Vitamin B12, also referred to as cobalamin, is a water-soluble vitamin. It contributes to the successful synthesis of DNA, the normal functioning of the nervous system, and the production of hemoglobin. Vitamin B-12 deficiency is common among both vegans and meat eaters alike, and more people today are reaching for supplementation. It contributes to the successful synthesis of DNA, the normal functioning of the nervous system, and the production of hemoglobin.