Vitamins, Minerals and Dietary Supplements
What is biotin?
Biotin is a water-soluble vitamin that belongs to the group of B vitamins. It is
obtained not only by eating certain foods but is also produced by bacteria in the intestines.
Since biotin is not stored in body fat, after the body uses what it needs, any excess is excreted
in the urine.
Why do we need it?
Biotin plays a number of roles in the human body. Like the other B vitamins, it is essential
for the metabolism of proteins and carbohydrates into energy. It is involved in
the production of amino acid proteins and fatty acids, aids in the synthesis of
hormones and cholesterol, and contributes to the growth of healthy skin and hair
How much biotin should I take?
Although no recommended daily allowances (RDA) have been established for biotin; however,
most health experts generally agree on the following amounts:
- Adult men: between 30-100 milligrams/day
- Adult women: between 30-100 milligrams/day
- Children aged 7-10: 30 milligrams/day
- Infants: 15 milligrams/day
- Pregnant/lactating women: between 30-100 milligrams/day.
What are some good sources of biotin?
In addition to being produced naturally by the body, biotin can be found in a number of food sources. Among
the best sources are eggs, milk, mushrooms, bananas, tomatoes, whole-grain cereals,
nuts, yeast, broccoli, potatoes (white and sweet) and lean beef.
What can happen if I don't get enough biotin?
Biotin deficiency is almost
unheard of; however, deficiencies can be caused by surgical removal of the stomach,
or by being on an inadequate or unusual diet. Raw egg whites, for instance, bind
biotin and make it unavailable for absorption. Alcohol and tobacco also decrease
Biotin deficiency may lead to dermatitis, brittle nails
and hair loss. Severe deficiency can lead to high blood cholesterol levels and
What can happen if I take too much?
There is no evidence of toxicity with biotin. Because it is water-soluble and
is not stored in the body, the chances of enough biotin building up to toxic levels
are highly unlikely. Most people taking multivitamins with high levels of biotin
or eating foods rich in amounts of biotin need not worry about toxicity.
- Drug information for biotin. Available from
- Vitamins, carotenoids and phytochemicals. Available from WebMD.
Feinstein A. Prevention's Healing with Vitamins. Emmaus, PA: Rodale Press, Inc., 1996.
- Kennedy R. Biotin. Doctor's Medical Library January 15, 1999.
- Zempleni J, Mock DM. Biotin biochemistry and human requirements.
J Nutr Biochem 1999;10:128–38.
- Hochman LG, Scher RK, Meyerson MS. Brittle nails: responses to daily biotin
supplementation. Cutis 1993;51(4):303–5.