Anemic people can not eat vitamin b12 should be based on the cause of anemia to decide, there are many causes of anemia, such as iron deficiency anemia, aplastic anemia, megaloblastic anemia, etc., of which megaloblastic anemia is mostly caused by the lack of folic acid and vitamin B12, vitamin B12 should be supplemented. 1. Iron deficiency anemia: mostly due to insufficient iron intake (such as dietary deficiencies, etc.) or excessive iron loss (such as gastrointestinal bleeding, peptic ulcer, etc.) resulting in anemia, mostly small cell hypochromic anemia, in addition to active treatment of the primary pathology, the main symptomatic supportive treatment of supplemental iron supplements such as ferrous succinate. There is no need to take vitamin B12. 2. Aplastic anemia: caused by bone marrow hematopoietic failure, supportive therapy is mainly blood transfusion, the use of hemostatic drugs such as phenol sulfonyl ethylamine, anti-fibrinolytic drugs such as aminocaproic acid and hematopoietic stem cell transplantation. This kind of anemia can not eat vitamin B12. 3. Megaloblastic anemia: mostly caused by folic acid and (or) vitamin B12 deficiency or absorption disorders, in the elimination of the cause at the same time, should be supplemented with folic acid and vitamin B12, it should be noted that some patients may be combined with iron deficiency, should also be supplemented with iron. Anemia may also have other causes such as hemolytic anemia, it is recommended to improve the timely examination, to clarify the cause of the disease, standardized treatment. Vitamin B12 has an allergic reaction, avoid self-medication.