Calcium supplementation for children is best in spring and summer. Because the temperature increases in spring and summer, outdoor activities increase, babies increase the time of sunlight exposure, after sunlight exposure to the skin, can promote the absorption of calcium, so in these two seasons, the best absorption of calcium supplements. To ensure outdoor activities in about two hours a day, and at the same time, pay attention to the reasonable addition of supplementary food or more calcium-containing food, such as shrimp, bone broth, meat, etc.. To carry out physical exercise, such as climbing and jumping, which can promote bone development.