The best time for infants to take calcium supplements is when infants may be at the stage of calcium deficiency or when they may be deficient in calcium due to faster growth. Infants growing faster within one year of age may have insufficient calcium supplementation, it is recommended to supplement calcium under the guidance of a doctor, babies can be supplemented with vitamin D after breakfast or appropriate sun exposure, synthesized or supplemented vitamin D can promote the absorption of calcium. Parents can also let the baby take calcium gluconate oral solution, lysine calcium phosphate granules and other calcium supplements under the guidance of the doctor. Appropriate calcium supplementation for babies can prevent rickets, promote bone growth, and prevent osteoporosis and developmental delay. In addition, parents need to be careful not to take calcium supplements for babies with milk, milk powder or supplements, which will not only affect the absorption of calcium, but also the absorption of protein.