Children 9–13 years: 20 mcg
Children 14–18 years: 25 mcg
Adults age 19 and older: 30 mcg
Pregnant women: 30 mcg
Breastfeeding women: 35 mcg
Sources of biotin
Biotin is found in small quantities in many foods.
Bacteria in the large intestine also make biotin. Unlike
some vitamins, biotin is recycled and reused by the
body. Daily intake does not need to be high because
only small amounts are lost in urine. Biotin is stable
and little is lost when foods are exposed to heat, light,
or air.
Theapproximatebiotincontent in commonfoodsis:Bread, whole wheat, 1 slice: 6 mcg
Egg, 1 cooked: 25 mcg
Liver, cooked, 3 ounces: 27 mcg
Chicken, cooked, 3 ounces: 3 mcg
Pork, cooked, 3 ounces: 2 mcg
Salmon, cooked, 3 ounces: 4 mcg
Swiss chard, cooked, 1/2 cup: 5.2 mcg
Cauliflower, raw, 1/2 cup: 2 mcg
Biotin deficiency
Biotin deficiency is very rare worldwide. Only a
few conditions are known to cause biotin deficiency.
Two rare inherited genetic disorders cause the body to
need excessive amounts of biotin. These disorders are
treated with high-dose biotin supplements. Prolonged
(months or years) consumption of raw egg whitescan
also cause a deficiency. A protein in raw egg whites
binds biotin and makes it unavailable to the body.
Cooking the egg releases the biotin. Receiving all nutri-
tion through intravenous feeding (total parenteral
nutrition or TPN) for an extended period may also
lead to a shortage of biotin in the body.
Symptoms of biotin deficiency include skin and
hair problems, such as a red scaly rash on the face,
increased susceptibility to fungal infections, brittle
hair, and hair loss. Individuals may also develop seiz-
ures, problems with coordination, and muscle cramps.
Biotin deficiency has not been known to cause death.
These symptoms have many other causes that should
be considered first because biotin deficiency is so rare.
Precautions
In many species, pregnant animals who are biotin
deficient give birth to offspring with birth defects at a
higher rate than animals who have adequate levels of
biotin. The same effect has not been seen in humans.
However, blood levels of biotin tend to drop in preg-
nant women, causing concern among researchers that
pregnant women may develop marginal biotin defi-
ciency with no visible symptoms.Dietary supplements
of biotin are not routinely recommended for women
who are pregnant, but these women should make a
special effort to get an adequate intake of 30 mcg
biotin daily through diet. Pregnant and breastfeeding
women should not take a biotin dietary supplement
unless directed by their healthcare provider.Interactions
Biotin is known to interact with a few drugs and
dietary supplements.
Antibiotics taken over a long period may reduce the
amount of bacteria in the large intestine that synthe-
size biotin.
Long-term use of drugs used to prevent seizures such
as phenytoin (Dilantin), primidone (Mysoline), car-
bamazepine (Tegretol), phenobarbitol (Solfoton)
and possibly valproic acid cause a reduction in the
blood level of biotin.
High doses of pantothenic acid may decrease the
amount of biotin absorbed from the large intestine.Complications
No complications are expected from biotin. Even
when large doses are taken for long periods, there are
no reported side effects.Parental concerns
Biotin deficiency is rare and biotin excess is so
benign that parents should have almost no concern
about their children’s biotin needs being met by diet.Resources
BOOKS
Berkson, Burt, and Arthur J. Berkson.Basic Health Publi-
cations User’s Guide to the B-complex Vitamins. Laguna
Beach, CA: Basic Health Publications, 2006.
Gaby, Alan R., ed.A-Z Guide to Drug-Herb-Vitamin Inter-
actions Revised and Expanded 2nd Edition: Improve
Your Health and Avoid Side Effects When Using Com-
mon Medications and Natural Supplements Together.
New York: Three Rivers Press, 2006.
Lieberman, Shari, and Nancy Bruning.The Real Vitamin
and Mineral Book: The Definitive Guide to Designing
Your Personal Supplement Program. 4th ed. New York:
Avery, 2007.
Pressman, Alan H., and Sheila Buff.The Complete Idiot’s
Guide to Vitamins and Minerals, 3rd ed. Indianapolis,
IN: Alpha Books, 2007.Biotin