Newborns can take vitamin D drops, in the “Chinese children’s vitamin A, vitamin D clinical application of expert consensus” pointed out that newborns should be born as early as possible after the birth of vitamin D supplementation, the daily supplementation of the dose of 400-800U, in order to prevent vitamin D deficiency and insufficiency, to ensure that infants and young children’s growth and development needs. For preterm infants, low birth weight infants, and multifetal infants, vitamin D supplementation should be started one week after birth at 800 U per day, and then changed to 400 U per day after three months.For children with recurrent respiratory tract infections, diarrhea, iron-deficiency anemia, and malnutrition, it is recommended that vitamin D supplementation be given at 400-800 U per day, as vitamin D needs are high and consumed more.