Together\'s vegan, wholefood vitamin B12 is made from organic Shiitake mushrooms and contains three natural, active and preferred forms of B12. The three forms of B12; Methylcobalamin, Adenosylcobalaminare & hydroxylcobalamin each have a specific beneficial role to play in the body. Methylcobalamin and Adenosylcobalamin are highly bioavailable co-enzyme forms that do not require conversion by the body and each has a different role to play. Methylcobalamin is active in the cell plasma, nerves & brain. Adenosylcobalamin is active in the Mitochondria (our energy production workers). Hydroxocobalamin is not itself a coenzyme form of B12, yet can easily be converted by the body into both methyl- and adenosylcobalamin. Hydroxcobalamin has the added benefit of circulating for longer in the body making the perfect partner form for an all round synergistic approach. Instead of taking a single active ingredient, a combination of all of the natural B12 forms is the optimal solution for supplementing B12 as it mirrors the B12 content in foods.