The active ingredient of polysaccharide iron complex capsules is iron in the form of polysaccharide iron complex molecules. It is used clinically for the treatment of simple iron deficiency anemia, as well as maternal iron deficiency anemia, and it is administered to adults as 1-2 capsules orally once daily. Its adverse effects are sometimes gastrointestinal irritation or constipation. It is contraindicated in patients with hemochromatosis and iron-containing hemoglobin deposits. It has a high absorption rate because it is a complex preparation, which is present in the digestive tract as an intact molecule and can be absorbed in molecular form. It has a high absorption rate as confirmed by nucleotide labeling tests, and the absorption rate is not affected by the reduction of gastric acid, food composition, and has an extremely high bioavailability.