The B complex vitamins are very important in the world of sport, due to their participation in the metabolism. The B complex is made up of 8 water-soluble vitamins: thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin (vitamin B7), folic acid (vitamin B9), cobalamin (vitamin B12).