Source Naturals B-50 promotes and supports natural, healthy energy production throughout your body. B-vitamins are essential components of numerous key enzyme systems, 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.