Human Nutrition 3(3+0)

Lesson 39 : Sodium

Sodium chloride

All minerals except NaCl are usually present in sufficient amounts in a well balanced diet. Sodium chloride is the only mineral which is taken in more or less pure form in addition to the amount present in natural foods.

NaCl intake and excretion
A healthy adult excretes about 10 to 15 g. of NaCl daily in urine. Sodium chloride is also excreted in sweat and during excessive sweating in hot climates, and while doing hard work. The loss of NaCl in sweat may vary from 10 to 20 g. daily. During fasting or on salt free diets, the excretion of chlorides in urine may be decreased or only a trace of NaCl may be found. Absence of NaCl in urine is an indication for adding more NaCl to the diet. NaCl is stored in the subcutaneous tissue and during NaCl deprivation, the store is used up.

Requirement of Nacl depends on

1. Climate
2. Occupation
3. Salt content of diet

Table: Requirements of Nacl

Life stage/activity	g/day
Adults Moderate work Hard work Very hard work	10 15 20
Children	5 – 10
Adolescents Boys girls	10 – 20 10 – 20
Pregnant women	5 – 10
Lactating	15

Ref: Nutrition Expert group, ICMR(2010)

Sodium chloride content of animal foods is more than foods of vegetable origin.