Biotin is a member of the B-complex group of water-soluble vitamins. Water-soluble vitamins are stored in the body in very limited amounts and are excreted through the urine. Therefore, it is a good idea to have them in your daily diet. Biotin can be found in two natural forms—the free vitamin form and biocytin, which is composed of biotin attached to the amino acid lysine. Biocytin is an inactive form of the vitamin; the lysine must be removed before it can be used by the body.
Biotin is present naturally in a wide variety of foods. It is also made by the bacteria that normally live in our intestines.
Biotin's main function is to help your body's cells produce energy. It does this by working with four essential enzymes that break down fat, carbohydrate, and protein to yield energy. Biotin also plays a role in the synthesis and function of DNA.
Age Group | Adequate Intake (micrograms/day) |
---|---|
0-6 months | 5 |
7-12 months | 6 |
1-3 years | 8 |
4-8 years | 12 |
9-13 years | 20 |
14-18 years | 25 |
19+ years | 30 |
Pregnancy | 30 |
Lactation | 35 |
A biotin deficiency is rare in healthy people who eat a healthful diet, since we usually get enough from the bacteria living in our digestive tracts.
However, certain conditions and life stages can increase the risk of a deficiency. For example, an enzyme called biotinidase is essential to convert biocytin into biotin. Though both biocytin and biotin are easily absorbed in the small intestines, the body can only use the biotin form. If biotinidase is lacking or not working properly, a biotin deficiency can result.
Some people who may be at risk for a biotin deficiency include the following:
Clinical symptoms of a biotin deficiency include:
There have been no reports of adverse effects due to eating too much biotin.
Biotin can be found in a wide variety of foods including eggs, liver, yeast breads, whole grains, sardines, legumes, mushrooms, and cereals. Cauliflower, peanuts, and cheese can also be nutrient-dense sources of this vitamin. Fruits are generally not good sources.
This table lists common foods and their biotin contents.
Food | Serving Size |
Biotin Content
(micrograms) |
---|---|---|
Egg | 1 large | 10 |
Wheat germ | ¼ cup | 6 |
Oatmeal, cooked | ½ cup | 5 |
Shredded Wheat cereal | 1 ½ ounces | 4 |
Pancakes | 3- or 4-inch | 3 |
There is some highly preliminary evidence suggesting supplemental biotin can help to reduce blood sugar levels in people with diabetes. Biotin may also reduce the symptoms of diabetic neuropathy , though other supplements have much stronger evidence. Even weaker evidence suggests that biotin supplements can promote healthy nails and eliminate cradle cap (a scaly head rash often found in infants).
To increase your intake of biotin, try the following:
RESOURCES:
American Dietetic Association
http://www.eatright.org/
United States Department of Agriculture
http://www.usda.gov/wps/portal/usdahome/
CANADIAN RESOURCES:
Canadian Council on Food and Nutrition
http://www.ccfn.ca/
Dietitians of Canada
http://www.dietitians.ca/
References:
Biotin. Linus Pauling Institute. Oregon State University website. Available at: http://lpi.oregonstate.edu/infocenter/vitamins/biotin/ . Accessed May 4, 2009.
Mock DM. Biotin. In: Rucker B, Suttie J, McCormick D, MachlinL, eds. Handbook of Vitamins. New York, NY: Marcel Dekker; 2001:397-426.
Sealey WM, Teague AM, Stratton SL, et al. Smoking accelerates biotin catabolism in women. Am J Clin Nutr. 2004;4:932-935.
Last reviewed April 2009 by Maria Adams, MS, MPH, RD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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