| Ingredients | Each Tablet Contains |
|---|---|
|
(Vitamin B1)
|
100 mg |
|
(Vitamin B2)
|
100 mg |
| 100 mg | |
| 100 mg | |
| 400 mcg | |
| 100 mcg | |
| 100 mcg | |
| 100 mg | |
| 10 mg | |
| 10 mg | |
| 10 mg |
Calcium D-Pantothenate (Alt. Name: Ca D-Pantothenate, Ca Pantothenate, Calcium Pantothenate), Calcium Sulfate (Alt. Name: Ca Sulfate), Thiamine Mononitrate, Pyridoxine Hydrochloride (Alt. Name: Pyridoxine HCl), Riboflavin, Stearic Acid (Alt. Name: C18:0), Niacinamide, Hydroxypropyl Methylcellulose, Microcrystalline Cellulose, Silicon Dioxide (Alt. Name: SiO2), Biotin, Cyanocobalamin, Inositol, Choline Bitartrate, Para-Amino Benzoic Acid, Magnesium Stearate, Silicon Dioxide, Colloidal, Brewer's Yeast, Folic Acid, Polyethylene Glycol, Carnauba Wax, Alfalfa powder, Watercress powder
Below is general information about the effectiveness of the known ingredients contained in the product Natural Complex B B100 Formula. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
Below is general information about the safety of the known ingredients contained in the product Natural Complex B B100 Formula. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
LIKELY SAFE ...when used orally and appropriately. Biotin has been safely used in doses up to 300 mg daily for up to 6 months. A tolerable upper intake level (UL) has not been established (1900,6243,95662,102965). ...when applied topically as cosmetic products at concentrations of 0.0001% to 0.6% biotin (19344).
POSSIBLY SAFE ...when used intramuscularly and appropriately (8468,111366).
CHILDREN: LIKELY SAFE
when used orally and appropriately.
Biotin has been safely used at adequate intake doses of 5-25 mcg daily for up to 6 months (173,6243,19347,19348,111365). A tolerable upper intake level (UL) has not been established.
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately.
Biotin has been safely used at the adequate intake (AI) dose of 30 mcg daily during pregnancy and 35 mcg daily during lactation. It has also been used in supplemental doses of up to 300 mcg daily (6243,7878). A tolerable upper intake level (UL) has not been established.
LIKELY SAFE ...when used orally and appropriately. Choline is safe in adults when taken in doses below the tolerable upper intake level (UL) of 3.5 grams daily (3094) ...when used intravenously and appropriately. Intravenous choline 1-4 grams daily for up to 24 weeks has been used with apparent safety (5173,5174).
POSSIBLY UNSAFE ...when used orally in doses above the tolerable upper intake level (UL) of 3. 5 grams daily. Higher doses can increase the risk of adverse effects (3094).
CHILDREN: LIKELY SAFE
when used orally and appropriately (3094).
Choline is safe in children when taken in doses below the tolerable upper intake level (UL), which is 1 gram daily for children 1-8 years of age, 2 grams daily for children 9-13 years of age, and 3 grams daily for children 14-18 years of age (3094).
CHILDREN: POSSIBLY UNSAFE
when used orally in doses above the UL.
High doses can increase the risk of adverse effects (3094).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately.
Choline is safe when taken in doses below the tolerable upper intake level (UL), which is 3 grams daily during pregnancy and lactation in those up to 18 years of age and 3.5 grams daily for those 19 years and older (3094,92114). There is insufficient reliable information available about the safety of choline used in higher doses during pregnancy and lactation.
LIKELY SAFE ...when used orally or parenterally and appropriately. Folic acid has been safely used in amounts below the tolerable upper intake level (UL). The UL for folic acid is based only on supplemental folic acid and is expressed in mcg folic acid. Dietary folate is not included in UL calculations, as dietary folate consumption has not been associated with adverse effects. The UL for folic acid in adults is 1000 mcg (6241). In cases of megaloblastic anemia resulting from folate deficiency or malabsorption disorders such as sprue, oral doses of 1-5 mg per day can also be used safely until hematologic recovery is documented, as long as vitamin B12 levels are routinely measured (6241,7725,8739).
POSSIBLY SAFE ...when L-5-methyltetrahydrofolate (L-5-MTHF), the reduced form of folate, is used orally and appropriately, short-term. L-5-MTHF has been used with apparent safety at a dose of 416 mcg daily for 16 weeks (104913,104914) and a dose of 113 mcg daily for 24 weeks (104920). A specific L-5-MTHF product (Metafolin, Eprova) has been used with apparent safety at a dose of 1.3 mg daily for 12 weeks (104912).
POSSIBLY UNSAFE ...when used orally in large doses, long-term. Clinical research shows that taking folic acid daily in doses of 800 mcg to 1200 mcg for 3-10 years significantly increases the risk of developing cancer and adverse cardiovascular effects compared to placebo (12150,13482,16822,17041). Doses above 1 mg per day should also be avoided if possible to prevent precipitation or exacerbation of neuropathy related to vitamin B12 deficiency (6241,6242,6245). However, there is contradictory evidence suggesting that higher doses may not be harmful. There is some evidence that doses of 5 mg per day orally for up to 4 months can be used safely if vitamin B12 levels are routinely measured (7725). Also, other clinical research suggests that folic acid supplementation at doses up to 5 mg, usually in combination with vitamin B12, does not increase the risk of cancer when taken for 2-7 years (91312). Very high doses of 15 mg per day can cause significant central nervous system (CNS) and gastrointestinal side effects (505).
CHILDREN: LIKELY SAFE
when used orally and appropriately.
Folic acid has been safely used in children in amounts below the tolerable upper intake level (UL). The ULs for folic acid are based only on supplemental folic acid and are expressed in mcg folic acid. Dietary folate is not included in UL calculations, as dietary folate consumption has not been associated with adverse effects. The UL for children is: 1-3 years of age, 300 mcg; 4-8 years of age, 400 mcg; 9-13 years of age, 600 mcg; 14-18 years of age, 800 mcg (6241).
CHILDREN: POSSIBLY SAFE
when L-5-methyltetrahydrofolate (L-5-MTHF), the reduced form of folate, is used orally and appropriately.
One clinical study in infants aged 27 days and younger shows that consuming a formula containing L-5-MTHF (Metafolin, Merck & Cie) 10.4 mcg/100 mL daily has been used with apparent safety for up to 12 weeks (104918).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately.
