Inorganic salts are more useful and diverse, such as calcium, iron, potassium and sodium. Based on the above examples of inorganic salts, their roles include maintaining water-electrolyte balance, promoting development, and maintaining musculoskeletal excitability. 1. Calcium: The role of calcium ions may include maintaining the excitability of muscle nerves, regulating cellular and capillary permeability, promoting the activity of various enzymes in the body, maintaining the acid-base balance in the body, and participating in the process of blood coagulation. 2. Iron: Iron ions have many functions in the human body. Iron is the basic material for the generation of hemoglobin, which can avoid diseases caused by insufficient hemoglobin production. Iron ions can also improve the body’s immunity and reduce the incidence of infectious diseases. 3. Potassium: Potassium ions can regulate the acid-base balance of body fluids as well as maintain the osmotic pressure inside the cells, and also participate in the metabolism of sugar and protein. Potassium can help the body maintain nerve health and keep the heart in a stable beating rhythm. 4. Sodium: The main role of sodium in the body is to maintain the water balance in the body, but also tears, bile and other components of the fluid. At the same time, sodium ions are also involved in a variety of roles such as muscle movement, cardiovascular contraction, maintenance of blood pressure and energy metabolism. There are more types of inorganic salts and they have more physiological roles, which need to be elaborated according to the different types.