Kolkata, Mar 9 : Sodium is an essential nutrient necessary for maintenance of plasma volume, acid–base balance, transmission of nerve impulses and normal cell function.
In healthy individuals, nearly 100 per cent of ingested sodium is absorbed during digestion, and urinary excretion is the primary mechanism for maintaining sodium balance. Even in hot, humid climates, there are only minimal loses through faeces and sweat. Acclimation to heat occurs rapidly; thus, within a few days of exposure to hot and humid conditions, individuals lose only small amounts of sodium through sweat.
Under conditions of extreme heat and intense physical activity that result in high sweat production, sodium losses in sweat are increased and appreciable; nonetheless, most individuals can replace the necessary sodium through food consumption, without dietary alterations, supplements or specially formulated products.
Sodium and chloride are the chemical components of common table salt; however, sodium can be found in other forms, and the primary contributors to dietary sodium consumption depend on the cultural context and dietary habits of a population.
Sodium is found naturally in a variety of foods, such as milk, meat and shellfish. It is often found in high amounts in processed foods such as breads, crackers, processed meats and snack foods. High amounts of sodium are also found in many condiments (e.g. soy and fish sauces). Thus, a diet high in processed foods and low in fresh fruits and vegetables is often high in sodium.
Although the minimum intake level necessary for proper bodily function is not well defined, it is estimated to be as little as 200–500 mg/day. Data from around the world suggest that the population average sodium consumption is well above the minimal physiological needs, and in many countries is above the value recommended by the Joint World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO) Expert Consultation of 2 g sodium/day (equivalent to 5 g salt/day).
Increased sodium consumption is associated with increased blood pressure, whereas lower sodium consumption appears to decrease blood pressure in adults . A number of recent high-quality systematic reviews of randomizedcontrolled trials (RCTs) have concluded that decreased sodium intake relative to usual or higher intake results in lowered blood pressure in adults with or without hypertension.UNI