Premium Milk Thistle 160 mg by Natural Factors

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. However, it is unclear if this reduction is clinically significant. Details: Many clinical trials and observational studies show that intake of calcium supplements or dietary calcium modestly reduces 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 salt-sensitive people and patients with low baseline dietary calcium intake (945,972,974,976,984,1818,1819,1820,1821,6852)(13138,14406,38803,39063,39094,39221). Also, a meta-analysis of clinical research shows that calcium intake during pregnancy reduces systolic blood pressure in offspring by 1-2 mmHg (38852). 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 supplement 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).
• 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 in high risk pregnancies, especially if calcium intakes are low. Details: Although there is some conflicting evidence (971,38756), most clinical research shows that taking calcium orally 1-2 grams daily reduces pregnancy-related hypertension and pre-eclampsia (973,1833,8828,39043,39319,39426,96480). Calcium appears to reduce the risk of pre-eclampsia by about 50% when compared with placebo. One meta-analysis of 19 controlled trials involving over 29,000 pregnancies found that for every 19 females treated with calcium, one episode of pre-eclampsia would be avoided (96480). Calcium appears to have the greatest effect in individuals at high-risk of pre-eclampsia or with low calcium levels, and when taken at greater than or equal to 20 weeks of gestation (15029,38497,96480,99714). 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. 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 supplementation 1.5-2 grams daily during pregnancies at high risk of pre-eclampsia if dietary calcium intakes are low, in order to prevent pre-eclampsia (97347).
• 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 does not seem to be beneficial for breast cancer prevention. Details: Although some population research disagrees (15631,39041,95811,107237), most research shows that increased calcium intake is not associated with a reduced risk of breast cancer (15631,16715,98895,107236,107237). Subgroup analyses of population research suggest that calcium intake may reduce the risk of breast cancer in postmenopausal, but not pre-menopausal, adults (15631,107237). Another subgroup analysis in a large meta-analysis of population research also suggests that dietary intake may reduce estrogen receptor(ER)-negative breast cancer, but not ER-positive breast cancer (107236). However, most other 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: The most recent and robust meta-analysis of clinical research shows that calcium supplementation with or without vitamin D is NOT associated with reduced fractures in older adults without osteoporosis (95822). A large-scale study in postmenopausal females aged 50-79 years suggests 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 Women's Health Initiative study found that, in older females with the lowest genetic susceptibility to low bone mineral density (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. 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), most clinical research has found that increased calcium intake does not increase weight loss (12052,13138,15396,15399,38985,39004,97356). The most recent 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).

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).
• 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 oral calcium is beneficial for type 2 diabetes prevention. Details: Some population research has found that a higher intake of calcium from 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). However, population research is often limited by confounding variables. For example, one analysis found that any beneficial effect might be influenced by concomitant magnesium intake (96473). 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. This study is limited because it was not determined whether increased serum calcium was due to increased calcium intake or another factor such as parathyroid function (95815).
• 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).
• 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).
• Hypercholesterolemia. It is unclear if oral calcium is beneficial for hypercholesterolemia. Details: Some evidence shows that taking calcium carbonate 400 mg three times daily reduces low-density lipoprotein (LDL) cholesterol levels by 4% and increases high-density lipoprotein (HDL) cholesterol levels by 4% after 6 weeks of treatment when used in combination with a low-fat diet (American Heart Association Step 1) (2557). In contrast, a study in females with dyslipidemia shows that taking calcium 800 mg daily for 2 years might INCREASE total cholesterol levels by about 12 mg/dL when compared with placebo. This same study showed an association between calcium supplementation and an increase in total cholesterol levels and carotid intimal thickness in postmenopausal females, but not premenopausal females (97350). A recent meta-analysis of randomized controlled trials which included both healthy patients and patients with 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 more effective in patients with dyslipidemia at baseline. It is unclear if this effect is due to calcium, vitamin D, or the combination (107227). However, other research shows that taking a specific supplement containing calcium 600 mg plus vitamin D 200 IU (Caltrate 600 D, Wyeth Consumer Healthcare Inc.) twice daily in combination with calorie restriction does not reduce total or LDL cholesterol levels when compared with placebo (15601).
• 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).
• 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.

(Read more about CALCIUM)

