It is one of the important elements that constitute the human body, and its content in the human body ranks fifth after oxygen, hydrogen, carbon and nitrogen, accounting for about1.5% ~ 2% of the body weight. 99% of the total calcium in human body exists in bones. Because children are in the growing period, the daily calcium requirement is more than that of adults: 400 mg for infants under 6 doors and 600-800 mg for infants from 6 months to 10 years old. 13 ~16 years old is 1000 ~1200 mg, put OtO-11000 mg, and pregnant women and wet nurses are1500 ~ 2000 mg. Milk and dairy products in food are rich in calcium, and the absorption rate is also high. Vegetables and beans are also high in calcium, but the absorption rate of calcium is reduced due to the interference of oxalic acid and persimmon acid. Calcium content in common foods: per100g of food is as follows; 9 ~14 mg of rice, 29 mg of millet, 38 mg of flour, 367 mg of soybeans, 80 mg of mung beans, 277 mg of tofu, 0/00 mg of edamame/kloc, 68 mg of soybean sprouts, 4 1 mg of Chinese cabbage, 0/63 mg of Chinese cabbage, and oil. Kloc-0/9mg, Datoulai 357mg, Celery 300mg, Kelp 1 1 77mg, Citrus 56mg, Apple11mg, Strawberry 32mg, Banana 9mg, Human Milk 34mg, Milk/Kloc-0. Although the calcium content of human milk is low, hypocalcemia rarely occurs in human milk feeders because of the appropriate ratio of calcium and phosphorus and high absorption rate.