The best time of day to take vitamin D for babies is between meals, either after breakfast and before lunch, or after lunch and before dinner, depending on your situation. After birth, babies should start taking vitamin D under the guidance of a doctor, usually within half an hour to two hours after a meal, when the bioavailability of vitamin D is at its highest and best, which is conducive to the absorption of vitamin D and avoids stimulating the mucous membrane of the gastrointestinal tract. In addition, in the summer or outdoor activities, the sunlight is sufficient to directly through the skin directly into vitamin D, should be appropriate to reduce or stop taking vitamin D. In winter or sunlight is not sufficient, should be timely supplementation of vitamin D. In daily life, parents should pay attention to the timely and reasonable addition of complementary food to the baby, can effectively prevent the occurrence of rickets baby.