The commonly referred to salt is sodium chloride, a white crystalline compound composed of a sodium ion and a chlorine ion. Sodium, along with other inorganic salts (i.e., minerals) such as potassium, calcium, magnesium, chloride, bicarbonate, and phosphate, are essential for human health. So, why do people need to consume salt?
Each kilogram of human body contains approximately 40 millimoles of sodium ions, of which about 50% are distributed outside the cells, about 10% exist within the cells, and approximately 40% are contained in bone matrix. Sodium salts play a crucial role in regulating the body's water balance. The kidneys reabsorb sodium to conserve water, maintaining the body's sodium homeostasis and ensuring normal fluid and circulating blood volume. Sodium ions also participate in the excretion of acidic metabolites, helping to maintain the body's acid-base balance. The chloride ions in table salt are an important component of gastric acid. Additionally, sodium and chloride ions are involved in the bioelectrical activities of nerve, muscle, and certain glandular cells.
If people do not consume enough salt over a long period of time, they may experience low sodium levels in the body, leading to symptoms such as loss of appetite, weakness in the limbs, dizziness, and, in severe cases, anorexia, nausea, vomiting, accelerated heart rate, weak pulse, muscle cramps, blurred vision, and weakened reflexes. However, consuming too much salt can also harm health, such as causing hypertension. Therefore, the World Health Organization recommends that adults consume no more than 5 grams of salt per day.