SOURCE NATURALS - Vitamin B-125 - 180 TabletsDESCRIPTION B vitamins are essential components of numerous key enzyme systems, without which the body cannot function. Each B vitamin fills a different, complementary need, which is why they should usually be taken together. B vitamins act as coenzymes to catalyze numerous biochemical reactions, aid in energy production, blood cell formation, fat and protein amino acid metabolism, and are important for the normal functioning of the nervous system.