Biotin
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Biotin

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.

Functions

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.

Recommended Intake

Age GroupAdequate Intake
(micrograms/day)
0-6 months5
7-12 months6
1-3 years8
4-8 years12
9-13 years20
14-18 years25
19+ years30
Pregnancy30
Lactation35

Biotin Deficiency

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:

  • Infants with low biotinidase levels—Infants who are born with low levels of this enzyme may develop a deficiency. There is some debate among doctors about whether infants should be screened at birth for a deficiency of biotinidase.
  • People who require prolonged feeding through the vein—These patients usually did not receive biotin supplementation.
  • People who smoke— Smoking accelerates biotin metabolism, thus leading to a deficiency state.
  • People taking anticonvulsant drugs—These medications can inhibit the absorption of biotin or block the action of biotinidase.
  • People who eat a lot of raw eggs—A protein called avidin found in raw egg whites can bind biotin and inhibit its absorption. Cooked eggs do not present this problem. (Note: Eating raw eggs increases the risk of food-borne infection.)
  • People who are missing a portion of their small intestine function—This decreases the absorption of biotin.
  • People taking antibiotics long-term—Antibiotics kill both the good and bad bacteria; therefore, they may kill the bacteria that normally live in the intestine and produce biotin.
  • People who abuse alcohol—Since people who abuse alcohol tend to have poor diets, they are at risk for a deficiency of many nutrients, including biotin.
  • Pregnant women—There is some preliminary evidence that biotin deficiency can occur during a normal pregnancy, so women may consider taking a multi-vitamin that contains biotin.

Clinical symptoms of a biotin deficiency include:

  • Dry skin
  • Hair loss
  • Appetite loss
  • Fatigue
  • Depression
  • Heart abnormalities
  • Lethargy
  • Hallucinations
  • Neurologic disorders
  • Impaired growth
  • Numbness of the extremities
  • Red scaly rash in face and genital area

Biotin Toxicity

There have been no reports of adverse effects due to eating too much biotin.

Major Food Sources

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.

FoodServing Size Biotin Content
(micrograms)
Egg1 large13-25
Cheddar cheese1 ounce0.4-2
Salmon3 ounces4-5
Whole Wheat bread1 slice0.02-6
Rasberries1 cup0.2-2

Health Implications

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).

Tips for Increasing Your Biotin Intake

To increase your intake of biotin, try the following:

  • Have a bowl of shredded wheat, whole grain cereal, or oatmeal for breakfast.
  • Make an omelet with two eggs, mushrooms, cheese, and assorted veggies (peppers, cauliflower, broccoli). You can also add a hard boiled egg and some shredded American cheese to a leafy green salad.
  • Try this recipe for black bean and crab salad:
    • Mix together 1 pint frozen corn (thawed), 1 (8 oz) can of black beans (drained and rinsed), ¼ cup of red peppers (chopped), 1 (4 oz) can of green chilies (drained), ¼ cup minced cilantro, 4 green onions (chopped), and 12 ounces of chopped artificial crab meat.
    • For the dressing, add 1 teaspoon of cumin and ¼ teaspoon of black pepper, to 2 cloves of minced/chopped garlic. Mix into a paste and then add 2 teaspoons each of white wine vinegar, fresh lime juice, and water. Mix well and then whisk in 3 tablespoons of olive oil.
    • Pour dressing over the corn and bean mixture and stir well. Top with 2 thinly sliced jalapeno peppers. Makes 10 servings.

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 April 14, 2011.

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 2011 by Brian Randall, MD


Last updated Updated: 4/14/2011

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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