First, let children do more outdoor activities, receive enough sunlight, and promote the transformation of calcium into vitamin D. Second, pay attention to diet and give children more foods with high calcium content, such as milk, egg yolk, animal liver, fish and shrimp, nuts, and high-quality bean products. Avoid eating some puffed food, such as potato chips and popcorn. Third, appropriate oral calcium supplements, such as calcium gluconate oral liquid.