1. Milk that is about to expire can be directly made into cheese, and the calcium to phosphorus ratio of cheese is very appropriate, which is beneficial to the absorption of calcium.

The types are complex, with at least more than 100 kinds. The main ingredients include water, fat, phospholipids, protein, lactose, inorganic salts, etc.

2. The inorganic salts in milk are also called minerals.

Milk contains cations such as Ca?, Mg?, K?, Fe? and anions such as PO, SO, Cl?; in addition, there are trace elements I, Cu, Zn, Mn, etc.

Calcium in nature exists in a chemical state. Only when it is absorbed passively or by plants to form biologically active calcium can it be better absorbed and utilized by the human body.

Milk is rich in active calcium and is one of the best sources of calcium for humans. One liter of fresh milk contains about 1,250 mg of active calcium, ranking first among many foods. It is about 101 times that of rice, 75 times that of lean beef, and 75 times that of lean beef.

110 times that of pork, not only is it high in content, but the lactose in it can promote the absorption of calcium by the human intestinal wall, with an absorption rate as high as 98%, thereby regulating calcium metabolism in the body, maintaining serum calcium concentration, and promoting bone calcification.

Good absorption is especially critical for calcium supplements.

Therefore, the statement "milk can supplement calcium" has its scientific reason.