesium (111290). However, some studies included patients with hypomagnesemia; it is unclear if effects would be similar for patients with normal levels of magnesium.
• Osteoarthritis. Population research has not found a link between magnesium intake and osteoarthritis risk. Details: Observational research has found that dietary and supplemental magnesium intake is not associated with the risk of developing osteoarthritis (101395).
• Pain (acute). It is unclear if locally injected or intravenous magnesium is helpful for acute pain. Details: Preliminary clinical research in patients with renal colic shows that intravenous (IV) magnesium sulfate, 50 mg/kg infused over 20 minutes, is as effective as IV morphine sulfate 0.1 mg/kg for controlling acute renal pain at 20 minutes after the dose (107367). Magnesium has also been evaluated in a dental procedure. A single-center clinical study in India in adults with irreversible pulpitis requiring a root canal shows that a local injection of 0.2 mL of 10% magnesium sulfate with lidocaine and epinephrine reduces perioperative pain when compared to lidocaine with epinephrine alone (115729).
• Pain (chronic). Population research suggests that higher intakes of magnesium may modestly reduce the risk for chronic pain. Details: A cross-sectional observational study has found that increased magnesium intake is associated with a 7% to 8% reduced risk for chronic pain. The association was found to be stronger in females than in males (103732).
• Parturition. It is unclear if topical magnesium is beneficial for labor duration. Details: A single-center clinical study in Iranian adults shows that applying 10 mL of a 50% magnesium sulfate solution directly to the cervix during the active phase of labor reduces the time to vaginal delivery by approximately 1.5 hours and improves the childbirth experience, as reported by patients, when compared with placebo. However, clinical significance is unclear (115727).
• Perioperative anxiety. It is unclear if oral magnesium is beneficial for perioperative anxiety. Details: Preliminary clinical research in adults undergoing open heart surgery shows that taking magnesium oxide 250 mg orally twice daily during hospitalization moderately improves anxiety and depression scores when compared with no magnesium therapy. Magnesium therapy was held for the 2 days immediately following surgery (110054).
• Physical performance. Oral magnesium may modestly improve physical performance in otherwise healthy, elderly females. Details: Clinical research in otherwise healthy elderly females shows that taking a magnesium oxide supplement (Easymag, Sanofi-Aventis) 900 mg daily for 12 weeks modestly improves walking speed and chair stand speed in elderly females when compared with no treatment (90026).
• Polycystic ovary syndrome (PCOS). It is unclear if oral magnesium is beneficial for improving metabolic indices in patients with PCOS. Details: Two small clinical studies in patients with PCOS show that taking magnesium oxide orally, 250 mg daily for 8 weeks, does not affect insulin resistance, beta-cell function, lipid levels, or insulin sensitivity when compared with placebo (103725,105887). Other clinical research in patients with PCOS shows that taking magnesium oxide orally, 250 mg daily for 10 weeks, improves subjective measures of quality of life, fatigue, and emotional functioning, but not objective measures such as alopecia, abnormal uterine bleeding, or acne, when compared with placebo (108965). A clinical study using a combination of magnesium 250 mg with vitamin E 400 mg daily for 12 weeks shows a modest reduction in insulin resistance, insulin levels, and triglyceride levels, but not other lipid levels, when compared with placebo (100264). It is unclear if these beneficial effects are due to magnesium, vitamin E, or the combination.
• Postoperative nausea and vomiting (PONV). It is unclear if intravenous (IV) magnesium is beneficial for PONV due to mixed results from clinical research. Details: A meta-analysis of 5 clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium sulfate intraoperatively reduces PONV (114676). However, a meta-analysis of 20 clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium perioperatively does not reduce the incidence of PONV (114678). A moderate-sized clinical study conducted in China in older adults undergoing total knee arthroplasty shows that administering intravenous magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery reduces the incidence of postoperative vomiting but not postoperative nausea when compared with control (113677). The reasons for these discrepant findings are unclear but may be explained by differences in magnesium regimens, anesthesia protocols, and surgical populations studied.
• Postoperative recovery. It is unclear if intravenous (IV) magnesium is beneficial for postoperative recovery. Details: A moderate-sized clinical study conducted in China in older adults undergoing total knee arthroplasty shows that administering IV magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery does not reduce extubation time, time spent in the post-anesthesia care unit (PACU), or duration of hospital stay when compared with control (113677). Additionally, a meta-analysis of 3 different clinical studies in adults undergoing surgery with general anesthesia shows that administering IV magnesium intraoperatively does not reduce extubation time (114676).
• Postoperative sleep disturbance. It is unclear if oral magnesium is beneficial for postoperative sleep disturbances. Details: Preliminary clinical research in adults undergoing open heart surgery shows that taking magnesium oxide 250 mg orally twice daily during hospitalization moderately improves sleep scores when compared with no magnesium therapy. Magnesium therapy was held for the 2 days immediately following surgery (110054).
• Postoperative sore throat. It is unclear if topical magnesium sulfate is beneficial for reducing sore throat pain after endotracheal intubation. Details: Preliminary clinical research in patients undergoing endotracheal intubation for surgery shows that using a gargle containing magnesium sulfate 20% with lidocaine, 20 minutes before anesthesia induction, is less effective for reducing sore throat pain than a gargle containing dexmedetomidine and lidocaine (112779). The study did not include a comparison to lidocaine alone.
• Pregnancy-related leg cramps. It is unclear if oral magnesium reduces leg cramps during pregnancy; evidence is conflicting. Details: One small clinical study in patients with pregnancy-related leg cramps shows that taking magnesium bisglycinate chelate 300 mg daily for 4 weeks reduces the frequency and intensity of leg cramps when compared with placebo (99318). A smaller clinical study in this population shows that taking a specific mixture of magnesium lactate and citrate (Nycoplus Magnesium) providing elemental magnesium 120 mg in the morning and 240 mg in the evening for 3 weeks reduces the frequency of cramps when compared with placebo (1194). However, not all research agrees. One small clinical study using this same supplement and dose for 2 weeks found no benefit when compared with placebo (17463). It is possible that a 2-week duration of treatment is too short to be beneficial. Finally, a meta-analysis of these studies and one other more recent clinical study shows that taking magnesium does not reduce the frequency or improve the resolution of pregnancy-related leg cramps when compared with placebo (105916). This analysis may not have been adequately powered to detect a difference between treatment groups.
• Pre-procedural sedation. It is unclear if intravenous magnesium is beneficial when administered in addition to other medications used for sedation during surgery. Details: A moderate-sized study of adults aged 65-79 years old undergoing endoscopic retrograde cholangiopancreatography (ERCP) shows that administering a single intravenous bolus of magnesium sulfate 40 mg/kg prior to the procedure reduces intraoperative propofol requirements by about 21% and reduces some peri-procedural adverse events including the incidence of respiratory depression and involuntary movement when compared with control. However, there were no differences in recovery time, hemodynamic parameters, or the incidence of hypotension, bradycardia, perioperative nausea or vomiting, lethargy, or arrythmias (111694). Another moderate-sized study in older adults undergoing total knee arthroplasty shows that administering intravenous magnesium sulfate 40 mg/kg prior to anesthesia induction then 15 mg/kg during surgery does not reduce the need for medications used for anesthesia induction, intraoperative maintenance propofol requirements, or recovery time when compared with control. However, magnesium sulfate does seem to reduce the amount of remifentanil required for intraoperative anesthesia maintenance and increase norepinephrine requirements when compared with control (113677).
• Preterm labor. The use of magnesium sulfate to inhibit uterine contractions in preterm labor (tocolysis) is controversial. However, its use for the purpose of fetal neuroprotection for up to 48 hours is supported by the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine. Details: Magnesium is given intravenously (IV) during preterm labor in an effort to improve fetal neurological outcomes, such as to reduce the risk of cerebral palsy and motor dysfunction in the infant (60915,60927,60931,61001,97485,103734,103754,114681). The typical dosage of magnesium sulfate is 4 grams infused IV over 10-30 minutes, followed by a maintenance infusion of 1-4 grams/hour for 48 hours or until birth. Use beyond 5-7 days has been associated with hypocalcemia and bone abnormalities in the fetus (15,12590,12594). Some meta-analyses of clinical research suggest that magnesium sulfate is more effective at delaying delivery by 48 hours when compared with oxytocin receptor blockers, nitrates, beta-mimetics, and/or placebo (20263,61021). However, an additional meta-analysis of several clinical studies shows that magnesium sulfate 4 or 6 grams IV is not more effective at delaying preterm labor by 48 hours when compared with nifedipine (115639). The reason for these discrepant findings are unclear, but may be related to the heterogenous methods between clinical trials, including dose and duration.