POSSIBLY EFFECTIVE

• Diabetes. Oral milk thistle extracts of silymarin seem to improve glycemic control in diabetic patients. Details: A meta-analysis of 7 small heterogeneous clinical trials in patients with type 2 diabetes shows that taking milk thistle containing silymarin 210-600 mg alone or with other ingredients daily for up to 6 months reduces fasting blood glucose and glycated hemoglobin when compared with control. Sub-group analyses suggest that studies conducted for less than 3 months seem to have a greater glycemic benefit than those lasting 3 months or longer. Furthermore, there was a greater glycemic benefit when milk thistle was used in combination with other natural ingredients (105054). Most studies in the analysis used silymarin in divided doses of 420-600 mg daily, while only one study used 200 mg daily (15102,63190,97626,105054). Most of these studies were conducted in the Middle East, so it is unclear whether these results are generalizable to other geographic locations. Most studies of combination products have been conducted in Italy and involve a specific product (Berberol, PharmExtracta) containing milk thistle standardized to silymarin 105-210 mg with tree turmeric standardized to berberine 500-1000 mg (96141,105054). In addition to improving glycemic indices in patients with type 2 diabetes (105054), this product has shown glycemic benefit in patients with concomitant obesity and metabolic syndrome (97624) and in patients with type 1 diabetes (96142).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. It is unclear if oral or topical milk thistle is beneficial in patients with acne when used alone or in combination with other treatments. Details: A small clinical trial in patients with acne vulgaris shows that taking a milk thistle extract standardized to silymarin 140 mg daily for 2 months does not improve acne severity based on the Global Acne Grading system scale when compared with doxycycline 100 mg daily, and silymarin is less effective than doxycycline when evaluated using the Acne Severity Index (ASI) scale. In addition, using silymarin in combination with doxycycline does not appear to be more effective than doxycycline alone (101160). There is also interest in using milk thistle topically for acne. A clinical study in adults with acne vulgaris shows that applying a specific topical product (Silymarin CF, Skinceuticals) containing silymarin 0.5%, vitamin C 15%, salicylic acid 0.5% and ferulic acid 0.5%, twice daily for 3 months moderately improves acne scores when compared to baseline (110488). Additionally, a small quasi-experimental study in adults with mild to moderate acne suggests that applying silymarin 1.4% cream twice daily for 3 months improves global acne scores and appearance of acne when compared to baseline, but not when compared with biweekly salicylic acid chemical peels (113143). However, the interpretation of these results is limited by the use of subjective outcomes. Similarly, observational research in patients aged 12-25 years with mild-to-moderate acne has found that applying a specific cream (Cleanance Comedomed, Pierre Fabre Dermo-Cosmetique) containing milk thistle fruit extract 25% twice daily for 8-12 weeks as initial or add-on therapy moderately improves acne scores when compared to baseline (111175). The interpretation of these results is limited by the lack of a comparator group. Further, most patients were also prescribed other skincare products or treatments.
• Alcohol-related liver disease. It is unclear if oral milk thistle is beneficial in patients with alcohol-related liver disease, as evidence is conflicting. Details: Some preliminary research shows that taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 420 mg orally daily for one month to 4 years improves some liver function tests (2613,2618,17228,63260,63339). Some studies also report improvements in liver histology and survival (2616,17228,63278). However, in other studies, taking a similar dose of the same product for 3 months to 2 years is not associated with any benefit over placebo (7321,7322,7355,63158). A meta-analysis of clinical research also shows that milk thistle extract does not reduce mortality or complications related to liver disease in patients with alcohol-related liver disease (63192). Reasons for the conflicting findings are unclear but might relate to the low methodological quality of many of these studies.
• Allergic rhinitis (hay fever). It is unclear if oral milk thistle is beneficial in patients with allergic rhinitis. Details: One preliminary clinical trial shows that taking a milk thistle extract of silymarin 140 mg orally three times a day plus cetirizine (Zyrtec) 10 mg daily for one month decreases the severity of allergic rhinitis symptoms when compared with placebo plus cetirizine (18105).
• Alzheimer disease. Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a supplement containing a milk thistle extract of silymarin 150 mg in combination with ferulic acid, gamma-oryzanol, and apigenin orally twice daily for 3 months to 2 years may stabilize mental functioning in patients with Alzheimer disease when compared to baseline (63223). It is unclear if this effect is due to milk thistle, other ingredients, or the combination.
• Amanita mushroom poisoning. While an intravenous milk thistle constituent, silibinin, has been studied for treating Amanita mushroom poisoning, this product is not readily available in the U.S. Details: Preliminary evidence from uncontrolled studies shows that administering silibinin, a constituent of milk thistle, intravenously (IV) within 48 hours of Amanita phalloides (death cap) mushroom poisoning, followed by oral therapy, may lessen liver damage (2615,63293). However, silibinin is not readily available in the US.
• Benign prostatic hyperplasia (BPH). Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a milk thistle extract of silymarin 190 mg along with selenium 80 mcg orally three times daily for 6 months may improve lower urinary tract symptoms, urinary flow rates, and residual volumes in adults aged 45-70 years with BPH when compared with placebo (88155). It is unclear if these effects are due to milk thistle, selenium, or the combination.
