Biotin is an essential coenzyme for a variety of carboxylation reactions, and is involved in the metabolism of fats, sugars and amino acids. Biotin is crucial for 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 acid synthesis into protein and the formation of DNA and RNA. As early as 1940, biotin was being researched for its effectiveness in promoting healthy hair and nails.