Vitamin B12 deficiency is mainly caused by the body’s possible inadequate intake of vitamin B12 or due to poor absorption. Clinically, patients are often characterized by megaloblastic anemia, neurological disorders, lingual inflammation and widespread symmetrical skin pigmentation. In terms of treatment, it is recommended to eat a diet rich in vitamin B12, such as the intake of animal protein, such as eggs, fish, shrimp, crab meat, etc.. Vitamin B12 deficiency can also be improved by taking vitamin B12 tablets orally, such as taking 2 capsules 3 times a day for 2 weeks, which can be taken together with folic acid to assist in the absorption of vitamin B12. For severe deficiency, vitamin B12 can be supplemented by injection, usually once a day, or once every other day for 3 weeks.