• Beta-thalassemia. Meta-analyses of clinical studies in patients with beta-thalassemia suggest that oral silymarin, a constituent of milk thistle, reduces serum ferritin levels. Details: Most small clinical studies and meta-analyses of these studies show that taking silymarin in conjunction with conventional iron chelation medications such as deferiprone, deferasirox, or deferoxamine, is more effective for reducing serum ferritin levels than taking a conventional medication alone (88154,98452,107375). In one meta-analysis, the combination of silymarin and deferasirox appeared to be more effective than combinations with other iron chelation medications (107375). However, one preliminary clinical study in patients 12 years of age and older with beta-thalassemia shows that taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 140 mg orally three times daily for 3 months, in conjunction with deferoxamine, does not improve serum ferritin when compared with deferoxamine alone (63212). This difference in outcome is likely due to the shorter duration of therapy. Silymarin also does not seem to affect total iron binding capacity or liver iron concentration in patients with beta-thalassemia (107375).
• Chemotherapy-induced acral erythema. It is unclear if topical milk thistle is beneficial in patients with acral erythema due to capecitabine. Details: Preliminary clinical research shows that applying a gel containing a milk thistle extract of silymarin 1% twice daily to the hands and feet, starting from the first day of chemotherapy and continuing for 9 weeks thereafter, prolongs the time to onset of acral erythema and decreases its severity when compared with placebo in patients with gastrointestinal cancer who are receiving capecitabine for the first time (95022).
• Chemotherapy-induced hepatotoxicity. Results of clinical studies are mixed over whether oral milk thistle prevents or improves chemotherapy-induced hepatotoxicity. Details: One small clinical study in children and adults up to age 21 with acute lymphoblastic leukemia (ALL) and elevated liver function tests (LFTs) shows that taking a specific product containing the milk thistle constituent silibinin (Siliphos, Thorne Research, Inc.) 80-320 mg (depending on patient weight) daily for 28 days concurrently with chemotherapy does not improve LFTs or bilirubin levels when compared with placebo (63218). Another small clinical study in patients with non-metastatic breast cancer receiving doxorubicin, cyclophosphamide, and paclitaxel shows that taking a specific milk thistle extract of silymarin (Livergol, Goldaru Pharmaceutical Company) 140 mg three times daily with meals for 4 weeks does not improve fatty liver grading or LFTs when compared with placebo (105795). Conversely, a large clinical study in children aged 5-14 with elevated liver enzymes and receiving chemotherapy for ALL shows that taking silymarin 70 mg capsules twice daily or 50 mg syrup three times daily for 9 months modestly improves aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin levels, but does not improve alkaline phosphatase or albumin levels (113144). Similarly, observational research in patients with a variety of solid tumors and elevated LFTs due to chemotherapy or targeted therapy suggests that taking silymarin 150-900 mg daily is associated with reduced or stabilized LFTs in over half of patients; however, doses above 300-450 mg daily don't seem to have much more benefit (111176). The interpretation of these results is limited by the lack of a comparator group.
• Chemotherapy-induced nephrotoxicity. It is unclear if oral milk thistle is beneficial for the prevention of cisplatin-induced nephrotoxicity. Details: A small clinical study shows that taking a milk thistle extract standardized to 70% to 80% silymarin (Liverherb, Amin Pharmaceutical Company) 140 mg orally three times daily with meals, starting 24-48 hours before cisplatin and continuing until the end of three 21-day cycles, does not prevent cisplatin-induced nephrotoxicity when compared with placebo (95025).
• Cirrhosis. It is unclear if oral milk thistle extracts of silymarin are beneficial for cirrhosis from various causes. Details: Preliminary clinical research shows that taking a milk thistle extract of silymarin 420 mg orally daily for up to 4 years might improve liver function tests and decrease mortality in people with cirrhosis due to a variety of causes (2616,63145,63278,63340). However, a meta-analysis of clinical research evaluating milk thistle studies for the treatment of various liver diseases shows that effect sizes are generally small or lack statistical significance (63161).
• Contrast induced nephropathy. It is unclear if oral milk thistle is beneficial for reducing the risk of nephropathy from contrast agents. Details: Population research in Taiwanese patients with liver cirrhosis has found that taking silymarin daily for at least 90 days during a one-year period does not reduce the risk of contrast-induced nephropathy during the following four or more years (98453).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral milk thistle is beneficial for COVID-19. Details: Preliminary clinical research in adults hospitalized with COVID-19 requiring non-invasive oxygen support shows that taking a specific milk thistle product (SinaLive, Exir Nano Sina Company), 70 mg orally three times daily for 2 weeks, does not improve time to symptom resolution, lung scores, or length of stay when compared with placebo (109504).
• Critical illness (trauma). It is unclear if oral milk thistle is beneficial in critically ill patients with trauma-induced liver injury. Details: One small clinical study in patients admitted to the intensive care unit (ICU) due to trauma-induced liver injury shows that taking a specific milk thistle extract (Livergol, Goldaru Pharmaceutical Company) containing silymarin 140 mg three times daily for 14 days reduces markers of liver injury, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), when compared with placebo (105793). Whether this milk thistle extract improves morbidity, mortality, or length of ICU stay in these patients is unclear.
• Diabetic nephropathy. It is unclear if oral milk thistle is beneficial for improving kidney function in patients with this condition. Details: Preliminary clinical research in type 2 diabetic patients with diabetic nephropathy shows that taking a milk thistle extract of silymarin 140 mg orally three times daily for 3 months, in combination with conventional treatment decreases the urine albumin to creatinine ratio when compared with placebo. However, serum creatinine and estimated glomerular filtration rate are not improved (63250).
• Dyspepsia. Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A specific combination product containing milk thistle (Iberogast, Medical Futures, Inc.) seems to improve symptoms of dyspepsia. The combination includes milk thistle plus peppermint leaf, German chamomile, caraway, licorice, clown's mustard plant, celandine, angelica, and lemon balm (19532). A meta-analysis of clinical research using this combination product shows that taking 1 mL orally three times daily over a period of 4 weeks reduces severity of acid reflux, epigastric pain, cramping, nausea, and vomiting when compared with placebo (13089).