• Pseudoxanthoma elasticum (PXE). It is unclear if oral magnesium is beneficial for PXE. Details: Preliminary clinical research in patients with PXE shows that taking magnesium oxide 800 mg (500 mg of elemental magnesium) twice daily for one year tends to reduce calcification of elastic skin fibers when compared with placebo, but the effect is not statistically significant (101393). This study was limited by small size and insufficient power to detect smaller effects.
• Restless legs syndrome (RLS). It is unclear if oral magnesium is beneficial for RLS. Details: Some observational research has found that hypomagnesemia is associated with RLS; however, not all research agrees (8096,9472). Preliminary clinical research in adults with RLS who are beginning treatment with pramipexole shows that also taking magnesium oxide 250 mg orally daily for 2 months moderately improves RLS scores and sleep quality scores when compared with pramipexole and placebo (110052). Other low-quality clinical research in adults with RLS or periodic limb movement during sleep shows that taking magnesium 12.4 mmol orally in the evening for 4-6 weeks decreases movement and increases sleep when compared with baseline (9466). The validity of this finding is limited by the lack of a comparator group.
• Sarcopenia. It is unclear if oral magnesium is beneficial for the prevention or treatment of sarcopenia. Details: Population research in older adults has found that lower dietary intake of magnesium is associated with sarcopenia. However, the effect of magnesium supplementation on sarcopenia prevention or treatment has not been evaluated (110055). Magnesium has been evaluated in combination with other ingredients for treatment of sarcopenia. A small clinical study in elderly individuals with sarcopenia undergoing a diet and exercise program shows that taking a combination supplement containing magnesium 300 mg, carnosine, hydroxymethylbutyrate, lactoferrin, and sodium butyrate daily for 4 months increases muscle mass, as measured by the skeletal muscle index, and improves measures of muscle function, including handgrip muscle strength, chair test, and walking speed, when compared with placebo (114682). It is unclear if these effects are due to magnesium, other ingredients, or the combination.
• Sepsis. It is unclear if intravenous magnesium is beneficial for sepsis. Details: A very large observational study in patients with sepsis and hypomagnesaemia or normomagnesemia in the intensive care unit (ICU) suggests that administering intravenous magnesium sulfate 2 or 4 grams within 24 hours of admission reduces 28-day all-cause mortality from 25% in patients who did not use magnesium sulfate to 20% in those who were administered magnesium sulfate, regardless of baseline serum magnesium level and other baseline characteristics. Administration of intravenous magnesium sulfate in this population may also reduce ICU mortality by 4%, in-hospital mortality by 3%, and the use of renal replacement therapy by 3% but also seems to increase the length of ICU and hospital stay when compared with patients who did not use magnesium sulfate (113676). The validity of these results is limited by the observational nature of the study.
• Sleep deprivation. Oral magnesium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in sleep-deprived recreational athletes shows that taking a combination of magnesium 1350 mg, zinc 90 mg, and vitamin B6 31.5 mg for 3 nights at bedtime does not change sleep quality, subjective sleepiness, mood, or fatigue the next day when compared with placebo (113655).
• Stroke. Increased dietary magnesium may decrease stroke risk, and using a magnesium-containing salt substitute may improve neurological performance post-stroke. However, intravenous magnesium has not demonstrated benefit. Details: Most population research has found that increased dietary intake of magnesium is associated with decreased stroke risk and decreased mortality from stroke (9001,9002,90013,90030,90036,92107,103736). In patients who have had a stroke, a preliminary clinical study shows that using a salt substitute providing the Dietary Reference Intake (DRI) of magnesium and potassium for 6 months improves neurological performance when compared with using regular salt (97491). However, intravenous (IV) magnesium does not seem to be beneficial in patients who have had a stroke. Large prospective clinical trials show that IV magnesium given within 12 hours of acute stroke does not reduce mortality or disability in most patients when compared with placebo. However, one subgroup analysis suggested that IV magnesium might benefit patients with lacunar (non-cortical) stroke (13361,90021). IV magnesium also doesn't seem to reduce cardiovascular complications after acute stroke. A secondary analysis of a clinical trial in patients after ischemic and hemorrhagic stroke shows that giving IV magnesium does not reduce serious cardiac adverse events when compared with placebo (104393). Another secondary analysis of this trial shows that giving IV magnesium prior to arrival at the hospital and within 2 hours of a hemorrhagic stroke does not reduce hematoma volume on hospital arrival, hematoma expansion during hospital admission, or functional outcomes at 3 months (108733).
• Subarachnoid hemorrhage. Intravenous magnesium sulfate may reduce the risk of adverse outcomes in people with subarachnoid hemorrhage, but evidence is conflicting. Details: There is mixed evidence regarding the effect of magnesium sulfate in managing aneurysmal subarachnoid hemorrhage. One meta-analysis of clinical research shows that intravenous magnesium sulfate 64-144 mmol/day for 10-18 days reduces the risk of poor outcomes following aneurysmal subarachnoid hemorrhage, including death, vegetative state, or dependency, by 46% when compared with control (60932). Also, meta-analyses of clinical research show that intravenous magnesium reduces the risk of delayed cerebral ischemia by 27% when compared with placebo (60944,89398). However, these results were not confirmed in other meta-analyses (60973,90034).
• Thrombocytopenia. It is unclear if intravenous magnesium sulfate is beneficial in patients with thrombotic thrombocytopenic purpura (TTP). Details: Addition of intravenous magnesium sulfate as a 6-gram loading dose followed by 6 grams infused over 24 hours for 3 days, to standard treatment for TTP does not reduce the time to normalization of the platelet count, the incidence of TTP-related organ dysfunction, or the recurrence rate, when compared with standard treatment alone (112777). This study may have been underpowered to detect a difference.
• Urinary incontinence. Although there has been interest in using oral magnesium for urinary incontinence, there is insufficient reliable information about the clinical effects of magnesium for this purpose. More evidence is needed to rate magnesium for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cancer. Oral slippery elm has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Retrospective population research has found that taking a specific product containing burdock root, Indian rhubarb, sheep sorrel, and slippery elm bark (Essiac, Resperin Canada Limited) does not improve quality of life in breast cancer patients and may have a negative effect on physical well-being (37419).
• Constipation. Although there has been interest in using oral slippery elm for constipation, there is insufficient reliable information about the clinical effects of slippery elm for this purpose.
• Cough. Although there has been interest in using lozenges containing slippery elm for cough, there is insufficient reliable information about the clinical effects of slippery elm for this purpose.
• Diarrhea. Although there has been interest in using oral slippery elm for diarrhea, there is insufficient reliable information about the clinical effects of slippery elm for this purpose.
• Inflammatory bowel disease (IBD). Although there has been interest in using oral slippery elm for IBD, including Crohn disease and ulcerative colitis, there is insufficient reliable information about the clinical effects of slippery elm for this purpose.
• Irritable bowel syndrome (IBS). Oral slippery elm has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a specific formulation containing slippery elm inner bark, lactulose, oat bran, and licorice root can improve stool frequency by 20% and reduce abdominal pain and bloating in people with constipation-predominant IBS when compared to baseline. Also, taking a different formulation containing slippery elm inner bark, bilberry fruit, cinnamon quilts, and agrimony aerial parts can reduce abdominal pain, bloating, and flatulence in people with diarrhea-predominant IBS when compared to baseline, although stool frequency is increased in these individuals as well (35462). It is unclear if these findings are due to slippery elm, other ingredients, or the combination.
• Peptic ulcers. Although there has been interest in using oral slippery elm for peptic ulcers, there is insufficient reliable information about the clinical effects of slippery elm for this purpose.
• Pharyngitis. It is unclear if lozenges containing slippery elm are beneficial in patients with sore throat. Details: Slippery elm has demulcent properties and, when added to lozenges, may soothe sore throats (272,512,1740). However, clinical research is lacking. More evidence is needed to rate slippery elm for these uses.

