Vitamin B₁₂ Tablets are used for the treatment of megaloblastic anemia, and Vitamin B₁₂ Injections are mainly used for megaloblastic anemia due to endogenous factor deficiencies, and are also used as an adjunctive treatment for subacute co-transformation neurological lesions, such as neuritis. Vitamin B₁₂ is generally available in two dosage forms: vitamin B₁₂ tablets and vitamin B₁₂ injection. Vitamin B₁₂ tablets are generally commonly used in clinics for megaloblastic anemia, but may cause adverse reactions such as hypokalemia and hyperuricemia in patients, and its contraindications are not yet clear. Vitamin B₁₂ injection is mainly used for megaloblastic anemia caused by internal factor deficiency, but also for subacute combined degenerative neurological lesions, such as neuritis and other diseases. It may cause allergic reactions such as rash, pruritus, diarrhea and allergic asthma after intramuscular injection, and the contraindications are currently unspecified. Vitamin B₁₂ should be used to check blood potassium after 48 hours of treatment for anemia in order to detect any hypokalemia. When used for neurological damage, it should be used after the diagnosis has not been clarified, so as not to mask the clinical manifestations. The use of medication needs to be under the guidance of a doctor, do not use it blindly on your own.