Methylcobalamin is a type of Vitamin B12. Vitamin B12 comes in several kinds including hydroxy-, cyano-, and adenosyl-, but only the methyl form is used in the central nervous system. Methylcobalamin is water-soluble and easy to give as a pill. It is used in treating diabetic neuropathy. As shown in the references below, it does not have the same effect as a regular (cyano-) B-12 supplement.