Natural Factors B12 Methylcobalamin - A biologically active form of B12 in quick-dissolve sublingual form for easy absorption and longer circulation. Clinical human studies show that supplementation of sublingual B12 can reduce homocysteine levels, reducing the risk factor for heart disease and stroke, as well as arthritis, diabetes and renal failure. Taking Methyl B12 has many other benefits, including restoration of normal sleep patterns and improved moods. B12 deficiency is fairly common, especially in the elderly and vegetarians. The methylcobalamin (Methyl B12) form of B12 is easy to assimilate as it is already in its most usable form.