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):
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,2anemia, and nausea. Long-term use of anti-seizure
medications may also lead to biotin deficiency.3Alcoholics and people 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.89 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.
Are there any drug
interactions?
Certain medicines may interact with biotin. Refer to drug interactions for a list of those medicines.
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
1. Mock DM. Biotin. In: Shils ME, Olson JA, Shike M, Ross, AC (eds).
Modern Nutrition in Health and Disease. Baltimore: Williams and Wilkins, 1999,
459–66.
11. Somer E. The Essential Guide to Vitamins and Minerals. New
York: Harper, 1995, 70–2.
12. Zempleni J, Mock DM. Biotin biochemistry and human requirements.
J Nutr Biochem 1999;10:128–38 [review].
13. Debourdeau PM, Djezzar S, Estival JL, et al. Life-threatening
eosinophilic pleuropericardial effusion related to vitamins B5 and H. Ann
Pharmacother 2001;35:424–6.
The information presented in Aisle7 is for informational purposes only.
It is based on scientific studies (human, animal, or in vitro), clinical experience,
or traditional usage as cited in each article. The results reported may not necessarily occur
in all individuals. For many of the conditions discussed, treatment with prescription or over
the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist
for any health problem and before using any supplements or before making any changes in
prescribed medications. Information expires February 2010.
Reliable
and relatively consistent scientific data showing a substantial health benefit.