• Endometriosis. It is unclear if oral milk thistle is beneficial in patients with endometriosis. Details: Preliminary clinical research in females with ovarian endometrioma shows that taking a specific silymarin product (Goldaru Pharma) 140 mg twice daily for 12 weeks moderately improves pain scores, but not other sexual function scores, when compared with placebo (110486). However, some researchers have also recommended to avoid using milk thistle in estrogen-sensitive conditions, such as endometriosis, due to its estrogenic effects (93025,93026).
• Hepatitis. Small clinical studies suggest that oral milk thistle extracts of silymarin may improve hepatitis symptoms. It is unclear whether these products can improve liver function in these patients. Details: In people with hepatitis due to a variety of causes, taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 140 mg orally three times daily for 4 weeks reduces symptoms such as jaundice, dark urine, and scleral icterus, but does not improve liver function tests (LFTs) (63210,63317). However, some improvements in LFTs are seen with a silybin-phosphatidylcholine complex (Silipide, Inverni della Beffa Research and Development Laboratories) taken as 160-360 mg orally daily for 2 weeks to 3 months (63320,63321). However, there are methodological problems with these latter studies.
• Hepatitis B. Small clinical studies suggest that oral milk thistle extracts may improve liver function in people with hepatitis B, although it is unclear if these products can improve disease-related complications. Details: Preliminary clinical studies suggest that taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 140 mg orally three times daily for 28 days to one year, or a silybin-phosphatidylcholine complex (Silipide, Inverni della Beffa Research and Development Laboratories) 240 mg orally twice daily for 7 days, improves liver function tests (LFTs) and liver histology (7356,63263,63299). However, another study shows that taking a milk thistle extract of silymarin 140 mg orally three times daily for 5-25 days has no effect of LFTs (63288). A meta-analysis of clinical research and a review conclude that any clinical effect of milk thistle in people with viral hepatitis is very limited and results suggest that it lacks a significant effect on mortality, liver disease complications, or liver histology (17228,63192).
• Hepatitis C. Small clinical studies suggest that oral milk thistle extracts may improve liver function but do not seem to reduce hepatitis C virus (HCV) RNA levels. Details: Preliminary clinical studies show that taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 140 mg orally three times daily for 3-12 months, or a silybin-phosphatidylcholine complex (Silipide, Inverni della Beffa Research and Development Laboratories) 240 mg orally twice daily for 7 days, improves liver function tests (LFTs) and liver histology (7356,63299). However, other studies report that taking silymarin 125-140 mg three times daily for up to one year, 166 mg twice daily for 3 months, or 400 mg daily for 8 weeks does not improve serum HCV RNA levels, anti-HCV antibody levels, LFTs, or hepatomegaly (13170,63208,63247,63288,108658). Also, taking higher doses of silymarin, up to 700 mg three times daily for 6 months, does not have a significant effect on serum HCV RNA levels or LFTs when compared with placebo (63251). A meta-analysis of clinical research and a review conclude that any clinical effect of milk thistle in people with viral hepatitis is limited and most results show that milk thistle lacks a significant effect on mortality, liver disease complications, or liver histology (17228,63192,88156). Preliminary clinical research in adults with HCV-related advanced chronic liver disease shows that taking a specific milk thistle combination product containing silybinphospholipid complex 303 mg, vitamin D 10 mcg, and vitamin E 15 mg (Realsil 100 D, Ibi Lorenzini), twice daily for 12 months, improves liver stiffness scores, but not liver fibrosis scores, when compared with control (108659). It is unclear if this effect is due to milk thistle, other ingredients, or the combination.
• Hypercholesterolemia. Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of three clinical trials in adults with hypercholesterolemia shows that taking a specific combination product (Berberol, PharmExtracta) containing milk thistle extract 105 mg and tree turmeric extract 588 mg twice daily for 3 months, along with diet and exercise, reduces levels of low-density lipoprotein (LDL) cholesterol by an average of 34 mg/dL when compared with diet and exercise alone. There was no effect on high-density lipoprotein (HDL) cholesterol or triglyceride levels (101158). The studies included in this meta-analysis are generally of low quality, lasted for no more than 12 months, and sometimes include patients with statin intolerance (95019,96140,101158). It is unclear if the effects of this product are due to milk thistle extract, tree turmeric extract, or the combination. Other clinical research shows that taking a similar product (Berberol K, PharmExtracta) containing milk thistle extract 105 mg, tree turmeric extract of berberine 500 mg, and monacolin K and KA 10 mg, taken once daily for 3 months along with diet and exercise, reduces levels of LDL cholesterol by about 28% when compared with diet and exercise alone in patients with hypercholesterolemia (97625). It is possible that any benefit of this product is due to the monacolin content.
• Hyperlipoproteinemia. It is unclear if oral milk thistle is beneficial in patients with hyperlipoproteinemia secondary to liver disease. Details: One very small crossover study shows that taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 420 mg orally daily for 7 months does not significantly improve cholesterol levels in patients with hyperlipoproteinemia secondary to liver disease when compared with placebo (63255).
• Hypoxic liver injury. It is unclear if oral milk thistle is beneficial for reducing liver injury in patients with hypoxia. Details: Preliminary clinical research in patients presenting to the emergency department with hypoxia shows that taking a milk thistle extract of silymarin 280 mg every 8 hours for 3 days reduces markers of liver injury, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT), when compared with placebo (103871).
