Iron supplementation needs to be continued for at least another 4 to 6 months after the normal level of hemoglobin in peripheral blood has been restored, and can be discontinued only after the ferritin is normal. After taking iron supplements orally, the peripheral blood reticulocytes increase first, and the hemoglobin concentration rises after two weeks, and the normal level can be restored in about 2 months. Iron supplements should be taken for 4-6 months after the hemoglobin is normal, and the medication can be stopped only after the ferritin is normal, which means that the regular treatment lasts about half a year. Iron is mainly used to correct iron deficiency anemia, commonly used oral iron supplementation drugs are ferrous sulfate, iron dextrose anhydride, polysaccharide iron complex, etc. Iron can be taken at the same time with vitamin C, which can promote iron absorption. If iron supplementation, hemoglobin rise immediately after the drug is given to stop, because at this time the body iron reserves are still insufficient, still in the state of iron deficiency, so there may be repeated anemia. Therefore, iron supplements should be taken according to a regimen under the guidance of a doctor in order to achieve the effect of correcting anemia.