Vitamin B12 may be one of the most important of all the B vitamins, particularly because only true humanly usable B12 comes from animal sources. Yes, to all my vegetarian and particularly vegan friends, watch your B12 levels. There is no such thing as “vegan” or “vegetarian” B12 as far as your body goes. It needs along with it what is known as “intrinsic factor” which comes from animals. Fortunately B12 (as other B vitamins) will store in the body, but over time this may become a deficiency. In fact, a good friend of mine, after years of being a vegetarian has reintroduced more animal product into her diet after seeing a live blood analysis showing a lack of B12 and a move towards anemia.
So what does B12 do? It is a cofactor for two, yet very important enzymes. One is used for methionine metabolism. Methionine is an essential amino acid. The other enzyme aids in producing energy from proteins and fats. Overall B12 supports the nervous system, promotes the maturation of red blood cells (hence the tie to anemia when deficient in B12) and other cells, and supports bone and joint health.
B12 is available from animal products such as fish (halibut, salmon, scallops, shrimp, and snapper are best sources), lamb, beef, organ meats, and yogurt. It is important for the blood, digestive, hepatic, and nervous systems.