b complex vitamins definition
vitamin B complex. n. 1. (Biochemistry) a large group of water-soluble vitamins occurring esp in liver and yeast: includes thiamine, riboflavin, nicotinic acid, pyridoxine, pantothenic acid, biotin, choline, folic acid, and cyanocobalamin.Sometimes shortened to: B complex.ny of a group of related vitamins important for normal cell growth and metabolism. The vitamins of the vitamin B complex include thiamine (vitamin B 1), riboflavin (vitamin B 2), pantothenic acid, niacin, biotin, and folic acid.