biotin


Introduction
Biotin, a water-soluble B vitamin, acts as a coenzyme in the metabolism of protein, fats, and carbohydrates.
Where is it found?
Good dietary sources of biotin include
organ meats, oatmeal, egg yolk, soy, mushrooms, bananas, peanuts, and brewer’s yeast. Bacteria in the intestine also produce significant amounts of biotin, but evidence is conflicting as to whether biotin produced by intestinal bacteria is present at a location or is in a form that permits significant absorption by the body.1
Biotin has been used in connection with the following conditions (refer to the individual health concern for complete information):
Science Ratings - Health Concerns** - Brittle nails
** - Pregnancy
** - Type 1 diabetes
** - Type 2 diabetes
* - Seborrheic dermatitis (cradle cap)
*** - Reliable and relatively consistent scientific data showing a substantial health benefit.
** - Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
* - For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
Who is likely to be deficient?
Certain rare inborn diseases can leave people with depletion of biotin due to the inability to metabolize the vitamin normally. A dietary deficiency of biotin, however, is quite uncommon, even in those consuming a diet low in this B vitamin. Nonetheless, if someone eats large quantities of raw
egg whites, a biotin deficiency can develop, because a protein in the raw egg white inhibits the absorption of biotin. Cooked eggs do not present this problem. Long-term antibiotic use can interfere with biotin production in the intestine and increase the risk of deficiency symptoms, such as dermatitis, depression, hair loss,2 anemia, and nausea. Long-term use of anti-seizure medications may also lead to biotin deficiency.3 Alcoholics, people with inflammatory bowel disease, and those with diseases of the stomach have been reported to show evidence of poor biotin status. However, the usefulness of biotin supplementation for these people remains unclear.4 In animals, and possibly in humans, biotin deficiency can cause birth defects.5 As biotin deficiency may occur in as many as 50% of pregnant women,6 it seems reasonable to use a prenatal multiple vitamin and mineral formula that contains biotin.
How much is usually taken?
The ideal intake of biotin is unknown. However, the amount of biotin found in most diets, combined with intestinal production, appears to be adequate for preventing deficiency symptoms. Researchers have estimated that 30 mcg per day appears to be an adequate intake for adults.7 Typically, consumption from a Western diet has been estimated to be 30–70 mcg per day. Larger amounts of biotin (8–16 mg per day) may be supportive for people with
diabetes by lowering blood glucose levels and by preventing diabetic neuropathy.8 9 Biotin in the amount of 2.5 mg per day strengthened the fingernails of two-thirds of a group of people with brittle nails, according to one clinical trial.10
Are there any side effects or interactions?
Excess intake of biotin is excreted in the urine; no toxicity symptoms have been reported.
Biotin works with some other B vitamins, such as
folic acid, pantothenic acid (vitamin B5), and vitamin B12. However, no solid evidence indicates that people supplementing with biotin also need to take these other vitamins. Symptoms of pantothenic acid or zinc deficiency have been reported to be lessened with biotin,11 though people with these deficiencies should supplement with the nutrients in which they are deficient. Researchers have speculated that biotin and alpha lipoic acid may compete with each other for absorption or uptake into cells; but little is known about the importance of these interactions in humans.12
There is one report of a 76-year-old woman who developed a life-threatening condition (eosinophilic pleuropericardial effusion) while taking 10 mg of biotin per day and 300 mg of pantothenic acid per day.13 However, it is not clear whether the vitamins caused the problem.

Drug InteractionsCertain medicines interact with biotin: Some interactions may increase the need for biotin (+), other interactions may be negative (-) and indicate biotin should not be taken without first speaking with your physician or pharmacist, others may require further explanation (?). Refer to the individual drug article for specific details about an interaction.
Note: The following list only includes the generic or class name of a medicine. To find a specific brand name, use the
Medicines index.Anticonvulsants (+)Gabapentin (+)Glyburide (?)Insulin (+)Phenobarbital (+)Topical Corticosteroids (+)Valproic Acid (+)