Baby three months to supplement calcium can not be generalized, need to be based on the child’s intake of milk and whether there is a deficiency of calcium and so on to see, usually enough milk or there is no deficiency of calcium and so on do not need to supplement calcium; on the contrary, need to supplement vitamin D and so on. 1. Milk intake: because the amount of calcium contained in breast milk and formula is able to meet the needs of normal growth and development of babies. Three months of the baby’s milk amount of 720 ~ 900mL, if the baby’s milk is sufficient, there is no need to supplement calcium. But if the child’s milk intake is insufficient, it may lead to calcium deficiency. 2. Calcium deficiency manifestations: when the baby has night terrors, sleep disturbance, excessive sweating, head shaking, pillow baldness, rickets and other manifestations, consider that the child may be caused by calcium deficiency. At this time, we should also pay attention to exclude whether the child is due to vitamin D deficiency caused by calcium deficiency. Vitamin D deficiency can lead to calcium and phosphorus absorption, utilization and ossification disorders, resulting in the appearance of calcium deficiency. Three-month-old babies if there is a calcium deficiency, you can follow the doctor’s advice to supplement vitamin D, if necessary, calcium supplements; if there is no calcium deficiency often do not need to supplement calcium, pay attention to the amount of milk and appropriate sun exposure can be. Suggest that parents and friends should take their children to the hospital regularly for health checks, if the baby has rickets and other manifestations, we should consult the doctor in time.