Comments and suggestions: it is recommended to actively check and determine the specific situation. Vitamin d or calcium can be supplemented first when necessary. Oral cod liver oil, the preventive dose is 500 ~ 1000 units, about 3 ~ 5 drops per day, and the therapeutic dose is 1000 ~ 5000 units per day. If it is concentrated cod liver oil, take 1 ~ 2 drops; Followed by calcium supplement, baby calcium tablets, high quality and low price is the first choice, if economic conditions permit, you can take eel calcium, calcium-covered oral liquid, giant calcium and so on.