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LIKELY SAFE ...when used orally or intravenously and appropriately. Calcium is safe when used in appropriate doses (7555,12928,12946,95817). However, excessive doses should be avoided. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: Age 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg; 19-50 years, 2500 mg; 51+ years, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stone, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). Other analyses report conflicting results and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients not to consume more than the recommended daily intake of 1000-1200 mg per day, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (93533).

POSSIBLY UNSAFE ...when used orally in excessive doses. The National Academy of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 19-50 years, 2500 mg; 51 years and older, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). Other analyses report conflicting results and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients to not consume more than the recommended daily intake of 1000-1200 mg per day, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (93533).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Calcium is safe when used in appropriate doses (17506).

CHILDREN: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately (945,1586,3263,3264,17506). The World Health Organization (WHO) recommends prescribing oral calcium supplementation 1.5-2 grams daily during pregnancy to those with low dietary calcium intake to prevent pre-eclampsia (97347).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the same daily tolerable upper intake level (UL) for calcium according to age independent of pregnancy status: 9-18 years, 3000 mg; 19-50 years, 2500 mg (17506). Doses over these amounts might increase the risk of neonatal hypocalcemia-induced seizures possibly caused by transient neonatal hypoparathyroidism in the setting of excessive calcium supplementation during pregnancy, especially during the third trimester. Neonatal hypocalcemia is a risk factor for neonatal seizures (97345).

