Sakura (pseudonym), 1 year old, does not imitate and does not point to objects for consultation. According to the mother’s description, the baby did not learn any action or language when taught at home and did not feel close to her. In the process of contact with the baby, it was found that the baby did interact better with the father, and it was also found that the mother was too anxious about the baby’s behavior, which was probably the main reason why the baby was not close to the mother. Parents often leave messages in the background asking questions about vitamin D supplementation, so I’ve summarized the issues that are more frequently consulted, so parents should collect them! Is vitamin D calcium? Vitamin D is not calcium, but it can promote the absorption of calcium, is a good partner of calcium. If the vitamin D supplement is not enough, it will affect the absorption of calcium, which is an important substance to promote bone development and blood clotting, once lacking, the baby is easy to suffer from rickets. Fish oil and vitamin AD supplements, which one is better to take? Fish oil comes from the flesh of deep-sea fish and contains mainly DHA and EPA, but almost no vitamin D. For babies who need vitamin D supplements, the effect is very little. Vitamin AD supplements, commonly known as “cod liver oil”, are mostly synthetic compound preparations with a ratio of 3:1 of vitamin A to D, which is the best absorption ratio for babies. Therefore, for babies who need to supplement vitamin D, vitamin AD can be supplemented, but fish oil is not recommended. When to start taking it? How to take it? For normal full-term babies, vitamin D supplementation should be started two weeks after birth, 400 IU/day. According to China’s “Recommendations for the Prevention and Treatment of Vitamin D Deficiency Rickets”, premature or low weight babies should take vitamin D supplementation immediately after birth, 800IU~1000IU/day for the first 3 months, and 400~500IU/day after 3 months until 2 years old. How old can I take it? The recommendation in the United States is to supplement from birth until adolescence. Canada and the UK recommend a lifetime of supplementation (because of the short daylight hours). Our recommendation is 400 IU/day of vitamin D for infants and toddlers up to 2 years of age (for premature or low birth weight infants, follow the above method). What about after the age of 2? If you live in the north and don’t see the sun all year round or don’t get much sun, you can take a lifetime supplement. If you live in the south and get a lot of sunshine, you can skip the supplementation. Can vitamin AD be toxic? The dose of vitamin AD poisoning given in the Chinese Dietary Reference Intake and Pediatrics: A single intake of more than 300,000 IU of vitamin A may cause acute toxicity; a daily intake of about 50-100,000 IU taken continuously for more than 6 months may cause chronic toxicity. Toxicity can occur with 20-50,000 IU of vitamin D taken daily for several weeks or months. In the case of Iconocin, for example, it is equivalent to eating hundreds of Iconocin at once or taking dozens of capsules every day for six months before chronic poisoning can occur, which is obviously impossible as long as you feed normally. Do I need to take extra vitamin D supplements if I have it in my formula? In addition to vitamin D preparations, formula milk also contains a certain amount of vitamin D. Formula-fed babies need to be supplemented according to the amount of vitamin D contained in formula milk. The daily requirement for a normal full-term baby is 400 IU, and the amount of vitamin D in formula milk is measured in “μg”, 400 IU = 10 μg. If you are not sure, it is best to seek professional medical guidance. Why do preterm babies need to take double the dose of vitamin D in the first 3 months after birth? Normal babies need a lot of calcium to increase their length by 25 cm from birth to one year old, and preterm babies grow faster and need more. The absorption and utilization of calcium mainly depends on vitamin D. Both fat-soluble vitamins and water-soluble vitamins in breast milk are difficult to meet the needs of preterm babies to catch up with their growth, especially vitamin A and vitamin D. Therefore, babies need extra vitamin D supplementation, and preterm babies should double the dose of supplementation.