Folic acid 300-400 mcg is commonly used during pregnancy for prevention of neural tube defects (8739). Miscarriage rates and negative impacts on fetal growth have not been shown to increase with peri-conception supplemental folic acid intakes of 4 mg per day (91320,91322). However, other research shows that taking more than 5 mg per day during pregnancy may reduce development of cognitive, emotional, and motor skills in infants (91318). Also, the tolerable upper intake level (UL) of folic acid for pregnant or lactating women is 800 mcg daily for those 14-18 years of age and 1000 mcg daily for those 19 years and older (6241).
PREGNANCY AND LACTATION: POSSIBLY SAFE
when L-5-methyltetrahydrofolate (L-5-MTHF), the reduced form of folate, is used orally and appropriately, short-term.
L-5-MTHF has been used with apparent safety at a dose of 416 mcg daily for 16 weeks during lactation. Compared to folic acid, this form seems to further increase the folate concentration of red blood cells, but not breast milk (104913,104914).
POSSIBLY SAFE ...when used orally and appropriately, short-term. Inositol has been used with apparent safety in doses up to 18 grams daily for up to 6 weeks or 6 grams daily for 10 weeks (2184,2185,2187,95089). Myo-inositol 4 grams daily has also been used with apparent safety for 6 months (95085). There is insufficient reliable information available about the safety of inositol when used topically.
CHILDREN: POSSIBLY SAFE
when used orally and appropriately.
Inositol 80 mg/kg (maximum 2 grams) has been taken daily for up to 12 weeks in children aged 5-12 years (95092). ...when used enterally or intravenously and appropriately in premature infants for treating acute respiratory distress syndrome for up to 10 days (2191,2192,91546,91551).
CHILDREN: POSSIBLY UNSAFE
when used enterally or intravenously for extended durations in premature infants.
A large clinical study in infants born at less than 28 weeks' gestation found that myo-inositol 40 mg/kg, given intravenously and then enterally every 12 hours for up to 10 weeks, was associated with a small increased risk of death (98946). Long-term follow-up until 24 months corrected age confirms that the initial increase in mortality rate in the myo-inositol group remained stable; however, there was no difference in a composite outcome of death or survival with moderate or severe neurodevelopmental impairment, as well as no difference in the risk of retinopathy of prematurity, between those who received myo-inositol or control (108819).
PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term.
Myo-inositol has been used with apparent safety in amounts up to 4000 mg daily during pregnancy (91548,95082,104688).
LACTATION:
Insufficient reliable information available; avoid using.
Breast milk is rich in endogenous inositol (2138); however, the effects of exogenously administered inositol are not known.
LIKELY SAFE ...when niacin is taken in food or as a supplement in amounts below the tolerable upper intake level (UL) of 30 mg daily for adults 18 years of age and 35 mg daily for adults 19 years and older (6243). ...when prescription products are used orally and appropriately in doses of up to 2 grams daily (12033). CHILDREN:
LIKELY SAFE ...when used orally in amounts that do not exceed the tolerable upper intake level (UL). The ULs of niacin for children are: 1-3 years of age, 10 mg daily; 4-8 years of age, 15 mg daily; 9-13 years of age, 20 mg daily; 14-18 years of age, 30 mg daily (6243).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts that do not exceed the tolerable upper intake level (UL).
The UL of niacin during pregnancy and lactation is 30 mg daily for 14-18 years of age and 35 mg daily for 19 years and older (6243).
There is insufficient reliable information available about the safety of larger oral doses of niacin during pregnancy or lactation; avoid using.
LIKELY SAFE ...when used orally and appropriately. The pantothenic acid derivative calcium pantothenate has a generally recognized as safe (GRAS) status for use in food products (111258). While a tolerable upper intake level (UL) has not been established, pantothenic has been used in doses of 10-20 grams daily with apparent safety (15,6243,111258) ...when applied topically and appropriately, short-term. The Cosmetic Ingredient Review Expert Panel has concluded that pantothenic acid and its derivatives are safe for use in cosmetic products in concentrations up to 5.3% (111258). Gels or ointments containing a derivative of pantothenic acid, dexpanthenol, at concentrations of up to 5%, have been used safely for up to 30 days (67802,67806,67817).
POSSIBLY SAFE ...when applied intranasally and appropriately, short-term. A dexpanthenol nasal spray has been used with apparent safety up to four times daily for 4 weeks (67826). ...when applied in the eyes appropriately, short-term. Dexpanthenol 5% eyedrops have been used with apparent safety for up to 28 days (67783). ...when injected intramuscularly and appropriately, short-term. Intramuscular injections of dexpanthenol 500 mg daily for up to 5 days or 250 mg weekly for up to 6 weeks have been used with apparent safety (67822,111366).
CHILDREN: LIKELY SAFE
when used orally and appropriately (15,6243).
Calcium pantothenate is generally recognized as safe (GRAS) when used as a food additive and in infant formula (111258). However, a tolerable upper intake level (UL) has not been established (15,6243). ...when applied topically and appropriately (67795,105190,111262). Infant products containing pantothenic acid and its derivatives have been used safely in concentrations of up to 5% for infant shampoos and 2.5% for infant lotions and oils. The Cosmetic Ingredient Review Expert Panel has concluded that pantothenic acid and derivatives are safe for use in topical infant products. (111258).
PREGNANCY: LIKELY SAFE
when used orally and appropriately.
The daily adequate intake (AI) during pregnancy is 6 mg (3094).
LACTATION: LIKELY SAFE
when used orally and appropriately.
The daily adequate intake (AI) during lactation is 7 mg (3094).
LIKELY SAFE ...when used topically and appropriately. PABA is FDA approved for topical use and there have not been reports of significant toxicity (266,272).
POSSIBLY SAFE ...when used orally and appropriately (10). PABA is an FDA-approved drug, but some potentially serious side effects have been reported (10).
POSSIBLY UNSAFE ...when used orally in high doses. Doses greater than 12 grams per day have been associated with leukopenia (1061).
CHILDREN: LIKELY SAFE
when used topically and appropriately (266,272).
CHILDREN: POSSIBLY SAFE
when used orally and appropriately (10).
PABA is an FDA-approved drug for use in children, but serious side effects have been reported (10).
CHILDREN: POSSIBLY UNSAFE
when used orally in high doses.
Doses greater than 220 mg/kg/day have been associated with fatal toxic effects (1061).
PREGNANCY AND LACTATION: LIKELY SAFE
when used topically and appropriately (266,272).
There is insufficient reliable information available about the safety of the oral use of PABA during pregnancy and breast-feeding; avoid using.
LIKELY SAFE ...when used orally and appropriately. Riboflavin 400 mg daily has been taken for up to 3 months, and 10 mg daily has been taken safely for up to 6 months (4912,91752,105480). A tolerable upper intake level (UL) has not been established (3094,91752,94089).