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LIKELY SAFE ...when used orally and appropriately for medicinal purposes, short-term. Flaxseed oil has been used safely in doses up to 2 grams daily for up to 6 months. Higher doses of up to 24 grams daily has been safely used for up to 7 weeks (845,3912,5898,14443,16789,16791,16794,16795,17523,101951,101952,101955).

POSSIBLY SAFE ...when used topically for medicinal purposes, short-term. Flaxseed oil has been used safely on the wrist for up to 4 weeks (25691). ...when used in eye drops twice daily for up to 90 days (101953).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. Some evidence suggests that flaxseed oil, providing 200 mg of alpha-linolenic acid, can be safely used in children for up to 3 months (14443).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately for medicinal purposes, short-term. Although flaxseed oil has been used with apparent safety in clinical research in doses of 1-2 grams daily for up to 6 weeks (96432,101957), some population research has found that consuming flaxseed oil during the second and third trimesters of pregnancy is associated with a four-fold increased risk of premature birth (16797).

LACTATION:
Insufficient reliable information available; avoid using.

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LIKELY SAFE ...when used orally and appropriately. Lactobacillus acidophilus has been safely used as part of multi-ingredient probiotic products in studies lasting up to nine months (1731,6087,14370,14371,90231,90296,92255,103438,12775,107581)(110950,110970,110979,110998,111785,111793). ...when used intravaginally and appropriately. L. acidophilus has been used safely in studies lasting up to 12 weeks (12108,13176,13177,90265). There is insufficient reliable information available about the safety of non-viable, heat-killed L. acidophilus formulations when used orally.

CHILDREN: LIKELY SAFE
when used orally and appropriately in children of most ages. Lactobacillus acidophilus has been safely used for up to 5 days (96887). Also, combination probiotics containing L. acidophilus have been used with apparent safety in various doses and durations. L. acidophilus has been combined with Bifidobacterium animalis (HOWARU Protect, Danisco) for up to 6 months in children 3-5 years old (16847), with Bifidobacterium bifidum for 6 weeks (90602,96890), with Bifidobacterium bifidum and Bifidobacterium animalis subsp. lactis (Complete Probiotic Platinum) for 18 months in children 4 months to 5 years of age (103436), and in a specific product (Visbiome, ExeGi Pharma) containing a total of 8 species for 3 months in children 2-12 years old (107497). There is insufficient reliable information available about the safety of L. acidophilus in preterm infants with a birth weight under 1000 grams. Cases of bacteremia have occurred rarely in preterm infants given other probiotics (102416,111610,111612,111613,111850,111852,111853). The US Food and Drug Administration (FDA) has issued a warning about cases of serious infections caused by probiotics reported in very preterm or very low birth weight infants under 1000 grams (111610). Similarly, the American Academy of Pediatrics does not support the routine administration of probiotics to these infants due to conflicting data on safety and efficacy (111608).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately. A combination of Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum has been used with apparent safety for 6 weeks, starting at 24-28 weeks' gestation (95416,98430).

LACTATION:
There is insufficient reliable information available about the safety of Lactobacillus acidophilus during lactation. However, there are currently no reasons to expect safety concerns when used appropriately.

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LIKELY SAFE ...when used orally and appropriately. Oral magnesium is safe when used in doses below the tolerable upper intake level (UL) of 350 mg daily (7555). ...when used parenterally and appropriately. Parenteral magnesium sulfate is an FDA-approved prescription product (96484).

POSSIBLY UNSAFE ...when used orally in excessive doses. Doses greater than the tolerable upper intake level (UL) of 350 mg daily frequently cause loose stools and diarrhea (7555).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Magnesium is safe when used in doses below the tolerable upper intake level (UL) of 65 mg daily for children 1 to 3 years, 110 mg daily for children 4 to 8 years, and 350 mg daily for children older than 8 years (7555,89396). ...when used parenterally and appropriately (96483).

CHILDREN: LIKELY UNSAFE
when used orally in excessive doses. Tell patients not to use doses above the tolerable upper intake level (UL). Higher doses can cause diarrhea and symptomatic hypermagnesemia including hypotension, nausea, vomiting, and bradycardia (7555,8095).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately. Magnesium is safe for those pregnant and breast-feeding when used in doses below the tolerable upper intake level (UL) of 350 mg daily (7555).

PREGNANCY AND LACTATION: POSSIBLY SAFE
when prescription magnesium sulfate is given intramuscularly and intravenously prior to delivery for up to 5 days (12592,89397,99354,99355). However, due to potential adverse effects associated with intravenous and intramuscular magnesium, use during pregnancy is limited to patients with specific conditions such as severe pre-eclampsia or eclampsia. There is some evidence that intravenous magnesium can increase fetal mortality and adversely affect neurological and skeletal development (12590,12593,60818,99354,99355). However, a more recent analysis of clinical research shows that increased risk of fetal mortality seems to occur only in the studies where antenatal magnesium is used for tocolysis and not for fetal neuroprotection or pre-eclampsia/eclampsia (102457). Furthermore, antenatal magnesium does not seem to be associated with increased risk of necrotizing enterocolitis in preterm infants (104396). There is also concern that magnesium increases the risk of maternal adverse events. A meta-analysis of clinical research shows that magnesium sulfate might increase the risk of maternal adverse events, especially in Hispanic mothers compared to other racial and ethnic groups (60971,99319).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses. Tell patients to avoid exceeding the tolerable upper intake level (UL) of 350 mg daily. Taking magnesium orally in higher doses can cause diarrhea (7555). ...when prescription magnesium sulfate is given intramuscularly and intravenously prior to delivery for longer than 5 days (12592,89397,99354,99355). Maternal exposure to magnesium for longer than 5-7 days is associated with an increase in neonatal bone abnormalities such as osteopenia and fractures. The U.S. Food and Drug Administration (FDA) recommends that magnesium injection not be given for longer than 5-7 days (12590,12593,60818,99354,99355).