• Infertility. It is unclear if oral milk thistle is beneficial for patients undergoing in vitro fertilization. Details: Preliminary clinical research shows that taking a milk thistle extract of silymarin 70 mg orally three times daily in combination with human chorionic gonadotropin (HCG) lowers the proportion of early and total apoptosis of follicle cells during in vitro fertilization due to male infertility. However, it does not have an effect on the number of oocytes retrieved or the thickness of the endometrium when compared with HCG plus placebo (63227).
• Lactation. It is unclear if oral milk thistle is beneficial for increasing milk production. Details: A small clinical study shows that taking a milk thistle extract standardized to 60% silymarin (BIO-C, Milte Italia S.r.l.) 240 mg twice daily for 4 weeks does not increase milk production when compared with placebo in mothers of preterm newborns (95027).
• Melasma. It is unclear if topical milk thistle is beneficial in patients with melasma. Details: Preliminary clinical research in adults with melasma shows that applying silymarin 1.4% cream twice daily for 3 months moderately improves melasma appearance scores when compared to baseline. These improvements were similar to hydroquinone cream 2% (110489). One small clinical trial in females with melasma shows that application of silymarin 1.4% cream twice daily to the affected area for 3 months is as effective for improving melasma area and severity as a specific type of laser therapy (low fluence Q switched ND:YAG 1064 nm) (105791).
• Menopausal symptoms. It is unclear if oral milk thistle reduces menopausal symptoms such as hot flashes. Details: One small clinical study in postmenopausal patients shows that taking milk thistle fruit extract 200 mg, containing 80% silymarin, twice daily for 8 weeks seems to reduce the number and severity of daily hot flashes and overall climacteric symptoms when compared with taking placebo (105053). This finding is limited by incomplete reporting and potentially inadequate blinding. Other preliminary clinical research has evaluated milk thistle in combination with black cohosh, dong quai, red clover, American ginseng, and chasteberry (Phyto-Female, SupHerb), with some evidence of benefit for reducing hot flashes and night sweats. (19552).
• Metabolic syndrome. Oral silymarin, a constituent of milk thistle, seems to improve some of the laboratory abnormalities associated with metabolic syndrome. Details: A meta-analysis of 11 low-quality clinical trials in adults with metabolic syndrome, conducted in Asia and Africa, shows that silymarin, 140-2100 mg daily for 45 days to 12 months, modestly reduces fasting blood glucose, glycated hemoglobin, total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels, and increases high-density lipoprotein cholesterol levels, when compared with placebo (107374).
• Multiple sclerosis (MS). Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with MS shows that taking a supplement containing a milk thistle extract of silymarin 150 mg in combination with ferulic acid, gamma-oryzanol, and apigenin twice daily for 3-24 months may stabilize clinical symptoms of MS when compared to baseline (63223). It is unclear if this effect is due to milk thistle, other ingredients, or the combination.
• Nonalcoholic fatty liver disease (NAFLD). Small clinical studies suggest that oral milk thistle extracts of silymarin may slightly improve markers of liver function patients with NAFLD. Details: Two meta-analyses of small clinical trials in patients with NAFLD show that taking milk thistle products containing a total of silymarin 140-2100 mg daily, either alone or in combination with other ingredients, for 8-48 weeks reduces aspartate aminotransferase (AST) by 7 IU/L and alanine aminotransferase (ALT) by 9-15 IU/L, but does not affect weight or lipid levels, when compared with control (97622,105051). However, these changes in liver enzymes may not be clinically impactful and some experts note that serum AST levels do not reliably reflect the spectrum of liver histology in patients with NAFLD (98130). Preliminary clinical research in adults with NAFLD and a body-mass index (BMI) of at least 35 kg/m2 shows that taking milk thistle extract 140 mg 4 times daily for 8 weeks, in addition to lifestyle modifications, reduces BMI by approximately 1 kg/m² when compared with placebo with lifestyle modifications (108657). However, another small clinical trial in adults with NAFLD and a BMI of at least 40 kg/m2 shows that taking a specific silymarin product (Livergol, Goldaru Pharmaceuticals) 140 mg three times daily for 4 weeks did not reduce BMI or improve liver enzymes, such as AST and ALT, when compared with placebo (110484). One small clinical study in patients with NAFLD shows that taking a specific combination product (Eurosil 85, MEDAS SL) containing milk thistle extract standardized to silymarin 540 mg and vitamin E 36 mg daily for 3 months, in addition to following a low-calorie diet, does not appear to improve NAFLD-Fibrosis score or fatty liver index (FLI) when compared with following a low-calorie diet alone (96261).
• Nonalcoholic steatohepatitis (NASH). It is unclear if oral milk thistle is beneficial in patients with NASH. Details: Clinical research in patients with NASH shows that taking a milk thistle extract of silymarin 700 mg three times daily for 48 weeks improves fibrosis in more patients when compared with placebo (96107). However, there is no significant between-group difference in global histological improvement with this product (96107) or with a specific silymarin product (Legalon, Rottapharm Madaus, Mylan) 420 or 700 mg three times daily for 48-50 weeks (101150).
• Obsessive-compulsive disorder (OCD). It is unclear if oral milk thistle is beneficial in patients with OCD. Details: Preliminary clinical research shows that taking milk thistle leaf extract 200 mg orally three times daily for 8 weeks has a limited effect on OCD symptom scores when compared to baseline, but does not provide any benefit over fluoxetine 10 mg three times daily (63219).
• Parkinson disease. Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a supplement containing a milk thistle extract of silymarin 150 mg in combination with ferulic acid, gamma-oryzanol, and apigenin orally twice daily for 3 months to 24 months may stabilize clinical symptoms in patients with Parkinson disease when compared to baseline (63223). It is unclear if this effect is due to milk thistle, other ingredients, or the combination.