CHILDREN: LIKELY SAFE
when used orally and appropriately in dietary amounts.
A tolerable upper intake level (UL) has not been established (3094,94089). ...when used orally in higher doses for up to 1 year. Doses of 100-200 mg daily have been used safely for 4-12 months in children ages 9-13 years (71483,105484).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately in dietary amounts.
A tolerable upper intake level (UL) has not been established (3094,94089).
LIKELY SAFE ...when used orally and appropriately. A tolerable upper intake level (UL) has not been established for thiamine, and doses up to 50 mg daily have been used without adverse effects (15,6243). ...when used intravenously or intramuscularly and appropriately. Injectable thiamine is an FDA-approved prescription product (15,105445).
CHILDREN: LIKELY SAFE
when used orally and appropriately in dietary amounts.
A tolerable upper intake level (UL) has not been established for healthy individuals (6243).
PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in dietary amounts of 1.
4 mg daily. A tolerable upper intake level (UL) has not been established for healthy individuals (3094,6243).
LIKELY SAFE ...when used orally, topically, intravenously, intramuscularly, or intranasally and appropriately. Vitamin B12 is generally considered safe, even in large doses (15,1344,1345,1346,1347,1348,2909,6243,7289,7881)(9414,9416,10126,14392,15765,82832,82949,82860,82864,90386)(111334,111551).
PREGNANCY: LIKELY SAFE
when used orally in amounts that do not exceed the recommended dietary allowance (RDA).
The RDA for vitamin B12 during pregnancy is 2.6 mcg daily (6243). There is insufficient reliable information available about the safety of larger amounts of vitamin B12 during pregnancy.
LACTATION: LIKELY SAFE
when used orally in amounts that do not exceed the recommended dietary allowance (RDA).
The RDA of vitamin B12 during lactation is 2.8 mcg daily (6243). There is insufficient reliable information available about the safety of larger amounts of vitamin B12 while breastfeeding.
LIKELY SAFE ...when used orally and appropriately in doses that do not exceed the tolerable upper intake level (UL) of 100 mg daily in the form of pyridoxine for adults (15,6243). ...when used parenterally and appropriately. Injectable vitamin B6 (pyridoxine) is an FDA-approved prescription product (15).
POSSIBLY SAFE ...when used orally and appropriately in doses of 101-200 mg daily (6243,8558).
POSSIBLY UNSAFE ...when used orally in doses at or above 500 mg daily. High doses, especially those exceeding 1000 mg daily or total doses of 1000 grams or more, pose the most risk. However, neuropathy can occur with lower daily or total doses (6243,8195). ...when used intramuscularly in high doses and frequency due to potential for rhabdomyolysis (90795).
CHILDREN: LIKELY SAFE
when used orally and appropriately in doses that do not exceed the tolerable upper intake level (UL) of vitamin B6 in the form of pyridoxine 30 mg daily for children aged 1-3 years, 40 mg daily for 4-8 years, 60 mg daily for 9-13 years, and 80 mg daily for 14-18 years (6243).
CHILDREN: POSSIBLY SAFE
when used orally and appropriately in amounts exceeding the recommended dietary allowance (5049,8579,107124,107125,107135).
CHILDREN: POSSIBLY UNSAFE
when used orally in excessive doses, long-term (6243).
PREGNANCY: LIKELY SAFE
when used orally and appropriately.
A special sustained-release product providing vitamin B6 (pyridoxine) 75 mg daily is FDA-approved for use in pregnancy. Vitamin B6 (pyridoxine) is also considered a first-line treatment for nausea and vomiting in pregnancy by the American College of Obstetrics and Gynecology (111601). However, it should not be used long-term or without medical supervision and close monitoring. The tolerable upper intake level (UL) refers to vitamin B6 in the form of pyridoxine and is 80 mg daily for those aged 14-18 years and 100 mg daily for 19 years and older (6243).
PREGNANCY: POSSIBLY UNSAFE
when used orally in excessive doses.
There is some concern that high-dose maternal vitamin B6 (pyridoxine) can cause neonatal seizures (4609,6397,8197).
LACTATION: LIKELY SAFE
when used orally in doses not exceeding the tolerable upper intake level (UL) of vitamin B6 in the form of pyridoxine 80 mg daily for those aged 14-18 years and 100 mg daily for those 19 years and older.
The recommended dietary allowance (RDA) in lactating women is 2 mg daily (6243). There is insufficient reliable information available about the safety of vitamin B6 when used in higher doses in breast-feeding women.
Below is general information about the interactions of the known ingredients contained in the product Natural Complex B B100 Formula. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, choline might decrease the effects of atropine in the brain.
 Details
Animal research shows that administering choline one hour before administering atropine can attenuate atropine-induced decreases in brain levels of acetylcholine (42240). Theoretically, concomitant use of choline and atropine may decrease the effects of atropine.
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Theoretically, high doses of folic acid might increase the toxicity of 5-fluorouracil.
Details
Increases in gastrointestinal side effects of 5-fluorouracil, such as stomatitis and diarrhea, have been described in two clinical studies when leucovorin, a form of folic acid, was administered with 5-fluorouracil (16845).
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Use of high-dose folic acid might contribute to capecitabine toxicity.
Details
Clinical research suggests that higher serum folate levels are associated with an increased risk for moderate or severe toxicity during capecitabine-based treatment for colorectal cancer (105402). Additionally, in one case report, taking folic acid 15 mg daily might have contributed to increased toxicity, including severe diarrhea, vomiting, edema, hand-foot syndrome, and eventually death, in a patient prescribed capecitabine (16837).
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Folic acid might reduce the efficacy of methotrexate as a cancer treatment when given concurrently.
Details
Methotrexate exerts its cytotoxic effects by preventing conversion of folic acid to the active form needed by cells. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers (9420). Advise cancer patients to consult their oncologist before using folic acid supplements. In patients treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis, folic acid supplements can reduce the incidence of side effects, without reducing efficacy (768,2162,4492,4493,4494,4546,9369).
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Folic acid might have antagonistic effects on phenobarbital and increase the risk for seizures.
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Folic acid might reduce serum levels of phenytoin in some patients.
Details
Folic acid may be a cofactor in phenytoin metabolism (4471). Folic acid, in doses of 1 mg daily or more, can reduce serum levels of phenytoin in some patients (4471,4477,4531,4536). Increases in seizure frequency have been reported. If folic acid supplements are added to established phenytoin therapy, monitor serum phenytoin levels closely. If phenytoin and folic acid are started at the same time and continued together, adverse changes in phenytoin pharmacokinetics are avoided (4471,4472,4473,4531). Note that phenytoin also reduces serum folate levels.
