| Noun | 1. | B-complex vitamin - originally thought to be a single vitamin but now separated into several B vitaminscholine - a B-complex vitamin that is a constituent of lecithin; essential in the metabolism of fat inositol - an optically inactive alcohol that is a component of the vitamin B complex pantothen, pantothenic acid - a vitamin of the vitamin B complex that performs an important role in the oxidation of fats and carbohydrates and certain amino acids; occurs in many foods niacin, nicotinic acid - a B vitamin essential for the normal function of the nervous system and the gastrointestinal tract | |