Malnutritional anemia is not always iron deficiency anemia; it can also be megaloblastic anemia or mixed anemia. Malnutritional anemia is simply a variety of anemia caused by insufficient intake, excessive loss or poor utilization of hematopoietic raw materials. Hematopoietic raw materials refer to the hematopoietic cell proliferation, differentiation, metabolism of the necessary substances, such as proteins, lipids, vitamin B12, folic acid, iron, etc., any one of the hematopoietic raw material insufficiency or utilization of the obstacle may lead to a reduction in the production of red blood cells. Anemia caused by reduced iron intake or excessive loss is iron deficiency anemia. If the anemia is caused by folic acid or vitamin 12 deficiency, it is megaloblastic anemia. Deficiencies of multiple hematopoietic materials can cause mixed anemia. Clinically, for patients with anemia, it is feasible to measure iron, folic acid and vitamin B12 to differentiate the specific causes of anemia, and to use targeted medication for the lack of specific hematopoietic raw materials. Therefore, patients with anemia should not blindly treat themselves, and it is recommended to consult regular hospitals and receive standardized treatment under the guidance of physicians.