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Folic acid might have antagonistic effects on primidone and increase the risk for seizures.
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Folic acid might antagonize the effects of pyrimethamine.
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Folic acid can antagonize the antiparasitic effects of pyrimethamine against toxoplasmosis and Pneumocystis carinii pneumonia. Folic acid doesn't antagonize the effects of pyrimethamine in the treatment of malaria, because malarial parasites cannot use exogenous folic acid. Use folinic acid as an alternative to folic acid when indicated (9380).
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Theoretically, taking inositol with antidiabetes drugs might increase the risk of hypoglycemia.
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Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Details
Alcohol can exacerbate the flushing and pruritus associated with niacin (4458,11689). Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine (14510). Advise patients to avoid large amounts of alcohol while taking niacin.
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Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Details
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia (4860,4863,12033). Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin (4458). People who have frequent attacks of gout despite uricosuric therapy should avoid niacin (4863).
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Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
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Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Details
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose (4860,4863,11692,11693). In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21% (4860). However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose (12033). In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached (12033,93344). Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added (4458,4860,4863,11689,12033).
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Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
Details
The vasodilating effects of niacin can cause hypotension (4863,12033,93341). Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients (25917).
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Large doses of aspirin might alter the clearance of niacin.
Details
Aspirin is often used with niacin to reduce niacin-induced flushing (4458,11689). Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal (4458,4852,4853,11689). Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45% (14524). This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg (11689,14524).
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Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
Details
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30% (14511).
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Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
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Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Details
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses (4863,11689,11691,25929,25930,25931,113553). Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin (11691,25930,25931,93342,113553).
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Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Details
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins (14508,25918). However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor) (7388,11689,12033,14509).
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Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Details
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia (4863,12033). Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin (4458). People who have frequent attacks of gout despite uricosuric therapy should avoid niacin (4863).
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Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Details
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia (4863,12033). Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin (4458). People who have frequent attacks of gout despite uricosuric therapy should avoid niacin (4863).
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Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Details
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4) (25916,25925,25926,25928). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.
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Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
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Theoretically, concomitant use of PABA and cortisone may increase the effects of cortisone.
Details
Preliminary clinical research shows that PABA decreases the metabolism of cortisone (4488). Dose adjustments of cortisone may be necessary.
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Theoretically, concomitant use of PABA and dapsone may decrease the effects of dapsone.
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Theoretically, concomitant use of PABA and sulfonamide antibiotics inhibits the antibacterial effects of sulfonamide.
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Sulfonamide antibiotics competitively inhibit folic acid synthesis from PABA. Excess PABA may overcome the folate depleting effect of the sulfonamides (10). Avoid concurrent use.
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Theoretically, taking riboflavin with tetracycline antibiotics may decrease the potency of these antibiotics.
Details
In vitro research suggests that riboflavin may inhibit the potency of tetracycline antibiotics (23372). It is not clear if this effect is clinically significant, as this interaction has not been reported in humans.
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Trimethoprim might increase blood levels of thiamine.
Details
In vitro, animal, and clinical research suggest that trimethoprim inhibits intestinal thiamine transporter ThTR-2, hepatic transporter OCT1, and renal transporters OCT2, MATE1, and MATE2, resulting in paradoxically increased thiamine plasma concentrations (111678).
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Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
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Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
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Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure (30859,82959,83093). Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine (83091).
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Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Details
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people (3046).
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High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
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High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
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Below is general information about the adverse effects of the known ingredients contained in the product Natural Complex B B100 Formula. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally and topically, biotin is generally well tolerated.
Most Common Adverse Effects: None.
Gastrointestinal ...Orally, high-dose biotin has been rarely associated with mild diarrhea. Transient mild diarrhea was reported by 2 patients taking biotin 300 mg daily (95662).
Pulmonary/Respiratory ...In one case report in France, a 76-year-old female frequent traveler developed eosinophilic pleuropericarditis after taking biotin 10 mg and pantothenic acid 300 mg daily for 2 months. She had also been taking trimetazidine for 6 years (3914). Whether eosinophilia in this case was related to biotin, pantothenic acid, other substances, or patient-specific conditions is unknown. There have been no other similar reports.
General
...Orally, choline is well tolerated when used appropriately.
Adverse effects have been reported with doses exceeding the tolerable upper intake level (UL) of 3.5 grams daily.
Most Common Adverse Effects:
Orally: Fishy body odor. At high doses of at least 9 grams daily, choline has been reported to cause diarrhea, nausea, salivation, sweating, and vomiting.
Cardiovascular ...Orally, doses of choline greater than 7. 5 grams daily may cause low blood pressure (94648).
Gastrointestinal ...Orally, large doses of choline can cause nausea, vomiting, salivation, and anorexia (42275,91231). Gastrointestinal discomfort has reportedly occurred with doses of 9 grams daily, while gastroenteritis has reportedly occurred with doses of 32 grams daily (42291,42310). Doses of lecithin 100 grams standardized to 3.5% choline have reportedly caused diarrhea and fecal incontinence (42312).
Genitourinary ...Orally, large doses of choline greater than 9 grams daily have been reported to cause urinary incontinence (42291).
Neurologic/CNS ...Orally, high intake of choline may cause sweating due to peripheral cholinergic effects (42275).
Oncologic ...In one population study, consuming large amounts of choline was associated with an increased risk of colorectal cancer in females, even after adjusting for red meat intake (14845). However, more research is needed to confirm this finding.
Psychiatric ...Orally, large doses of choline (9 grams daily) have been associated with onset of depression in patients taking neuroleptics. Further research is needed to clarify this finding (42270).
Other ...Orally, choline intake may cause a fishy body odor due to intestinal metabolism of choline to trimethylamine (42285,42275,42310,92111,92112).
General
...Orally, folic acid is generally well-tolerated in amounts found in fortified foods, as well as in supplemental doses of less than 1 mg daily.
Most Common Adverse Effects:
Orally: At doses of 5 mg daily - abdominal cramps, diarrhea, and rash. At doses of 15 mg daily - bitter taste, confusion, hyperactivity, impaired judgment, irritability, nausea, sleep disturbances.
Serious Adverse Effects (Rare):
Orally: Cancer (long-term use), cardiovascular complications, liver injury, seizures.
All ROAs: Allergic reactions such as bronchospasm and anaphylactic shock.
Cardiovascular ...There is some concern that high oral doses of folic acid might increase the risk of adverse cardiovascular outcomes. Clinical research shows that taking doses of 800 mcg to 1.2 mg/day might increase the risk of adverse cardiovascular events in patients with cardiovascular disease (12150,13482). High doses of folic acid might promote cell growth by providing large amounts of the biochemical precursors needed for cell replication. Overgrowth of cells in the vascular wall might increase the risk of occlusion (12150). Although some research suggests that use of folic acid might increase the need for coronary revascularization, analysis of multiple studies suggests that taking folic acid up to 5 mg/day for up to 24 months does not appear to affect coronary revascularization risk (90798).
