Newborn babies in the morning when the AD supplement is the most appropriate. The main role of vitamin D is to promote the absorption of calcium in the body, but also to prevent the occurrence of rickets, the baby's main food is breast milk or formula, which contains vitamin AD, are unable to meet the needs of the baby's growth, which may cause related diseases, so you can properly supplement the vitamin AD drops, it is recommended that you eat until the baby is 1 to 2 years old. It is generally recommended that full-term newborns begin oral vitamin AD supplementation of vitamin A and vitamin D3 about 10 to 14 days after birth. vitamin A and carotene are both very difficult to pass through the placenta into the fetus, so the newborn's serum and liver levels of vitamin A are significantly lower than the mother's, such as in the postnatal period can not get adequate vitamin A supplementation, easy to vitamin A deficiency. Newborn growth and development is rapid, vitamin D needs to increase.

Newborns tend to have insufficient sunlight, and if the mother's vitamin D nutrition is insufficient in the second trimester of pregnancy, the newborn's body has fewer reserves of vitamin D, and it's more important to insist on vitamin D. That is, from 3 to 4 weeks after birth, you should take concentrated cod liver oil, start with one drop per day and gradually increase it to a maximum of 5 drops, and take it when you sleep at night for a better effect. It is recommended to take one month and stop taking it for a period of time. Usually eat more green leafy vegetables and fruits, which are rich in nutritive value, and then take your baby to sunbathe more. Newborns in the birth of 15 days to two years of age, all need routine supplementation of vitamin D3, 400IU / d within one week of age, 1-2 years of age 600IU / d, continuous supplementation to two years of age.

Unless the child's skin is fully exposed to sunlight for more than half an hour or more a day in the summer, additional vitamin D3 supplementation is not necessary. Vitamin AD, on the other hand, is a combination of vitamin A and vitamin D3, so it can also be taken until two years of age. The reason why children need to supplement vitamin D3 is because vitamin D3 is a fat-soluble vitamin is less abundant in breast milk, and children usually have a short period of time for their skin to receive sunlight, and their growth and development is rapid, so they need to be supplemented routinely every day. Vitamin D3 is a key vitamin to promote calcium absorption, calcium is a large number of elements of the human body, in the food source is relatively rich, the reason why the lack of calcium is due to the lack of vitamin D3 and make the calcium malabsorption.