Sodium is commonly available from common salt or sodium chloride. About 50% of the total sodium present in the human body is found in the extracellular fluids- the fluids within the blood vessels. The remaining amount is distributed in the blood, blood plasma and intracellular fluids. Sodium can be easily interchanged between bones and the extracellular fluid. Some of it is also found in the deep regions of the long bones.
1. Sodium maintains normal osmotic pressure and water balance of the body as it is the principle electrolyte in extra cellular fluid.
2. Sodium accounts for 90% of the basic irons in the extracellular fluids and helps to maintain body neutrality by counter-acting the effect of the acid forming elements.
3. In the transmission of nerve impulses, sodium balance is absolutely necessary within the cell and outside the cell.
4. Sodium is also essential for the absorption of glucose and in the transport of other nutrients across membrances.
Common salt or sodium chloride is the chief source of sodium in the diet. It is primarily used as flavor to food during processing and preparation. It is present in food in widely varying amount, more generally being found in foods of animal origin than in those of plant origin.
It is found in milk, eggs, meat, fish poultry and in vegetables such as spinach, fenugreek, pulses and cereals.
Sodium Chloride requirements depend on climate, occupation and physical activity. On an average, 5-10 gms. of salt are sufficient for an adult. However, salt intake is restricted in the case of patients having high blood pressure, cardiac failure and nephritis.
Deficiency of salt in the diet may cause cramps of muscles, headache, tiredness or sickness.