Biotin is an important vitamin that belongs to the B complex family (it is sometimes called vitamin B7). Biotin deficiency is rare in the United States, as the vitamin is usually produced in adequate amounts by intestinal bacteria, but it can occur in people with intestinal disorders and certain metabolic conditions.
Biotin plays a key role in cell growth, metabolism and several other body functions. Deficiency of biotin interferes with these processes, but is usually correctable with supplementation.
First signs of biotin deficiency include dry skin, brittle hair or hair loss, and a tendency to get skin infections and rashes. Without treatment, symptoms can progress to depression, muscle pains and movement disorder.
A blood test can reveal a person's blood biotin levels. There are also metabolites, such as 3-hydroxyisovaleric acid, that can give a doctor clues about whether a person's biotin status is sufficient.
Eating a healthy, balanced diet is usually sufficient to prevent biotin deficiency, as it is present in a wide variety of foods, including meats, eggs and many types of vegetables. In people with clinically proven biotin deficiency, taking a biotin supplement is the recommended treatment.
Eating large amounts of raw egg whites on a regular basis can induce biotin deficiency, since egg whites contain enzymes that interfere with the body's biotin absorption.