Dermatologic ...Orally, folic acid 1-5 mg daily can cause rash (7225,90375,91319). Folic acid 15 mg daily can sometimes cause allergic skin reactions (15).
Gastrointestinal ...Orally, folic acid 5 mg daily can cause abdominal cramps and diarrhea (7225). Folic acid 15 mg daily can sometimes cause nausea, abdominal distention, flatulence, and bitter taste in the mouth (15). In children aged 6-30 months at risk of malnourishment, taking a nutritional supplement (Nutriset Ltd) enriched in folic acid 75-150 mcg daily, with or without vitamin B 12 0.9-1.8 mcg daily, for 6 months increases the likelihood of having persistent diarrhea (90391).
Hepatic ...Liver dysfunction, with jaundice and very high liver enzymes, occurred in a 30-year-old pregnant patient with severe nausea and vomiting taking a folic acid supplement (Folic acid, Nature Made) 400 mcg daily. Based on the timing of ingestion, the lack of other etiological factors, a positive drug-induced lymphocyte stimulation test, and liver function normalization once the folic acid had been stopped, the authors suggest the folic acid supplement was the cause. However, the authors did not determine which substance in the folic acid supplement was responsible and therefore it cannot be determined that folic acid itself was the cause (91309).
Neurologic/CNS ...Orally, folic acid 15 mg daily can sometimes cause altered sleep patterns, vivid dreaming, irritability, excitability, hyperactivity, confusion, and impaired judgment (15). Large doses of folic acid can also precipitate or exacerbate neuropathy in people deficient in vitamin B12 (6243). Use of folic acid for undiagnosed anemia has masked the symptoms of pernicious anemia, resulting in lack of treatment and eventual neurological damage (15). Patients should be warned not to self-treat suspected anemia. There is also some concern that consuming high amounts of folic acid from the diet and/or supplements might worsen cognitive decline in older people. A large-scale study suggests that people over 65 years of age, who consume large amounts of folic acid (median of 742 mcg/day), have cognitive decline at a rate twice as fast as those consuming smaller amounts (median of 186 mcg/day). It's not known if this is directly attributable to folic acid. It is theorized that it could be due to folic acid masking a vitamin B12 deficiency. Vitamin B12 deficiency is associated with cognitive decline (13068). More evidence is needed to determine the significance of this finding. For now, suggest that most patients aim for the recommended folic acid intake of 400 mcg/day.
Oncologic
...There is some concern that high dose folic acid might increase the risk of cancer, although research is unclear and conflicting.
A large-scale population study suggests that taking a multivitamin more than 7 times per week with a separate folic acid supplement significantly increased the risk of prostate cancer (15607). Clinical research also shows that taking folic acid 1 mg daily increase the absolute risk of prostate cancer by 6.4% over a 10-year period when compared with placebo. However, those with a higher baseline dietary intake of folic acid had a lower rate of prostate cancer, but this was not statistically significant. Also, folate and folic acid intake in patients with prostate cancer is not associated with the risk of prostate cancer recurrence after radical prostatectomy (91317). However, it is possible that discrepancies are due to dietary folate versus folic acid intake. Large analyses of population studies suggest that while dietary folate/folic acid is not associated with prostate cancer, high blood folate/folic acid increases the risk of prostate cancer (50411,91316).
Additional clinical research shows that taking folic acid 800 mcg daily, in combination with vitamin B12 400 mcg, significantly increases the risk of developing cancer, especially lung cancer, and all-cause mortality in patients with cardiovascular disease (17041). However, this may be due to vitamin B12, as other observational research found that higher vitamin B12 levels are linked with an increased risk for lung cancer (102383). Meta-analyses of large supplementation trials of folic acid at levels between 0.5-2.5 mg daily also suggest an increased risk of cancer (50497,110318). Also, in elderly individuals, taking folic acid 400 mcg daily with vitamin B12 500 mcg daily increased the risk of cancer. The risk was highest in individuals over 80 years of age and in females and mainly involved gastrointestinal and colorectal cancers (90393).
Not all researchers suspect that high intake of folic acid supplements might be harmful. Some research suggests that increased dietary intake of folic acid, along with other nutrients, might be protective against cancer (16822). A meta-analysis of multiple clinical trials suggests that folic acid supplementation studies with folic acid levels between 500 mcg to 50 mg/day does not increase the risk of general or site-specific cancer for up to 7 years (91312,91321). Also, a post-hoc subgroup analysis of results from clinical research in adults with a history of recent stroke or ischemic attack suggests that taking folic acid, vitamin B12, and vitamin B6 does not increase cancer risk overall, although it was associated with an increased risk of cancer in patients who also had diabetes (90378).
Psychiatric ...Orally, folic acid 15 mg daily can sometimes cause exacerbation of seizure frequency and psychotic behavior (15).
Pulmonary/Respiratory ...Folic acid use in late pregnancy has been associated with an increased risk of persistent and childhood asthma at 3. 5 years in population research (50380). When taken pre-pregnancy or early in pregnancy, population research has not found an association with increased risk of asthma or allergies in childhood (90799,103979). Folic acid use in pregnancy has been associated with a slightly increased risk of wheeze and lower respiratory tract infections up to 18 months of age in population research (50328).
General
...Orally and intravenously, inositol seems to be well tolerated.
Topically, no adverse effects have been reported, although a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Orally: Diarrhea, gas, and nausea.
Gastrointestinal ...Orally, inositol may cause nausea, diarrhea, gas, and gastrointestinal discomfort (10387,11972,91547,91549,95089,95090,95092).
Immunologic ...Orally, inositol in combination with omega-3 fatty acids has been associated with reports of cold and allergy symptoms in children in clinical research (95092).
Musculoskeletal ...Orally, inositol in combination with omega-3 fatty acids has been associated with reports of tics and other musculoskeletal side effects in children in clinical research (95092).
Neurologic/CNS ...Orally, inositol may cause dizziness, tiredness, insomnia, agitation, and headache (10387,11972,95089,95092). In combination with omega-3 fatty acids, inositol has been associated with reports of feelings of thirst in children in clinical research (95092).
Psychiatric ...In one case report, a 36-year-old male with adequately controlled bipolar disorder was hospitalized with symptoms of mania after consuming several cans of an energy drink containing inositol, caffeine, taurine, and other ingredients (Red Bull Energy Drink) over a period of 4 days (14302). It is not known if this is related to inositol, caffeine, taurine, a different ingredient, or a combination of the ingredients.
