Sodium is the principal cation of the extracellular compartment. About 50 mmol/kg body weight of sodium is present in human body, of which about 50% is present in bones, 40% in extracellular fluids and the remaining 10% in soft tissues.
Sodium is present mostly maintains the osmotic pressure and maintains the osmotic pressure of the extracellular fluid.
In addition, it activates some enzymes, such as amylase. Sodium absorption is rapids; it starts 3 – 6 min after intake and is completed within 3 h. Daily intake of sodium averages 2.5 g (females) to 3.3 g (males); the adult’s minimum requirement ranges form 1.3 – 1.6 g/day (equal to 3.3 – 4.0 g/day NaCl).
The intake of too little or too much sodium can result in serious disorders. From a nutritional standpoint, the daily sodium intake should be limited o 2.3 g (equivalent to 6 g NaCl).
A low intake of sodium can be achieved by a nonsalty diet or by using diet salt. Biochemical functions of sodium including:
*Neuromuscular excitability
*Fluid balance
*Acid-base balance
*Membrane transport
Major element: Sodium