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POSSIBLY SAFE ...when used orally and appropriately (4,12,272,512,1740).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using. Slippery elm bark has historically been inserted into the cervix to induce abortion. As a result, slippery elm has been reported in some sources to have abortifacient activity. However, there is no reliable information available about whether slippery elm has abortifacient activity when taken orally.

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ALUMINUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.  Details Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease (21631). However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption (93006).

BISPHOSPHONATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium reduces the absorption of bisphosphonates.  Details Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates (12937).

CALCIPOTRIENE (Dovonex) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Taking calcipotriene with calcium might increase the risk for hypercalcemia.  Details Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia (12938). Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

CALCIUM CHANNEL BLOCKERS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.  Details Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects (6124). But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers (12939,12947).

CEFTRIAXONE (Rocephin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = D Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.  Details Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction (15794,21632). So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.  Details Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin (12940). However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin (38960).

DILTIAZEM (Cardizem, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of diltiazem.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

DOLUTEGRAVIR (Tivicay) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of dolutegravir.  Details Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation (93578).

ELVITEGRAVIR (Vitekta) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of elvitegravir.  Details Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation (94166).

LEVOTHYROXINE (Synthroid, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption and effectiveness of levothyroxine.  Details Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes (5082). Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism (5081,5082,6137).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.  Details Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients (38953). Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption of quinolone antibiotics.  Details Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut (4412,10339,21638,38570).

RALTEGRAVIR (Isentress) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Calcium may reduce levels of raltegravir.  Details Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir (94164). However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure (94165).

SOTALOL (Betapace) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium seems to reduce the absorption of sotalol.  Details Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes (10018).

TETRACYCLINE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium seems to reduce the absorption of tetracycline antibiotics.  Details Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut (1843).

THIAZIDE DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.  Details Thiazides reduce calcium excretion by the kidneys (1902). Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

VERAPAMIL (Calan, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of verapamil.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

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ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, using flaxseed oil in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.  Details Small clinical studies show that consuming flaxseed oil might decrease platelet aggregation and increase bleeding time (5898,21912).

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, combining flaxseed oil with other antihypertensive drugs might have additive effects and increase the risk of hypotension.  Details Some clinical evidence suggests that long-term consumption of flaxseed oil can modestly lower systolic and diastolic blood pressure, while other clinical research shows no effect (16793,96426,101941,101954,111063,111067).

EZETIMIBE (Zetia) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Concomitant use of flaxseed oil and ezetimibe reduces the absorption of alpha-linolenic acid from flaxseed oil.  Details In one clinical study, concomitant consumption of ezetimibe 10 mg daily with flaxseed oil 2 grams providing 1 gram of alpha-linolenic acid daily blocked the absorption of alpha-linolenic acid, resulting in an overall reduction in alpha-linolenic plasma levels from baseline (96433).

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ANTIBIOTIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, taking Lactobacillus acidophilus with antibiotic drugs might decrease the effectiveness of L. acidophilus.  Details L. acidophilus preparations usually contain live and active organisms. Therefore, simultaneously taking antibiotics might kill a significant number of the organisms (1740). Tell patients to separate administration of antibiotics and L. acidophilus preparations by at least two hours.

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AMINOGLYCOSIDE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Concomitant use of aminoglycoside antibiotics and magnesium can increase the risk for neuromuscular weakness.  Details Both aminoglycosides and magnesium reduce presynaptic acetylcholine release, which can lead to neuromuscular blockade and possible paralysis. This is most likely to occur with high doses of magnesium given intravenously (13362).

ANTACIDS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Use of acid reducers may reduce the laxative effect of magnesium oxide.  Details A retrospective analysis shows that, in the presence of H2 receptor antagonists (H2RAs) or proton pump inhibitors (PPIs), a higher dose of magnesium oxide is needed for a laxative effect (90033). This may also occur with antacids. Under acidic conditions, magnesium oxide is converted to magnesium chloride and then to magnesium bicarbonate, which has an osmotic laxative effect. By reducing acidity, antacids may reduce the conversion of magnesium oxide to the active bicarbonate salt.

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, magnesium may have antiplatelet effects, but the evidence is conflicting.  Details In vitro evidence shows that magnesium sulfate inhibits platelet aggregation, even at low concentrations (20304,20305). Some preliminary clinical evidence shows that infusion of magnesium sulfate increases bleeding time by 48% and reduces platelet activity (20306). However, other clinical research shows that magnesium does not affect platelet aggregation, although inhibition of platelet-dependent thrombosis can occur (60759).

BISPHOSPHONATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Magnesium can decrease absorption of bisphosphonates.  Details Cations, including magnesium, can decrease bisphosphonate absorption. Advise patients to separate doses of magnesium and these drugs by at least 2 hours (13363).

CALCIUM CHANNEL BLOCKERS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Magnesium can have additive effects with calcium channel blockers, although evidence is conflicting.  Details Magnesium inhibits calcium entry into smooth muscle cells and may therefore have additive effects with calcium channel blockers. Severe hypotension and neuromuscular blockades may occur when nifedipine is used with intravenous magnesium (3046,20264,20265,20266), although some contradictory evidence suggests that concurrent use of magnesium with nifedipine does not increase the risk of neuromuscular weakness (60831). High doses of magnesium could theoretically have additive effects with other calcium channel blockers.

DIGOXIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Magnesium salts may reduce absorption of digoxin.  Details Clinical evidence suggests that treatment with oral magnesium hydroxide or magnesium trisilicate reduces absorption of digoxin from the intestines (198,20268,20270). This may reduce the blood levels of digoxin and decrease its therapeutic effects.

