Vitamin B12 and methylcobalamin are generally not recommended to be taken together, you can choose any one of these drugs according to medical advice. Vitamin B12 is generally used in the treatment of megaloblastic anemia, contraindications to the use of the drug is not known, should be used with caution in the family hereditary retrobulbar optic neuritis, smoking amblyopia, gout. Adverse reactions include hypokalemia and hyperuricemia. Methylcobalamin, an endogenous coenzyme B12 and a member of the vitamin B12 family of drugs, is used clinically for the treatment of peripheral neuropathy. It should be contraindicated in people who are allergic to methylcobalamin and should not be used in large quantities for prolonged periods of time by those working with mercury and mercury compounds. Adverse reactions include poor appetite, nausea, vomiting, diarrhea, and skin rash. Vitamin B12 and methylcobalamin belong to the same family, the simultaneous use of drugs to a certain extent is a duplication of drugs, so it is not recommended to use together. The use of specific drugs should be carried out under the guidance of a specialist, not unauthorized use of drugs.