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. 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.

Recommended Intake

Age GroupAdequate Intake
0-6 months5
7-12 months6
1-3 years8
4-8 years12
9-13 years20
14-18 years25
19+ years30

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 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.)
  • 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:

  • Nausea and vomiting
  • Hair loss
  • Fatigue
  • Depression
  • Hallucinations
  • Numbness of the extremities
  • Dry skin and seborrheic dermatitis
  • Red scaly rash in face
  • Biotin Toxicity

    There have been no reports of adverse effects due to eating too much biotin. Maximum dosages have not been established.

    Major Food Sources

    Biotin can be found in a wide variety of foods including eggs, liver, yeast breads, whole grains, sardines, legumes, and mushrooms.

    This table lists common foods and their biotin contents.

    FoodServing Size Biotin Content
    Egg, cooked1 large13-25
    Cheddar cheese1 ounce0.4-2
    Salmon3 ounces4-5
    Whole Wheat bread1 slice0.02-6
    Raspberries1 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 2 eggs, mushrooms, cheese, and assorted veggies. You can also add a hard boiled egg and some shredded 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.