GABAPENTIN (Neurontin) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = B Gabapentin absorption can be decreased by magnesium.  Details Clinical research shows that giving magnesium oxide orally along with gabapentin decreases the maximum plasma concentration of gabapentin by 33%, time to maximum concentration by 36%, and area under the curve by 43% (90032). Advise patients to take gabapentin at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

KETAMINE (Ketalar) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Magnesium might precipitate ketamine toxicity.  Details In one case report, a 62-year-old hospice patient with terminal cancer who had been stabilized on sublingual ketamine 150 mg four times daily experienced severe ketamine toxicity lasting for 2 hours after taking a maintenance dose of ketamine following an infusion of magnesium sulfate 2 grams (105078). Since both magnesium and ketamine block the NMDA receptor, magnesium is thought to have potentiated the effects of ketamine.

LEVODOPA/CARBIDOPA (Sinemet) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Magnesium can reduce the bioavailability of levodopa/carbidopa.  Details Clinical research in healthy volunteers shows that taking magnesium oxide 1000 mg with levodopa 100 mg/carbidopa 10 mg reduces the area under the curve (AUC) of levodopa by 35% and of carbidopa by 81%. In vitro and animal research shows that magnesium produces an alkaline environment in the digestive tract, which might lead to degradation and reduced bioavailability of levodopa/carbidopa (100265).

POTASSIUM-SPARING DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Potassium-sparing diuretics decrease excretion of magnesium, possibly increasing magnesium levels.  Details Potassium-sparing diuretics also have magnesium-sparing properties, which can counteract the magnesium losses associated with loop and thiazide diuretics (9613,9614,9622). Theoretically, increased magnesium levels could result from concomitant use of potassium-sparing diuretics and magnesium supplements.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Magnesium decreases absorption of quinolones.  Details Magnesium can form insoluble complexes with quinolones and decrease their absorption (3046). Advise patients to take these drugs at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

SEVELAMER (Renagel, Renvela) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Sevelamer may increase serum magnesium levels.  Details In patients on hemodialysis, sevelamer use was associated with a 0.28 mg/dL increase in serum magnesium. The mechanism of this interaction remains unclear (96486).

SKELETAL MUSCLE RELAXANTS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = A Parenteral magnesium alters the pharmacokinetics of skeletal muscle relaxants, increasing their effects and accelerating the onset of effect.  Details Parenteral magnesium shortens the time to onset of skeletal muscle relaxants by about 1 minute and prolongs the duration of action by about 2 minutes. Magnesium potentiates the effects of skeletal muscle relaxants by decreasing calcium-mediated release of acetylcholine from presynaptic nerve terminals, reducing postsynaptic sensitivity to acetylcholine, and having a direct effect on the membrane potential of myocytes (3046,97492,107364). Magnesium also has vasodilatory actions and increases cardiac output, allowing a greater amount of muscle relaxant to reach the motor end plate (107364). A clinical study found that low-dose rocuronium (0.45 mg/kg), when given after administration of magnesium 30 mg/kg over 10 minutes, has an accelerated onset of effect, which matches the onset of effect seen with a full-dose rocuronium regimen (0.6 mg/kg) (96485). In another clinical study, onset times for rocuronium doses of 0.3, 0.6, and 1.2 mg/kg were 86, 76, and 50 seconds, respectively, when given alone, but were reduced to 66, 44, and 38 seconds, respectively, when the doses were given after a 15-minute infusion of magnesium sulfate 60 mg/kg (107364). Giving intraoperative intravenous magnesium sulfate, 50 mg/kg loading dose followed by 15 mg/kg/hour, reduces the onset time of rocuronium, enhances its clinical effects, reduces the dose of intraoperative opiates, and prolongs the spontaneous recovery time (112781,112782). It does not affect the activity of subsequently administered neostigmine (112782).

SULFONYLUREAS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Magnesium increases the systemic absorption of sulfonylureas, increasing their effects and side effects.  Details Clinical research shows that administration of magnesium hydroxide with glyburide increases glyburide absorption, increases maximal insulin response by 35-fold, and increases the risk of hypoglycemia, when compared with glyburide alone (20307). A similar interaction occurs between magnesium hydroxide and glipizide (20308). The mechanism of this effect appears to be related to the elevation of gastrointestinal pH by magnesium-based antacids, increasing solubility and enhancing absorption of sulfonylureas (22364).

TETRACYCLINE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Magnesium decreases absorption of tetracyclines.  Details Magnesium can form insoluble complexes with tetracyclines in the gut and decrease their absorption and antibacterial activity (12586). Advise patients to take these drugs 1 hour before or 2 hours after magnesium supplements.

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ORAL DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.  Details Slippery elm inner bark contains mucilage, which may interfere with the absorption of orally administered drugs (19).

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General ...Orally and intravenously, calcium is well-tolerated when used appropriately.
Most Common Adverse Effects:
Orally: Belching, constipation, diarrhea, flatulence, and stomach upset.
Serious Adverse Effects (Rare):
Orally: Case reports have raised concerns about calciphylaxis and kidney stones.

Cardiovascular ...There has been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these results, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Many of these trials also only included postmenopausal females. Other analyses report conflicting results, and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Reasons for these discrepancies are not entirely clear. It may relate to whether calcium is taken as monotherapy or in combination with vitamin D. When taken with vitamin D, which is commonly recommended, calcium supplementation does not appear to be associated with an increased risk of CVD, CHD, or MI (93533,107231). Also, the association between calcium supplementation and CVD, CHD, or MI risk may be influenced by the amount of calcium consumed as part of the diet. Supplementation with calcium may be associated with an increased risk of MI in people with dietary calcium intake above 805 mg daily, but not in those with dietary calcium intake below 805 mg daily (17482). To minimize the possible risk of CVD, CHD, or MI, advise patients not to consume more than the recommended daily intake of 1000-1200 mg and to consider total calcium intake from both dietary and supplemental sources (17484). While dietary intake of calcium is preferred over supplemental intake, advise patients who require calcium supplements to take calcium along with vitamin D, as this combination does not appear to be associated with an increased risk of MI (93533).
Rarely, calcium intake can increase the risk of calciphylaxis, which usually occurs in patients with kidney failure. Calciphylaxis is the deposition of calcium phosphate in arterioles, which causes skin ulcers and skin necrosis. In a case report, a 64-year-old female with a history of neck fracture, sepsis, and ischemic colitis presented with painful leg ulcers due to calciphylaxis. She discontinued calcium and vitamin D supplementation and was treated with sodium thiosulfate and supportive care (95816).

