Biotin

General information

Biotin is a water-soluble vitamin of the B complex (vitamin B ₁₀ , also called vitamin H), and is found in many foods, especially eggs and liver. Biotin is involved in the action of four carboxylases:

• acetyl-CoA carboxylase, which catalyses the binding of bicarbonate to acetyl-CoA to form malonyl-CoA in the synthesis of fatty acids;

• pyruvate carboxylase, which is involved in gluconeogenesis;

• methylcrotonyl-CoA carboxylase, which catalyses an essential step in the metabolism of leucine;

• propionyl-CoA carboxylase, which catalyses essential steps in the metabolism of amino acids, cholesterol, and fatty acids.

Although biotin has been proposed as a treatment for diabetes mellitus, brittle nails, and hair loss, there is little good evidence of its efficacy in these conditions. It has also been used as a skin-conditioning agent in many cosmetic products in concentrations of 0.0001–0.6% [ ].