Constitute human tissue. For example, the main components of bones and teeth are calcium and phosphorus, muscle contains sulfur, nerve tissue contains phosphorus and hemoglobin contains iron. In addition, inorganic salts are also components of some enzymes and hormones with important physiological functions, such as cytochrome, catalase and peroxidase, which all contain iron, while carbonic anhydrase and insulin contain zinc. Maintain the balance between water and electrolyte. Sodium and potassium are important cations for maintaining electrolyte and liquid balance in the body. Maintaining normal sodium content in the body plays a very important role in osmotic balance, acid-base balance and water-salt balance. Maintain osmotic pressure of tissues and cells. The distribution of potassium, sodium and other positive and negative ions in minerals is different inside and outside cells and in plasma. Together with protein and bicarbonate, they can maintain the osmotic pressure of various cells and tissues, make the tissues retain certain moisture and maintain the water balance of the body. Maintain the acid-base balance of the body. Cell activities need to be carried out in a near-neutral environment. Acidic ions such as sulfur and phosphorus are properly matched with basic ions such as calcium, magnesium, potassium and sodium, and the buffering effect of bicarbonate and protein can adjust and balance the pH in the body. Maintain neuromuscular excitability and cell membrane permeability. Magnesium, potassium, calcium and some trace elements play a very important role in maintaining normal heart function and cardiovascular health. Constitute bioactive substances in the body and participate in the activation of enzyme system. For example, iron is a component of hemoglobin, myoglobin and cytochrome systems. Participating in human metabolism, phosphorus is an indispensable substance for energy metabolism. Participate in the metabolism of protein, fat and sugar: Iodine is an important component of thyroxine, which can promote metabolism.