For full-term infants, the intake of vitamin AD is 400 IU per day starting two weeks after birth and continuing until one week of age, then changing to 700 IU per day until two weeks of age. For premature infants, the daily intake of vitamin D supplementation is 800 IU two weeks after birth, which is changed to 400 IU per day for 2-3 months until one week of age, and is also increased after two years of age. Vitamin A can promote the development of the eye, which is beneficial to the development of the eye, and can strengthen the immunity of the respiratory tract. Vitamin D can promote the absorption of calcium in the intestine and the deposition of calcium in the bones, which can prevent pediatric rickets. When the weather is good in summer, try to take your baby outdoors and get more sunlight. The 7-dehydrocholesterol stored under the baby’s skin can be converted into vitamin D after ultraviolet light exposure and stored in the body’s liver for backup, so more sunlight is good for the body.