• Postpartum complications. It is unclear if topical milk thistle is beneficial in postpartum patients with an episiotomy. Details: Preliminary clinical research in postpartum patients shows that applying milk thistle 3% in Eucerin ointment twice daily to the suture site for 10 days reduces episiotomy pain and improves the healing rate when compared with placebo. The milk thistle product was prepared with an ethanolic extract of the seeds to provide 1.53% silybin (107373).
• Prostate cancer. Oral milk thistle has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with a history of prostate cancer who have had radiotherapy or radical prostatectomy shows that taking a dietary supplement containing a milk thistle extract of silymarin 160 mg, soy isoflavones (Novasoy, ADM) 62.5 mg, lycopene (Lyc-O-Mato, LycoRed Natural Products Industries, Ltd.) 15 mg, vitamins, minerals, and antioxidants orally daily for 10 weeks increases the time it takes for prostate-specific antigen (PSA) levels to double by 2.6-fold when compared with placebo (60361).
• Radiation dermatitis. It is unclear if topical milk thistle is beneficial in patients with dermatitis due to radiation. Details: Preliminary clinical research in females with breast cancer undergoing radiotherapy shows that applying a specific topical product containing a milk thistle extract of silymarin (Leviaderm, Madaus GmbH) significantly reduces the incidence of radiation dermatitis and prolongs the time to the onset of radiation dermatitis when compared with applying a panthenol-containing cream (63239).
• Radiation mucositis. It is unclear if oral milk thistle is beneficial for preventing or treating mucositis due to radiation. Details: One small clinical study in patients with head and neck cancer receiving radiotherapy for the first time shows that taking a specific product containing a milk thistle extract of silymarin (Livergol, Goldaru Pharmaceutical Company), 140 mg three times daily starting from the first day of radiotherapy and continuing for 6 weeks thereafter, reduces the severity and prolongs the time to onset of radiation-induced mucositis when compared with placebo (95021).
• Toxin-induced liver damage. Most small clinical studies suggest that oral milk thistle extracts or constituents may reduce liver injury in people exposed to some, but not all, toxins and medications known to cause liver damage. Details: Taking a milk thistle extract containing 70% to 80% silymarin (Legalon, Madaus GmbH) 420 mg orally daily for up to one month improves liver function tests (LFTs) in people with abnormal LFTs due to chronic occupational exposure to paints or organic solvents such as toluene or xylene (2614,63280). Milk thistle extract has also shown some benefit for reducing drug-induced liver injury (DILI). In patients on isotretinoin therapy for acne, taking a specific milk thistle extract containing silymarin (Livergol, Goldaru Pharmaceutical Company) 140 mg daily for 30 days improves LFTs when compared with placebo (102852). A small clinical study in patients with relapsing-remitting multiple sclerosis who were initiating therapy with fingolimod shows that taking a specific milk thistle extract (Livergol, Goldaru Pharmaceutical Company) containing silymarin 140 mg daily for 6 months prevents fingolimod-induced LFT elevations when compared with placebo (105794). In patients receiving treatment for tuberculosis with rifampin, isoniazid, pyrazinamide, ethambutol, and streptomycin, taking the milk thistle constituent silibinin 70 mg orally three times daily for 6-12 months reduces the rate of liver toxicity to 14% compared with 53% in patients taking glucuronolactone 200 mg orally three times daily (63224). Additionally, in patients receiving standard treatment for tuberculosis with isoniazid, rifampicin, pyrazinamide, and ethambutol, taking a milk thistle extract of silymarin 140 mg orally three times daily for 4 weeks decreases the risk of DILI by 28% when compared with placebo. About 1 in every 4 patients who take silymarin for 4 weeks would avoid DILI (95024). A small clinical study in Iran, also in adults receiving standard treatment for tuberculosis, shows that taking a milk thistle extract of silymarin 150 mg twice daily for 2 weeks modestly improves LFTs when compared with control. None of the 16 patients in the silymarin group developed DILI compared with 2 of 21 patients in the control group; however, this finding was not statistically significant (112230). The interpretation of these findings is limited by the short study duration. However, taking a milk thistle extract of silymarin 420 mg orally daily for 3 months does not seem to prevent liver toxicity associated with tacrine (Cognex) therapy in people with Alzheimer disease (63140). Other research in people with elevated LFTs due to long-term therapy with phenothiazine or butyrophenone antipsychotic medications shows that taking silymarin 800 mg orally daily for 3 months also does not improve LFTs when compared with placebo (63344). A retrospective study in patients with DILI of various offending agents has also found that taking a milk thistle extract, containing a median of 450 mg silybin daily for 24 days is associated with 1.7-2.8 times higher likelihood of LFT normalization when compared with control (110485).
• Trichotillomania. It is unclear if oral milk thistle is beneficial in patients with this condition. Details: Preliminary clinical research in patients 12-65 years of age shows that taking milk thistle 150 mg twice daily for 2 weeks, and then 300 mg twice daily for 4 weeks, does not improve symptoms of trichotillomania when compared with placebo (99426).
• Ulcerative colitis. It is unclear if oral milk thistle is beneficial in patients with this condition. Details: Preliminary clinical research in patients 16-75 years of age shows that taking a specific milk thistle extract of silymarin (Livergol, Goldaru Pharmaceutical Company) 140 mg daily for 6 months, in conjunction with standard medications, decreases disease activity and helps maintain remission when compared with placebo in patients with ulcerative colitis (95029).
• Vitiligo. It is unclear if oral milk thistle reduces the severity of this condition. Details: Preliminary clinical research in a small number of patients with vitiligo shows that taking a specific milk thistle extract containing silymarin (Livergol, Goldaru Pharmaceutical Company) 140 mg twice daily along with phototherapy for 3 months does not improve the severity of vitiligo when compared with phototherapy plus placebo (102851). More evidence is needed to rate milk thistle for these uses.

