This is present in the body as the chloride ion. It is present in extracellular fluid as sodium chloride. It is found within the cells as potassium chloride. Chloride ions are also known to be present in the red blood cells. It is an essential part of the gastric juice. Chlorides ions move freely across the cell maintain osmotic pressure and acid base balance. It is readily absorbed and excreted according to the body requirements.
It is important for the regulation of osmotic pressure. Chloride help to maintain the water balance and pH balances. They activate salivary amylase. Chloride provides the acid medium for the activation of the gastric enzymes and digestion in the stomach.
The requirement for chlorine has not been ascertained but if sodium chloride is taken liberally it ensures the adequate intake of chloride as well. Thus must of the chloride taken is from the common salt used during food processing and preparation.
Prolonged vomiting and diarrhea upsets and acid balance. Acidic chloride ions are replaced by bicarbonate ion resulting in alkalosis.
Common salt helps the body to normally meet the requirements of sodium and chlorine. Sodium ion are basic in reaction while the chloride ions are acidic and they are together responsible for the acid base equilibrium in the body. In very hot weather, excessive loss of salt from the body due to perspiration result in heat cramps. It is desirable to give sufficient salt during summer and when there is excessive vomiting and diarrhea. Heavy salt intake puts an extra load on the kidney for its exertion. About 5gms of salt added to the food daily improves its taste and is enough to meet the body requirements.