A molecular model of cyanocobalamin, a chemical compound most commonly converted into a usable form of vitamin B12 in animals. Vitamin B12 is involved in the production of proteins, blood cells, and myelin sheaths in nerves, as well as the metabolic breakdown of carbohydrates, lipids, and proteins. Atoms are colored dark gray (carbon), light gray (hydrogen), red (oxygen), blue (nitrogen), and pink (cobalt).