Vitamin B12 is not used to treat skin conditions. Vitamin B12 is a water-soluble vitamin, and the main role of the drug is to treat megaloblastic anemia caused by endogenous factor deficiency, and it can also be used as an adjunctive treatment for neuritis. Vitamin B12 is used as an eye drop to relieve visual fatigue, improve dry eye symptoms and improve eye regulation. However, the scope of its indications does not include skin diseases. Skin disease is a more general term, which covers a wide range, including allergic skin diseases, autoimmune skin diseases, inflammatory skin diseases, etc. The treatment needs to be based on the cause of the disease to take different treatments, such as anti-allergy and anti-itch, immunomodulators, and anti-inflammatory drug therapy. Different diseases need to choose different drugs, and the choice of drug treatment must strictly follow the doctor’s instructions.