Calcium supplementation should be analyzed according to the baby’s specific situation. Preterm babies can take calcium supplementation 1 week after birth, regular formula-fed full-term babies should take calcium supplementation 2 weeks after birth, and breastfed full-term babies usually start to take calcium supplementation after 6 months. Preterm babies are generally weak and likely to be deficient in calcium, so calcium supplements should be given as early as possible, usually 1 week after birth. Ordinary formula-fed children are also prone to calcium deficiency, so it is best to start calcium supplementation 2 weeks after birth. Breast milk has high nutritional value, and breastfed full-term babies usually do not have calcium deficiency, so calcium supplementation usually starts after 6 months. Calcium deficiency can lead to rickets, chicken breast, affect brain development and other conditions in babies, so parents should pay attention to observe whether their children have symptoms of calcium deficiency, if there is any abnormality, they should go to the hospital for checkups and take calcium supplements under the guidance of doctors.