Methylcobalamin is used in treating diseases of vitamin B12 deficiency (such as pernicious anemia), or diseases of effective B12 deficiency, such as vitamin B12 metabolic pathway. Methylcobalamin is retained in the body better than cyanocobalamin. Methylcobalamin normalizes protein transport in nerve cells in people with diabetes. It exhibits inhibitory effects on nerve degeneration in neuropathies induced by drugs. Methylcobalamin accelerates the metabolic pathways of nucleic acids, proteins and lipids through its involvement in the transmethylation reaction; thus, it exerts a repairing effect on injured nerve tissues. Clinically, Methylcobalamin is effective and useful for the treatment of numbness, pain and paralysis due to peripheral neuropathies.