Food supplement is the best choice.
Let children eat more calcium-rich foods, such as oysters, herring, shrimp skin, seaweed, fish powder, sesame seeds, peanuts, pig liver and so on. These foods are not only rich in calcium, but also easily absorbed by the human body.
Liquid medicine supplement
If the child is too young, you can choose liquid medicine to supplement it. The liquid medicine is not only easy to be absorbed, but also easy to control the dosage.
Get more sunshine.
More sun exposure contributes to the absorption of calcium. Every morning or evening, letting children bask in the sun can increase the synthesis of vitamin D and promote the absorption of calcium.