B-complex vitamins are needed by the body for energy production, synthesis of blood cells, healthy nervous system function, and countless other metabolic processes.* The forms of the B vitamins found in foods and most supplements, however, require conversion into their active forms before they can perform their functions as co-factors in biochemical reactions.* NOW Co-Enzyme B-Complex contains B vitamins in their active or "co-enzyme" forms. Natural color variation may occur in this product.