The B groups of vitamins are as follows Thiamin (B1);Riboflavin (B2);Niacin (B3); Pantothenic acid (B5); Pyridoxine (B6);Biotin (B7);Folate or 'folic acid' when included in supplements (B9);Cyanocobalamin (B12).Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism.Chemical and physical properties of Vitamin B12: Vitamin B12 has the largest and most complex chemical structure of all the vitamins. It is unique among vitamins in that it contains a metal ion, cobalt.Vitamin B12 is a unique water-soluble vitamin that requires a specific protein called intrinsic factor for absorption in the body.The chemical name of vitamin B12 is that it's cyanocobalamine