There is a wide range of calcium preparations available on the market, pediatricians and parents often feel at a loss when selecting such drugs for their children, experts say that in clinical practice, the following four elements are used to make a comprehensive judgment. First, the source of calcium: calcium supplementation to be safe, the first should choose a good source of calcium. There are three main raw materials for calcium supplements on the market: calcium carbonate processed and purified from ore, calcium extracted from animal bones, and calcium extracted from marine organisms. Animals or marine life may cause the accumulation of harmful substances (such as lead, mercury and other heavy metals) in the body because of the pollution of the surrounding environment. Therefore, to give children a calcium supplement, choose refined calcium carbonate processed and purified by ore, more safe and reliable. Second, the amount of calcium content: pay attention to the content of calcium elements in various commercially available calcium preparations. The calcium content of various common calcium preparations is generally in the range of 10% to 40%, which varies a lot, so when buying calcium products, you should pay attention to the calcium content calculated in terms of calcium elements as indicated on the product packaging. Three, containing vitamin D: calcium absorption needs vitamin D assistance. Children’s gastrointestinal tract function is weak, poor absorption, usually supplemental calcium absorption rate of 20%-40%. Calcium preparations rich in vitamin D can effectively supplement calcium. Fourth, taste: calcium preparations of calcium content is high, absorption is good, if the child does not love to eat, but also can not achieve the effect of calcium supplementation. Therefore, when purchasing calcium preparations for children, attention should also be paid to choosing calcium preparations with good taste and suitable for children’s habits, so that children can easily take calcium and maximize the compliance of children taking medication, thus achieving the effect of calcium supplementation.