Calcium, iron and zinc are best taken as separate supplements, not as a trio. Calcium, iron and zinc are all very important mineral elements for the human body. Among them, calcium can be involved in bone growth; iron is high in hemoglobin, and iron deficiency can trigger iron deficiency anemia; zinc is extremely important for maintaining human intelligence, immunity, and physical development, as well as participating in the repair of the skin mucous membrane barrier. Calcium, iron and zinc, if supplemented at the same time, will compete with each other, thus reducing the absorption rate of each other. In order to avoid this, it is best to space out the three for a certain period of time, so as to ensure the full absorption of each. In addition, iron supplementation needs to be accompanied by vitamin C to promote iron absorption. Improper supplementation of calcium, iron and zinc is likely to irritate the gastrointestinal tract, causing constipation, vomiting and other side effects. In addition, patients suffering from hypercalcemia, hypercalciuria and renal rickets are prohibited from blindly supplementing calcium; patients with iron overload, hemochromatosis or ferritin-containing hemosiderosis, and thalassemia are prohibited from iron supplementation; and patients with acute or active ulcerative disease are prohibited from supplementing zinc. In summary, calcium, iron, zinc and other drugs need to be used under the guidance of a doctor.