Biotin, also known as vitamin H or B7 and C10H16N2O3S (Biotin; Coenzyme R, Biopeiderm), is a water-soluble B-complex vitamin which is important in the catalysis of essential metabolic reactions to synthesize fatty acids, in gluconeogenesis, and to metabolize leucine. It is commonly found in pyruvate dehydrogenase as a carrier of HCO3-.