Gastrointestinal ...Orally, calcium can cause belching, flatulence, nausea, gastrointestinal discomfort, and diarrhea (1824,1843,12950,38803). Although constipation is frequently cited as an adverse effect of calcium, there is no scientific substantiation of this side effect (1824,1843,1844,1845,12950,38978). Calcium carbonate has been reported to cause acid rebound, but this is controversial (12935,12936).

Oncologic ...There is some concern that very high doses of calcium might increase the risk of prostate cancer. Some epidemiological evidence suggests that consuming over 2000 mg/day of dietary calcium might increase the risk for prostate cancer (4825,12949). Additional research suggests that calcium intake over 1500 mg/day might increase the risk of advanced prostate cancer and prostate cancer mortality (14132). Consumption of dairy products has also been weakly linked to a small increase in prostate cancer risk (98894). However, contradictory research suggests no association between dietary intake of calcium and overall prostate cancer risk (14131,14132,104630). More evidence is needed to determine the effect of calcium, if any, on prostate cancer risk.

Renal ...Kidney stones have been reported in individuals taking calcium carbonate 1500 mg daily in combination with vitamin D 2000 IU daily for 4 years (93943).

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General ...Orally, flaxseed oil is generally well tolerated. Topically, flaxseed oil seems to be well-tolerated.
Most Common Adverse Effects:
Topically: Itching, redness.
Serious Adverse Effects (Rare):
Orally: Severe allergic reactions such as anaphylaxis.

Endocrine ...Orally, flaxseed oil might cause gynecomastia. In a case report, a 70-year-old male developed gynecomastia after taking flaxseed oil daily for 3 months. Discontinuing flaxseed oil lead to resolution of gynecomastia (105478).

Gastrointestinal ...Orally, flaxseed oil may cause a change in bowel habits, dry mouth, and dyspepsia when taken at a dose of about 5 grams daily. However, these effects have been reported by only a small number of patients (approximately 3%) (16794). High doses of flaxseed oil (30 grams per day and higher) have been associated with loose stools and diarrhea (5898,11025).

Immunologic ...Severe allergic reactions such as anaphylaxis have been reported with flaxseed oil ingestion and also in workers processing flaxseed products (6809).

Ocular/Otic ...Topically, eye drops containing flaxseed oil may cause redness and itching (101953).

Oncologic ...Flaxseed oil has not been linked to increased prostate cancer risk. Although epidemiologic research has found that high dietary intake of alpha-linolenic acid (ALA) is associated with increased prostate cancer risk (1337,2558,7147,7823,12978), this risk does not seem to apply to ALA from plant sources, like flaxseed (12909).

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General ...Orally and intravaginally, Lactobacillus acidophilus is generally well tolerated.
Most Common Adverse Effects:
Orally: Mild gastrointestinal adverse effects.
Intravaginally: Vaginal discharge.
Serious Adverse Effects (Rare):
Orally: There is concern that L. acidophilus may cause infections in some people.

Dermatologic ...Orally, in one clinical trial, a combination of Lactobacillus acidophilus La-5, Lacticaseibacillus paracasei subsp. paracasei F19, and Bifidobacterium animalis subsp. lacltis BB-12 was associated with two cases of rash, one with itching. However, it is not clear if these adverse effects were due to L. acidophilus, other ingredients, the combination, or if the events were idiosyncratic (90236).

Gastrointestinal ...Orally, taking Lactobacillus acidophilus in combination with other probiotics may cause gastrointestinal side effects including epigastric discomfort (90239), abdominal pain (90239,90291,111785), dyspepsia (90239), flatulence (107497,107520), bloating (107497,111785), diarrhea (111785), vomiting (107537), and burping (90239); however, these events are uncommon.

Genitourinary ...Intravaginally, cream containing Lactobacillus acidophilus has been shown to cause increased vaginal discharge in about 5% of patients, compared to about 1% of patients receiving placebo cream (90237). Vaginal burning was reported by one person using intravaginal L. acidophilus and Limosilactobacillus fermentum in a clinical trial (111781).

Immunologic ...Since Lactobacillus acidophilus preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients. L. acidophilus has been isolated in some cases of bacteremia, sepsis, splenic abscess, liver abscess, endocarditis, necrotizing fasciitis, pancreatic necrosis, and meningoencephalitis. Most of these cases are thought to be due to the translocation of bacteria from other locations in the body in which they occur naturally, such as the oral cavity and gastrointestinal tract (107543,111782,111792). L. acidophilus endophthalmitis has been reported rarely (111787,111795). In one case, it was related to intravitreal injections for age-related macular degeneration in a 90-year-old female with an intraocular lens (111787). In another, it occurred following cataract surgery (111795).

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General ...Magnesium is generally well tolerated. Some clinical research shows no differences in adverse effects between placebo and magnesium groups.
Most Common Adverse Effects:
Orally: Diarrhea, gastrointestinal irritation, nausea, and vomiting.
Intravenously: Bradycardia, dizziness, flushing sensation, hypotension, and localized pain and irritation. In pregnancy, may cause blurry vision, dizziness, lethargy, nausea, nystagmus, and perception of warmth.
Serious Adverse Effects (Rare):
All ROAs: With toxic doses, loss of reflexes and respiratory depression can occur. High doses in pregnancy can increase risk of neonatal mortality and neurological defects.