General
...Orally, niacin is well tolerated in the amounts found in foods.
It is also generally well tolerated in prescription doses when monitored by a healthcare provider.
Most Common Adverse Effects:
Orally: Flushing, gastrointestinal complaints (abdominal pain, constipation, diarrhea, heartburn, nausea, vomiting), and elevated liver enzymes.
Serious Adverse Effects (Rare):
Orally: Hepatotoxicity, myopathy, thrombocytopenia, and vision changes.
Cardiovascular
...Orally, flushing is a common dose-related adverse reaction to niacin.
A large meta-analysis of clinical studies shows that up to 70% of patients may experience flushing (96211). Although flushing can occur with doses of niacin as low as 30 mg daily, it is more common with the larger doses used for treatment of dyslipidemia. The flushing reaction is due to prostaglandin-induced blood vessel dilation and can also include symptoms of burning, tingling, urticaria, erythema, pain, and itching of the face, arms, and chest. There may also be increased intracranial blood flow and headache (4889,26089,93341,104933). Onset is highly variable and ranges from within 30 minutes to as long as 6 weeks after the initial dose (6243). Flushing can be minimized via various strategies, including taking doses with meals, slow dose titration, using extended release formulations, pretreating with non-steroidal anti-inflammatory drugs, taking regular-release niacin with meals, or taking the sustained-release product at bedtime (4852,4853,4854,4857,4858,25922,26073,26084). Flushing often diminishes with continued use but can recur when niacin is restarted after missed doses (4863,6243,26081). The vasodilating effects of niacin can also cause hypotension, dizziness, tachycardia, arrhythmias, syncope, and vasovagal attacks, especially in patients who are already taking antihypertensive drugs (4863,12033,93341,110494).
High doses of niacin can raise homocysteine levels. A 17% increase has been reported with 1 gram daily and a 55% increased has been reported with 3 grams daily. Elevated homocysteine levels are an independent risk factor for cardiovascular disease (490); however, the clinical significance of this effect is unknown. A large-scale study (AIM-HIGH) found that patients receiving extended-release niacin (Niaspan) 1500-2000 mg daily with a statin had an over two-fold increased risk of ischemic stroke (1.6%) when compared with those receiving only simvastatin (0.7%). However, when the risk was adjusted for confounding factors, niacin was not found to be associated with increased stroke risk (17627,93354). A meta-analysis of three clinical trials conducted in approximately 29,000 patients showed a higher risk of mortality in patients taking niacin in addition to a statin when compared with a statin alone. However, with a p-value of 0.05 and confidence interval including 1, the validity of this finding remains unclear (97308).
Endocrine
...Orally, niacin can impair glucose tolerance in a dose-dependent manner.
Dosages of 3-4 grams daily appear to increase blood glucose in patients with or without diabetes, while dosages of 1.5 grams daily or less have minimal effects (12033). Niacin is thought to impair glucose tolerance by increasing insulin resistance or increasing hepatic output of glucose (4863,11692,11693). In patients with diabetes, niacin 4.5 grams daily for 5 weeks has been associated with an average 16% increase in plasma glucose and 21% increase in glycated hemoglobin (HbA1C) (4860). Up to 35% of patients with diabetes may need to increase the dose or number of hypoglycemic agents when niacin is started (4458,4860,4863,11689,12033). Occasionally, severe hyperglycemia requiring hospitalization can occur (11693). In patients with impaired fasting glucose levels, niacin may also increase fasting blood glucose, and adding colesevelam might attenuate this effect (93343).
Although patients without diabetes seem to only experience small and clinically insignificant increases in glucose (4458), niacin might increase their risk of developing diabetes. A meta-analysis of clinical research involving over 26,000 patients shows that using niacin over 5 years is associated with increased prevalence of new onset type 2 diabetes at a rate of 1 additional case of diabetes for every 43 patients treated with niacin (96207). This finding is limited because the individual trials were not designed to assess diabetes risk and the analysis could not be adjusted for confounding factors like obesity. One small clinical study shows that taking extended-release niacin with ezetimibe/simvastatin does not increase the risk of a new diagnosis of diabetes or need for antidiabetic medication when compared with ezetimibe/simvastatin alone after 16 months (93344). This may indicate that the increased risk of developing diabetes is associated with niacin use for more than 16 months.
Niacin therapy has also been linked with hypothyroidism and its associated alterations in thyroid hormone and binding globulin tests (such as decreased total serum thyroxine, increased triiodothyronine, decreased thyroxine-binding globulin levels, and increased triiodothyronine uptake) (25916,25925,25926,25928).
Gastrointestinal ...Orally, large doses of niacin can cause gastrointestinal disturbances including nausea, vomiting, bloating, heartburn, abdominal pain, anorexia, diarrhea, constipation, and activation of peptic ulcers (4458,4863,12033,26083,93341,96211). These effects may be reduced by taking the drug with meals or antacid, and usually disappear within two weeks of continued therapy (4851,26094). Gastrointestinal effects may be more common with time-release preparations of niacin (11691).
Hematologic ...Orally, sustained-release niacin has been associated with cases of reversible coagulopathy, mild eosinophilia, and decreased platelet counts (4818,25915,26097,93340). Also, there have been reports of patients who developed leukopenia while taking niacin for the treatment of hypercholesterolemia (25916).
Hepatic ...Orally, niacin is associated with elevated liver function tests and jaundice, especially with doses of 3 grams/day or more, and when doses are rapidly increased (4458,4863,6243). The risk of hepatotoxicity appears to be higher with slow-release and extended-release products (4855,4856,4863,6243,11691,12026,12033,93342). Niacin should be discontinued if liver function tests rise to three times the upper limit of normal (4863). There are rare cases of severe hepatotoxicity with fulminant hepatitis and encephalopathy due to niacin (4863,6243,11691). In one case, a patient taking extended-release niacin 2500 mg daily for 15 years developed decompensating cirrhosis and was diagnosed with chronic, toxic, metabolic liver injury. Despite medical intervention, the patient died (113553). Also, there is at least one case of niacin-induced coagulopathy resulting from liver injury without liver enzyme changes (93340).
Musculoskeletal ...Orally, niacin has been associated with elevated creatine kinase levels (4818,4888). Also, several cases of niacin-induced myopathy have been reported (26100,26111). Concomitant administration of niacin and HMG-CoA reductase inhibitors may increase the risk of myopathy and rhabdomyolysis (14508,25918,26111); patients should be monitored closely.
