Methylcobamin is the more active form of B-12, therefore more easily utilized by the body, and more readily available for utilization. The common form, cyanocobalamin, is not. Sublingual, (under the tongue), or by injection seems to be the most effective route of administration. B-12 is needed to prevent anemia, as well as many other bodily functions, including, heart disease, proper digestion, and energy. I have written an article on the benefits of B-12, as well as the other B-complex vitamins.