Vitamin B7. Molecular model of biotin (C10.H16.N2.O3.S), also known as vitamin B7, vitamin H and coenzyme R. This vitamin is required for cell growth, the production of fatty acids, and the metabolism of fats and amino acids. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and sulphur (yellow).