Neurologic/CNS ...Orally, high-dose niacin has been associated with cases of neuropsychiatric adverse events such as extreme pain and psychosis. Two 65-year-old males taking niacin orally for 5 months for the treatment of dyslipidemias developed severe dental and gingival pain. The pain was relieved by the discontinuation of niacin. The pain was thought to be due to inflammation and pain referral to the teeth (4862). In one case report, a 52-year-old male with no history of psychiatric illness who initially complained of hot flushes when taking niacin 500 mg daily, presented with an acute psychotic episode involving mania after niacin was increased to 1000 mg daily (93350).
Ocular/Otic ...Orally, chronic use of large amounts of niacin has been associated with dry eyes, toxic amblyopia, blurred vision, eyelid swelling, eyelid discoloration, loss of eyebrows and eyelashes, proptosis, keratitis, macular edema, and cystic maculopathy, which appear to be dose-dependent and reversible (4863,6243,26112).
General
...Orally, pantothenic acid is generally well tolerated.
Topically and intramuscularly, dexpanthenol, a synthetic form of pantothenic acid, seems to be well tolerated.
Most Common Adverse Effects:
Topically: Burning, contact dermatitis, eczema, irritation, and itching related to dexpanthenol.
Cardiovascular ...There is one case of eosinophilic pleuropericardial effusion in a patient taking pantothenic acid 300 mg per day in combination with biotin 10 mg per day for 2 months (3914).
Dermatologic ...Topically, dexpanthenol has been associated with itching, burning, skin irritation, contact dermatitis, and eczema (67779,67781,67788,111258,111262). Three cases of allergic contact dermatitis have been reported (111260,111261).
Gastrointestinal ...Orally, pantothenic acid has been associated with diarrhea (67822,111258).
General
...Orally and topically, PABA is generally well tolerated.
Most Common Adverse Effects:
Orally: Anorexia, dyspepsia, fever, nausea, rash, vomiting.
Topically: Dermatitis, paradoxical photosensitivity.
Serious Adverse Effects (Rare):
Orally: Hepatotoxicity.
Dermatologic ...Topically, PABA can cause contact dermatitis and sometimes paradoxical photosensitivity (272).
Gastrointestinal ...Orally, the most commonly reported side effects of PABA are diarrhea, nausea, vomiting, anorexia, dyspepsia, fever, and rash (1074). PABA should be discontinued if adverse effects prevent the patient from eating (10). In one report, up to 25% of patients discontinued PABA due to intolerance of side effects (1074).
Hematologic ...High dose PABA (up to 48 grams per day) can cause decreased white blood count below 4000 mm3 in approximately 30% of patients (1061).
Hepatic ...Liver toxicity, including fatal hepatitis has been reported in patients taking PABA in high doses (12-48 grams per day) (1061,1094). In one case, 12 grams per day for 2 months caused liver toxicity (1094). Increased liver function tests from PABA have also been noted (1084), and jaundice was reported in one case of treatment with PABA (68049). Despite these reports, a study reviewing the charts of 274 patients with scleroderma who were taking the potassium salt form of PABA as treatment found no evidence of hepatotoxicity (1065).
Immunologic ...Orally, PABA can cause allergic reactions including fever and skin rash (1074).
Neurologic/CNS ...Orally, PABA may cause headaches, which resolve upon discontinuation of treatment (1074).
Other ...Death has been reported in 3 children treated with 24 grams of PABA per day for rheumatic fever or arthritis. At autopsy, all had fatty changes in the liver, kidney, and myocardium (1061). Topical PABA and its derivatives have a tendency to discolor clothing due to a photo-oxidative reaction (68025).
General
...Orally, riboflavin is generally well tolerated.
Most Common Adverse Effects:
Orally: Dose-related nausea and urine discoloration.
Gastrointestinal ...Orally, riboflavin has been associated with rare diarrhea and dose-related nausea (1398,71483). In one clinical study, one subject out of 28 reported having diarrhea two weeks after starting riboflavin 400 mg daily (1398).
Genitourinary ...Orally, high doses of riboflavin can cause bright yellow urine. Furthermore, in one clinical study, one subject out of 28 reported polyuria two weeks after starting riboflavin 400 mg daily (1398,3094).
General
...Orally and parenterally, thiamine is generally well tolerated.
Serious Adverse Effects (Rare):
Parenterally: Hypersensitivity reactions including angioedema and anaphylaxis.
Immunologic
...Orally, thiamine might rarely cause dermatitis and other allergic reactions.
Parenterally, thiamine can cause anaphylactoid and hypersensitivity reactions, but this is also rare (<0.1%). Reported symptoms and events include feelings of warmth, tingling, pruritus, urticaria, tightness of the throat, cyanosis, respiratory distress, gastrointestinal bleeding, pulmonary edema, angioedema, hypotension, and death (15,35585,105445).
In one case report, a 46-year-old female presented with systemic allergic dermatitis after applying a specific product (Inzitan, containing lidocaine, dexamethasone, cyanocobalamin and thiamine) topically by iontophoresis; the allergic reaction was attributed to thiamine (91170).
General
...Orally, intramuscularly, and topically, vitamin B12 is generally well-tolerated.
Most Common Adverse Effects:
Intramuscular: Injection site reactions.
Serious Adverse Effects (Rare):
Intramuscularly: Severe hypokalemia has been rarely linked with correction of megaloblastic anemia with vitamin B12.
Cardiovascular ...In human clinical research, an intravenous loading dose of folic acid, vitamin B6, and vitamin B12, followed by daily oral administration after coronary stenting, increased restenosis rates (12150). Hypertension following intravenous administration of hydroxocobalamin has been reported in human research (82870,82864).
Dermatologic
...Orally or intramuscularly, vitamin B12 can cause allergic reactions such as rash, pruritus, erythema, and urticaria.
Theoretically, allergic reactions might be caused by the cobalt within the vitamin B12 molecule (82864,90373,90381,103974). In one case report, oral methylcobalamin resulted in contact dermatitis in a 59-year-old Japanese female with a cobalt allergy (103974). In another case report, a 69-year-old female developed a symmetrical erythematous-squamous rash for 5 years after oral vitamin B12 supplementation for 10 years. A patch test confirmed that the systemic allergic dermatitis was due to vitamin B12 supplementation, which resolved 3 months after discontinuation (114578).
Vitamin B12 (intramuscular or oral) has also been associated with at least 19 cases of acneiform eruptions which resolved upon discontinuation of vitamin B12 (90365,90369,90388). High-dose vitamin B12 (20 mcg daily) and vitamin B6 (80 mg daily) have been associated with cases of rosacea fulminans characterized by intense erythema with nodules, papules, and pustules. Symptoms may last up to four months after the supplement is stopped and can be treated with systemic corticosteroids and topical therapy (10998,82870,82871).
