Drinking milk can supplement calcium. Milk is a kind of food with high calcium content, the calcium content of milk is around 1mg/mL, so 1 box of 250ml milk contains about 250mg of calcium, and the calcium element needed by normal people is around 800mg/day. The calcium needs of children, pregnancy, lactation and menopause are around 1200mg/day. The results of the Chinese adult nutrition survey show that the calcium intake through three meals a day is less than 400mg, so it is difficult to provide a day’s calcium needs with only three meals a day. It is recommended that normal people can consume 250ml of pure milk, high-calcium milk or yogurt daily, but should avoid all kinds of milk-containing beverages, etc. Milk is recommended to drink before bedtime to effectively avoid mobilization of bone calcium into the blood at night to maintain blood calcium concentration, and special periods such as children, pregnancy, lactation and menopause require additional calcium intake.