Children should not add extra salty salt until after the age of one week, because the kidney function is not perfect within one week, especially the dilution and concentration function of the kidney is not mature, if you add salt to children too early, it will cause the kidney load to increase and cause kidney damage. Within one week of age, children can get enough salt through milk powder or supplemental food. The main component of salt is sodium chloride, and infant formula and supplemental food contain sodium and chloride ions. Therefore, even if children within one week of age do not add additional salty salt, they will meet their normal physiological needs and will not need to be given salty salt until after one year of age.