Dietary Supplement Biologically Active Form of B12 Support for Nerve Function, Energy Production & Red Blood Cells Purity & Potency Guaranteed Natural Factors Methylcobalamin is active immediately upon absorption, while other forms (e.g., cyanocobalamin) must be converted to methylcobalamin in a two-step process. Methylcobalamin demonstrates exceptional activity in areas where other forms are simply not active. B12 supplementation is recommended for vegetarians and those suffering from B12 deficiency. All Natural Factors products are manufactured in accordance with the Government of Canada's Good Manufacturing Practices (GMP), among the highest standards in the world.