Why is iron supplementation necessary for dialysis anemia? Long-term hemodialysis patients have many reasons for anemia, and iron deficiency is one of the most important reasons because iron is an important raw material for hematopoiesis, and long-term hemodialysis patients can lose 10-33 mg of iron per week, and often more than 1 g of iron per year. Iron can be lost through the dialysis membrane during the dialysis process, and long-term malnutrition, insufficient intake of iron-containing substances and liver retention of iron in uremic patients can all cause iron deficiency. Iron deficiency can be caused by long-term malnutrition, insufficient intake of iron-containing substances and iron retention in the liver. In addition, when erythropoietin is applied to treat nephrogenic anemia, erythropoiesis increases and the demand for iron increases, resulting in functional or absolute iron deficiency. Therefore, for dialysis anemia, supplementation with erythropoietin along with iron supplements is necessary to effectively improve anemia.