Gastrointestinal ...Intravenously, vitamin B12 (hydroxocobalamin) 2. 5-10 grams can cause nausea and dysphagia (82864).
Genitourinary ...Intravenously, vitamin B12 (hydroxocobalamin) 5-15 grams has been associated with chromaturia in clinical research (82870,82871,112282,112264).
Hematologic ...According to case report data, the correction of megaloblastic anemia with vitamin B12 may result in fatal hypokalemia (82914).
Musculoskeletal ...According to case report data, correction of megaloblastic anemia with vitamin B12 has precipitated gout in susceptible individuals (82879).
Neurologic/CNS ...Treatment with vitamin B12 has been rarely associated with involuntary movements in infants with vitamin B12 deficiency (90370,90385,90397). In some cases these adverse reactions were misdiagnosed as seizures or infantile tremor syndrome (90370,90385). These adverse reactions presented 2-5 days after treatment with vitamin B12 and resolved once vitamin B12 was discontinued (90370,90385,90397).
Oncologic ...Although some epidemiological research disagrees (9454), most research has found that elevated plasma levels of vitamin B12 are associated with an increased risk of various types of cancer, including lung and prostate cancers and solid tumors (50411,102383,107743). One study found, when compared with blood levels of vitamin B12 less than 1000 ng/mL, plasma vitamin B12 levels of at least 1000 ng/mL was strongly associated with the occurrence of solid cancer (107743). It is unclear if increased intake of vitamin B12, either through the diet or supplementation, directly affects the risk of cancer. It is possible that having cancer increases the risk of vitamin B12 elevation. However, one observational study has found that the highest quintile of dietary intake of vitamin B12 is associated with a 75% increased incidence of developing esophageal cancer when compared with the lowest quintile in never drinkers, but not drinkers (107147).
Renal ...There is a case report of oxalate nephropathy in a 54-year-old male which was determined to be related to the use of intravenous hydroxocobalamin as treatment for cyanide poisoning. Intermittent hemodialysis was started 5 days after admission, along with a low-oxalate diet, oral calcium acetate, and pyridoxine 5 mg/kg daily (107148). A review of the use of intravenous hydroxocobalamin for suspected cyanide poisoning in 21 intensive care units in France between 2011 and 2017 resulted in a 60% increased odds of acute kidney injury and a 77% increased odds of severe acute kidney injury in the first week. However, biopsies were not conducted and a direct link with use of hydroxocobalamin could not be made (107139).
Other ...Several studies have found that higher vitamin B12 levels may be associated with increased mortality or decreased survival rates in hospitalized elderly patients (82889,82812,82857,82895). Human research has also found a positive correlation between vitamin B12 status and all-cause mortality in Pima Indians with diabetes (82863).
General
...Orally or by injection, vitamin B6 is well tolerated in doses less than 100 mg daily.
Most Common Adverse Effects:
Orally or by injection: Abdominal pain, allergic reactions, headache, heartburn, loss of appetite, nausea, somnolence, vomiting.
Serious Adverse Effects (Rare):
Orally or by injection: Sensory neuropathy (high doses).
Dermatologic ...Orally, vitamin B6 (pyridoxine) has been linked to reports of skin and other allergic reactions and photosensitivity (8195,9479,90375). High-dose vitamin B6 (80 mg daily as pyridoxine) and vitamin B12 (20 mcg daily) have been associated with cases of rosacea fulminans characterized by intense erythema with nodules, papules, and pustules. Symptoms may persist for up to 4 months after the supplement is stopped, and may require treatment with systemic corticosteroids and topical therapy (10998).
Gastrointestinal ...Orally or by injection, vitamin B6 (pyridoxine) can cause nausea, vomiting, heartburn, abdominal pain, mild diarrhea, and loss of appetite (8195,9479,16306,83064,83103,107124,107127,107135). In a clinical trial, one patient experienced infectious gastroenteritis that was deemed possibly related to taking vitamin B6 (pyridoxine) orally up to 20 mg/kg daily (90796). One small case-control study has raised concern that long-term dietary vitamin B6 intake in amounts ranging from 3.56-6.59 mg daily can increase the risk of ulcerative colitis (3350).
Hematologic ...Orally or by injection, vitamin B6 (pyridoxine) can cause decreased serum folic acid concentrations (8195,9479). One case of persistent bleeding of unknown origin has been reported in a clinical trial for a patient who used vitamin B6 (pyridoxine) 100 mg twice daily on days 16 to 35 of the menstrual cycle (83103). It is unclear if this effect was due to vitamin B6 intake.
Musculoskeletal ...Orally or by injection, vitamin B6 (pyridoxine) can cause breast soreness or enlargement (8195).
Neurologic/CNS ...Orally or by injection, vitamin B6 (pyridoxine) can cause headache, paresthesia, and somnolence (8195,9479,16306). Vitamin B6 (pyridoxine) can also cause sensory neuropathy, which is related to daily dose and duration of intake. Doses exceeding 1000 mg daily or total doses of 1000 grams or more pose the most risk, although neuropathy can occur with lower daily or total doses as well (8195). The mechanism of the neurotoxicity is unknown, but is thought to occur when the liver's capacity to phosphorylate pyridoxine via the active coenzyme pyridoxal phosphate is exceeded (8204). Some researchers recommend taking vitamin B6 as pyridoxal phosphate to avoid pyridoxine neuropathy, but its safety is unknown (8204). Vitamin B6 (pyridoxine) neuropathy is characterized by numbness and impairment of the sense of position and vibration of the distal limbs, and a gradual progressive sensory ataxia (8196,10439). The syndrome is usually reversible with discontinuation of pyridoxine at the first appearance of neurologic symptoms. Residual symptoms have been reported in patients taking more than 2 grams daily for extended periods (8195,8196). Daily doses of 100 mg or less are unlikely to cause these problems (3094).
Oncologic ...In females, population research has found that a median intake of vitamin B6 1. 63 mg daily is associated with a 3.6-fold increased risk of rectal cancer when compared with a median intake of 1.05 mg daily (83024). A post-hoc subgroup analysis of results from clinical research in adults with a history of recent stroke or ischemic attack suggests that taking folic acid, vitamin B12, and vitamin B6 does not increase cancer risk overall, although it was associated with an increased risk of cancer in patients who also had diabetes (90378). Also, in patients with nasopharyngeal carcinoma, population research has found that consuming at least 8.6 mg daily of supplemental vitamin B6 during treatment was associated with a lower overall survival rate over 5 years, as well as a reduced progression-free survival, when compared with non-users and those with intakes of up to 8.6 mg daily (107134).
