Vitamin D3 drops are mainly used for vitamin D supplementation, because after vitamin D deficiency, children’s intestinal calcium absorption capacity is significantly reduced, which will cause children to develop hypocalcemia. After the occurrence of hypocalcemia, it will cause children to sweat more, chicken chest, rib beads, and even X-leg and O-leg. Therefore, it is necessary to give children vitamin D3 drops from 2 weeks after birth. After long-term vitamin D3 supplementation, children’s vitamin D levels will be very adequate and intestinal calcium absorption will be more pronounced, and after intestinal calcium absorption increases, vitamin D and blood calcium levels will mostly be in the normal range, which is very beneficial to children’s health.