(Read more about MILK THISTLE)

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). 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). Advise patients not to consume more than the recommended daily intake of 1000-1200 mg per day and to consider total calcium intake from both dietary and supplemental sources (17484). Also, advise patients taking calcium supplements to take calcium along with vitamin D (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). 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). Advise patients to not consume more than the recommended daily intake of 1000-1200 mg per day and to consider total calcium intake from both dietary and supplemental sources (17484). Also, advise patients taking calcium supplements to take calcium along with vitamin D (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).

(Read more about CALCIUM)

LIKELY SAFE ...when used orally and appropriately. A specific milk thistle extract standardized to contain 70% to 80% silymarin (Legalon, Madaus GmbH) has been safely used in doses up to 420 mg daily for up to 4 years (2613,2614,2616,7355,63210,63212,63278,63280,63299,63340)(88154,97626,105792). Higher doses of up to 2100 mg daily have been safely used for up to 48 weeks (63251,96107,101150). Another specific milk thistle extract of silymarin (Livergol, Goldaru Pharmaceutical Company) has been safely used at doses of 140 mg daily for up to 6 months and doses of 420 mg daily for up to 6 weeks (95021,95029,102851,102852,105793,105794,105795). Some isolated milk thistle constituents also appear to be safe. Silibinin (Siliphos, Thorne Research) has been used safely in doses up to 320 mg daily for 28 days (63218). Some combination products containing milk thistle and other ingredients also appear to be safe. A silybin-phosphatidylcholine complex (Silipide, Inverni della Beffa Research and Development Laboratories) has been safely used in doses of 480 mg daily for 7 days (7356) and 240 mg daily for 3 months (63320). Tree turmeric and milk thistle capsules (Berberol, PharmExtracta) standardized to contain 60% to 80% silybin have been safely used twice daily for up to 12 months (95019,96140,96141,96142,97624,101158).

POSSIBLY SAFE ...when used topically and appropriately, short-term. A milk thistle extract cream standardized to silymarin 0.25% (Leviaderm, Madaus GmbH) has been used safely throughout a course of radiotherapy (63239). Another milk thistle extract cream containing silymarin 1.4% has been used with apparent safety twice daily for 3 months (105791,110489). A cream containing milk thistle fruit extract 25% has been used with apparent safety twice daily for up to 12 weeks (111175). A milk thistle extract gel containing silymarin 1% has been used with apparent safety twice daily for 9 weeks (95022). There is insufficient reliable information available about the safety of intravenous formulations of milk thistle or its constituents.

PREGNANCY AND LACTATION:
While research in an animal model shows that taking milk thistle during pregnancy and lactation does not adversely impact infant development (102850), there is insufficient reliable information available about its safety during pregnancy or lactation in humans; avoid using.

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. A milk thistle extract 140 mg three times daily has been used with apparent safety for up to 9 months (88154,98452). A specific product containing the milk thistle constituent silybin (Siliphos, Thorne Research Inc.) has been used with apparent safety in doses up to 320 mg daily for up to 4 weeks in children one year of age and older (63218).

(Read more about MILK THISTLE)

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.

(Read more about CALCIUM)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Taking milk thistle with antidiabetes drugs may increase the risk of hypoglycemia.  Details Clinical research shows that milk thistle extract, alone or along with tree turmeric extract, can lower blood glucose levels and glycated hemoglobin (HbA1c) in patients with type 2 diabetes, including those already taking antidiabetes drugs (15102,63190,63314,63318,95019,96140,96141,97624,97626).

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might inhibit CYP2B6.  Details An in vitro study shows that silybin, a constituent of milk thistle, binds to and noncompetitively inhibits CYP2B6. Additionally, silybin might downregulate the expression of CYP2B6 by decreasing mRNA and protein levels (112229).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = B It is unclear if milk thistle inhibits CYP2C9; research is conflicting.  Details In vitro research suggests that milk thistle might inhibit CYP2C9 (7089,17973,17976). However, contradictory clinical research shows that milk thistle extract does not inhibit CYP2C9 or significantly affect levels of the CYP2C9 substrate tolbutamide (13712,95026). Differences in results could be due to differences in dosages or formulations utilized (95026).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = D It is unclear if milk thistle inhibits CYP3A4; research is conflicting.  Details While laboratory research shows conflicting results (7318,17973,17975,17976), pharmacokinetic research shows that taking milk thistle extract 420-1350 mg daily does not significantly affect the metabolism of the CYP3A4 substrates irinotecan, midazolam, or indinavir (8234,17974,93578,95026).

ESTROGENS Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might interfere with estrogen therapy through competition for estrogen receptors.  Details Animal research suggests that a milk thistle extract of silymarin binds to estrogen receptor beta (93025,93026).

GLUCURONIDATED DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might affect the clearance of drugs that undergo glucuronidation.  Details Laboratory research shows that milk thistle constituents inhibit uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation (7318,17973). Theoretically, this could decrease the clearance and increase levels of glucuronidated drugs. Other laboratory research suggests that a milk thistle extract of silymarin might inhibit beta-glucuronidase (7354), although the significance of this effect is unclear.

HMG-CoA REDUCTASE INHIBITORS ("Statins") Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, milk thistle might interfere with statin therapy by decreasing the activity of organic anion transporting polypeptide 1B1 (OATB1B1) and inhibiting breast cancer resistance protein (BCRP).  Details Preliminary evidence suggests that a milk thistle extract of silymarin can decrease the activity of the OATP1B1, which transports HMG-CoA reductase inhibitors into the liver to their site of action. The silibinin component also inhibits BCRP, which transports statins from the liver into the bile for excretion. However, in a preliminary study in healthy males, silymarin 140 mg three times daily had no effect on the pharmacokinetics of a single 10 mg dose of rosuvastatin (16408).

