Biotin is an essential coenzyme for a variety of carboxylation reactions, and is involved in the metabolism of fats, sugar and amino acids. Specifically, the utilization of glucose for energy, the breakdown and utilization of fatty acids in energy production, and the removal of the amine group in amino acid metabolism, thereby assisting amino acids in being synthesized into protein as well as the formation of DNA and RNA. As early as 1940, biotin was being researched for its effectiveness in promoting healthy hair and nails.