Safe Dosages of Biotin

Discovered in 1924, biotin is a member of the B vitamin family. Minute amounts of biotin, also known as vitamin B-7, are present in a wide variety of foods. Much of the biotin in the food chain is produced by fungi and bacteria. To date, there are no known toxic side effects associated with taking biotin supplements, even in dosages several times greater than established adequate intake levels.

Functions

Biotin is a required cofactor for five critical enzymes in the human body. Without biotin, these enzymes cannot function. The biotin-dependent enzymes are a specific type known as carboxylases, which refers to their chemical function. Carboxylases add tiny chemical groups to larger molecules, which changes their structure and function. The biotin-dependent enzymes aid in the formation and metabolism of certain fats, and the production of glucose from nonsugar precursors. Biotin also interacts with the genetic material inside your cells, influencing which genes are active.

Adequate Intake

Nutritionist Paul Insel, Ph.D. and colleagues note in their book "Discovering Nutrition" that there is insufficient information available to determine a recommended daily allowance for biotin. Therefore, the Institute of Medicine has established adequate intake levels, or AIs, which are amounts believed to be sufficient to support good health. The AI for biotin for adults age 19 and older is 30 mcg daily. For infants and toddlers through age 3, the daily AI for biotin is 5 to 8 mcg. Among children ages 4 through 18, the daily biotin AI ranges from 12 to 25 mcg.

Deficiency

Biotin deficiency is rare in the United States. Possible signs and symptoms include thinning hair, loss of hair color, scaly facial and genital rashes, numbness and tingling in the arms and legs, depression, hallucinations and a profound lack of energy. People with a rare genetic disorder that prevents absorption of dietary biotin also experience frequent infections due to poor immune system function.

Uses of Supplements

Treatment of a biotin deficiency is the only indication for taking supplements for which there is conclusive proof of benefit. The National Institutes of Health reports that there are insufficient data to determine whether biotin supplements may help lower blood sugar levels in diabetics; relieve the pain of diabetic nerve damage; improve finger- and toenail strength; or slow hair loss.

Warning

Although there are no known side effects associated with taking large doses of biotin, the possibility of toxicity cannot be ruled out. Talk with your doctor before taking biotin supplements to be sure they are safe for you. In general, the safest dosage for any medication or supplement is the lowest dose that produces the desired effect.