Cardiovascular ...Intravenously, magnesium can cause bradycardia, tachycardia, and hypotension (13356,60795,60838,60872,60960,60973,60982,61001,61031,114681). Inhaled magnesium administered by nebulizer may also cause hypotension (113466). Magnesium sulfate may cause rapid heartbeat when administered antenatally (60915,114681).
In one case report, a 99-year-old male who took oral magnesium oxide 3000 mg daily for chronic constipation was hospitalized with hypermagnesemia, hypotension, bradycardia, heart failure, cardiomegaly, second-degree sinoatrial block, and complete bundle branch block. The patient recovered after discontinuing the magnesium oxide (108966).

Dermatologic ...Intravenously, magnesium may cause flushing, sweating, and problems at the injection site (including burning pain) (60960,60982,111696,114681). In a case study, two patients who received intravenous magnesium sulfate for suppression of preterm labor developed a rapid and sudden onset of an urticarial eruption (a skin eruption of itching welts). The eruption cleared when magnesium sulfate was discontinued (61045). Orally, magnesium oxide may cause allergic skin rash, but this is rare. In one case report, a patient developed a rash after taking 600 mg magnesium oxide (Maglax) (98291).

Gastrointestinal ...Orally, magnesium can cause gastrointestinal irritation, nausea, vomiting, and diarrhea (1194,4891,10661,10663,18111,60951,61016,98290). In rare cases, taking magnesium orally might cause a bezoar, an indigestible mass of material which gets lodged in the gastrointestinal tract. In a case report, a 75-year-old female with advanced rectal cancer taking magnesium 1500 mg daily presented with nausea and anorexia from magnesium oxide bezoars in her stomach (99314). Magnesium can cause nausea, vomiting, or dry mouth when administered intravenously or by nebulization (60818,60960,60982,104400,113466,114681). Antenatal magnesium sulfate may also cause nausea and vomiting (60915,114681). Two case reports suggest that giving magnesium 50 grams orally for bowel preparation for colonoscopy in patients with colorectal cancer may lead to intestinal perforation and possibly death (90006).
Delayed meconium passage and obstruction have been reported rarely in neonates after intravenous magnesium sulfate was given to the mother during pregnancy (60818). In a retrospective study of 200 neonates born prematurely before 32 weeks of gestation, administration of prenatal IV magnesium sulfate, as a 4-gram loading dose and then 1-2 grams hourly, was not associated with the rate of meconium bowel obstruction when compared with neonates whose mothers had not received magnesium sulfate (108728).

Genitourinary ...Intravenously, magnesium sulfate may cause renal toxicity or acute urinary retention, although these events are rare (60818,61012). A case of slowed cervical dilation at delivery has been reported for a patient administered intravenous magnesium sulfate for eclampsia (12592). Intravenous magnesium might also cause solute diuresis. In a case report, a pregnant patient experienced polyuria and diuresis after having received intravenous magnesium sulfate in Ringer's lactate solution for preterm uterine contractions (98284).

Hematologic ...Intravenously, magnesium may cause increased blood loss at delivery when administered for eclampsia or pre-eclampsia (12592). However, research on the effect of intravenous magnesium on postpartum hemorrhage is mixed. Some research shows that it does not affect risk of postpartum hemorrhage (60982), while other research shows that intrapartum magnesium administration is associated with increased odds of postpartum hemorrhage, increased odds of uterine atony (a condition that increases the risk for postpartum hemorrhage) and increased need for red blood cell transfusions (97489).

Musculoskeletal ...Intravenously, magnesium may cause decreased skeletal muscle tone, muscle weakness, or hypocalcemic tetany (60818,60960,60973).
Although magnesium is important for normal bone structure and maintenance (272), there is concern that very high doses of magnesium may be detrimental. In a case series of 9 patients receiving long-term tocolysis for 11-97 days, resulting in cumulative magnesium sulfate doses of 168-3756 grams, a lower bone mass was noted in 4 cases receiving doses above 1000 grams. There was one case of pregnancy- and lactation-associated osteoporosis and one fracture (108731). The validity and clinical significance of this data is unclear.

Neurologic/CNS ...Intravenously, magnesium may cause slurred speech, dizziness, drowsiness, confusion, or headaches (60818,60960,114681). With toxic doses, loss of reflexes, neurological defects, drowsiness, confusion, and coma can occur (8095,12589,12590).
A case report describes cerebral cortical and subcortical edema consistent with posterior reversible encephalopathy syndrome (PRES), eclampsia, somnolence, seizures, absent deep tendon reflexes, hard to control hypertension, acute renal failure and hypermagnesemia (serum level 11.5 mg/dL), after treatment with intravenous magnesium sulfate for preeclampsia in a 24-year-old primigravida at 39 weeks gestation with a previously uncomplicated pregnancy. The symptoms resolved after 4 days of symptomatic treatment in an intensive care unit, and emergency cesarian delivery of a healthy infant (112785).

Ocular/Otic ...Intravenously, magnesium may cause blurred vision (114681). Additionally, cases of visual impairment or nystagmus have been reported following magnesium supplementation, but these events are rare (18111,60818).

Psychiatric ...A case of delirium due to hypermagnesemia has been reported for a patient receiving intravenous magnesium sulfate for pre-eclampsia (60780).

Pulmonary/Respiratory ...Intravenously, magnesium may cause respiratory depression and tachypnea when used in toxic doses (12589,61028,61180).

Other ...Hypothermia from magnesium used as a tocolytic has been reported (60818).

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General ...Orally, slippery elm seems to be well tolerated. A thorough evaluation of safety outcomes with topical use of slippery elm has not been conducted.

Dermatologic ...Topically, slippery elm extracts can cause contact dermatitis. The pollen is an allergen (6). Contact dermatitis and urticaria have been reported after exposure to slippery elm or an oleoresin contained in the slippery elm bark (75131).

(Read more about SLIPPERY ELM)