Biotin

Biotin, also known as vitamin H or coenzyme R, is a water-soluble B-vitamin (vitamin B₇).

It is composed of a ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. Biotin is a coenzyme for carboxylase enzymes, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis.

The only human health condition for which there is strong evidence of biotin's potential benefit as a treatment is biotin deficiency. Biotin deficiency can be caused by inadequate dietary intake or inheritance of one or more inborn genetic disorders that affect biotin metabolism. Biotin supplements are also used "off label" to accelerate hair and nail growth, and are included in some personal hygiene products due to these effects.

General overview

Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids. Biotin assists in various metabolic reactions involving the transfer of carbon dioxide. It may also be helpful in maintaining a steady blood sugar level. Biotin is often recommended as a dietary supplement for strengthening hair and nails, though scientific data supporting this outcome are weak. Nevertheless, biotin is found in many cosmetics and health products for the hair and skin.