A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Vitamin B-12 (cobalamin) plays an essential role in red blood cell formation, cell metabolism, nerve function and the production of DNA, the molecules inside cells that carry genetic information. B12 plays a critical role in maintaining healthy reproduction by improving the function of reproductive organs, reducing OS, pro-inflammatory cytokines, and circulating homocysteine levels.