Man has been consuming sodium chloride (the chemical name for common salt) from as far back as history has been recorded. The body of a healthy person weighing about 65 kg contains 256 g of sodium chloride. Of this, just over half is found in the extra-cellular fluid. About 96 g is found in the bones and less than 32 g in the cells.
Sodium is a silver-white, highly reactive, alkaline, metallic element. It is soft and malleable. It is normally found inside the body and outside it in combination with other elements. It is essential for life and is present in the fluids of the body outside the cells.It is usually taken in the form of sodium chloride.
Sodium is almost completely absorbed from the gastro-intestinal tract in the normal individual, but substantial losses may occur due to vomiting and diarrhea. Most of the sodium consumed is excreted by the kidneys, with variable amounts being lost through the skin and stools. The sodium balance in the body is controlled by the hormone aldosterone, which is secreted by the adrenal gland. When the need for sodium increases, increased amounts of aldosterone are secreted which increase the re-absorption of sodium ions by the kidney tubules.
Skin losses may increase greatly when there is profuse perspiration due to strenuous physical exertion in a hot environment. Under such circumstances, salt depletion may be accompanied by heat exhaustion. Salt tablets may be taken with a liberal amount of water in this condition.
Functions of Sodium in the Body
- Sodium is the most abundant cation in the extracellular fluid of the body. It acts with other electrolytes, especially potassium, in the intracellular fluid, to regulate the osmotic pressure and maintain proper water balance within the body.
- It is a major factor in maintaining the acid-base equilibrium, in transmitting nerve impulses, and in relaxing muscles.
- It is also required for glucose absorption and for the transportation of other nutrients across cell membranes.
- Deficiency of sodium is caused by excessive sweating, prolonged use of diuretics, or chronic diarrhea. Severe deficiency of sodium requires administration of sodium chloride in the form of normal saline by an intravenous route.
- Sodium deficiency may lead to nausea, muscular weakness, heat exhaustion, and mental apathy. In case of mild deficiency of sodium chloride, taking a teaspoon of common salt in a pint of water or in any fruit juice, quickly restores health.
Vegetables like dry lotus stems and leafy vegetables are rich in sodium. Sodium is also present in a variety of pulses and legumes. Fruits, fish and meat also contain a substantial amount of sodium.
- Fresh fruits, eggplant, cabbage, cauliflower, tomatoes, potatoes, onions, peas, and pumpkin can be eaten.
- Oversupply of sodium is a more common problem because of overuse of dietary sodium chloride or common salt.
- Too much sodium may lead to water retention, high blood pressure, and even stomach ulcers.
- The adverse effects of excessive sodium chloride in the body can be rectified by avoiding the use of common salt. The point then is that getting used to a decreased amount of salt in the diet, is a matter of habit. What is salty to one person may be bland to another. Fortunately, getting used to less salt in the food does not take long.