INDINAVIR (Crixivan) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, milk thistle may induce cytochrome P450 3A4 (CYP3A4) enzymes and increase the metabolism of indinavir; however, results are conflicting.  Details One pharmacokinetic study shows that taking milk thistle (Standardized Milk Thistle, General Nutrition Corp.) 175 mg three times daily in combination with multiple doses of indinavir 800 mg every 8 hours decreases the mean trough levels of indinavir by 25% (8234). However, results from the same pharmacokinetic study show that milk thistle does not affect the overall exposure to indinavir (8234). Furthermore, two other pharmacokinetic studies show that taking specific milk thistle extract (Legalon, Rottapharm Madaus; Thisilyn, Nature's Way) 160-450 mg every 8 hours in combination with multiple doses of indinavir 800 mg every 8 hours does not reduce levels of indinavir (93578).

LEDIPASVIR Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might increase the levels and clinical effects of ledipasvir.  Details Animal research in rats shows that milk thistle increases the area under the curve (AUC) for ledipasvir and slows its elimination (109505).

MORPHINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of milk thistle with morphine might affect serum levels of morphine and either increase or decrease its effects.  Details Animal research shows that milk thistle reduces serum levels of morphine by up to 66% (101161). In contrast, laboratory research shows that milk thistle constituents inhibit uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation (7318,17973). Theoretically, this could decrease the clearance and increase morphine levels. The effect of taking milk thistle on morphine metabolism in humans is not known.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, milk thistle might increase the absorption of P-glycoprotein substrates. However, this effect does not seem to be clinically significant.  Details Although in vitro research shows that milk thistle can inhibit P-glycoprotein activity (95019), clinical research does not agree. A small pharmacokinetic study in healthy volunteers shows that taking milk thistle (Enzymatic Therapy Inc.) 900 mg, standardized to 80% silymarin, in 3 divided doses daily for 14 days does not affect absorption of digoxin, a P-glycoprotein probe substrate (35825).

RALOXIFENE (Evista) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might decrease the clearance and increase levels of raloxifene.  Details Laboratory research suggests that the milk thistle constituents silibinin and silymarin inhibit the glucuronidation of raloxifene in the intestines (93024).

SIROLIMUS (Rapamune) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Milk thistle might decrease the clearance of sirolimus.  Details Pharmacokinetic research shows that a milk thistle extract of silymarin decreases the apparent clearance of sirolimus in hepatically impaired renal transplant patients (19876). It is unclear if this interaction occurs in patients without hepatic impairment.

SOFOSBUVIR (Solvaldi) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might decrease the levels and clinical effects of sofosbuvir.  Details Animal research in rats shows that milk thistle reduces the metabolism of sofosbuvir, as well as the hepatic uptake of its active metabolite (109505).

TAMOXIFEN (Nolvadex) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, the milk thistle constituent silibinin might increase tamoxifen levels and interfere with its conversion to an active metabolite.  Details Animal research suggests that the milk thistle constituent silibinin might increase plasma levels of tamoxifen and alter its conversion to an active metabolite. The mechanism appears to involve inhibition of pre-systemic metabolism of tamoxifen by cytochrome P450 (CYP) 2C9 and CYP3A4, and inhibition of P-glycoprotein-mediated efflux of tamoxifen into the intestine for excretion (17101). Whether this interaction occurs in humans is not known.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, milk thistle might increase the effects of warfarin.  Details In one case report, a man stabilized on warfarin experienced an increase in INR from 2.64 to 4.12 after taking a combination product containing milk thistle 200 mg daily, as well as dandelion, wild yam, niacinamide, and vitamin B12. Levels returned to normal after stopping the supplement (101159). Although a direct correlation between milk thistle and the change in INR cannot be confirmed, some in vitro research suggests that milk thistle might inhibit cytochrome P450 2C9 (CYP2C9), an enzyme involved in the metabolism of various drugs, including warfarin (7089,17973,17976).

(Read more about MILK THISTLE)

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).

(Read more about CALCIUM)

General ...Orally, milk thistle is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal bloating, diarrhea, dyspepsia, flatulence, and nausea. However, these adverse effects do not typically occur at a greater frequency than with placebo.
Serious Adverse Effects (Rare):
Orally: Allergic reactions, including anaphylaxis, have been reported.

Dermatologic ...Orally, milk thistle may cause allergic reactions including urticaria, eczema, skin rash, and anaphylaxis in some people (6879,7355,8956,63210,63212,63238,63251,63315,63325,95029). Allergic reactions may be more likely to occur in patients sensitive to the Asteraceae/Compositae family (6879,8956). A case report describes a 49-year-old female who developed clinical, serologic, and immunopathologic features of bullous pemphigoid after taking milk thistle orally for 6 weeks. Symptoms resolved after treatment with prednisone and methotrexate (107376). Topically, milk thistle can cause erythema (110489).

Gastrointestinal ...Mild gastrointestinal symptoms have been reported, including nausea, vomiting, bloating, diarrhea, epigastric pain, abdominal colic or discomfort, dyspepsia, dysgeusia, flatulence, constipation, and loss of appetite (2616,6879,8956,13170,63140,63146,63160,63210,63218,63219)(63221,63244,63247,63250,63251,63320,63321,63323,63324,63325)(63327,63328,95024,95029,107374). There is one report of a 57-year-old female with sweating, nausea, colicky abdominal pain, diarrhea, vomiting, weakness, and collapse after ingesting milk thistle; symptoms subsided after 24-48 hours without medical treatment and recurred with re-challenge (63329).

Musculoskeletal ...In one clinical study three patients taking milk thistle 200 mg orally three times daily experienced tremor; the incidence of this adverse effect was similar for patients treated with fluoxetine 10 mg three times daily (63219).

(Read more about MILK THISTLE)