Page 253

TABLE 11-1 Estimated Sodium, Chloride, and Potassium Minimum Requirements of Healthy Personsa

Age

Weight
(kg)a

Sodium
(mg)a,b

Chloride
(mg)a,b

Potassium
(mg)c

Months

       

0-5

4.5

120

180

500

6-11

8.9

200

300

700

Years

       

1

11.0

225

350

1,000

2-5

16.0

300

500

1,400

6-9

25.0

400

600

1,600

10-18

50.0

500

750

2,000

> 18d

70.0

500

750

2,000

a No allowance has been included for large, prolonged losses from the skin through sweat.

bThere is no evidence that higher intakes confer any health benefit.

cDesirable intakes of potassium may considerably exceed these values (-3,500 mg for adults—see text).

d No allowance included for growth. Values for those below 18 years assume a growth rate at the 50th percentile reported by the National Center for Health Statistics (Hamill et al., 1979) and averaged for males and females. See text for information on pregnancy and lactation.

1984). Thus, a minimum average requirement for adults can be estimated under conditions of maximal adaptation and without active sweating as no more than 5 mEq/day, which corresponds to 115 mg of sodium or approximately 300 mg of sodium chloride per day. In consideration of the wide variation of patterns of physical activity and climatic exposure, a safe minimum intake might be set at 500 mg/day. Such an intake is substantially exceeded by usual diets in the United States, even in the absence of added sodium chloride. Although no optimal range of salt intake has been established, there is no known advantage in consuming large amounts of sodium, and clear disadvantages for those susceptible to hypertension. From this and other considerations, a Food and Nutrition Board committee recently recommended that daily intakes of sodium chloride be limited to 6 g (2.4 g of sodium) or less (NRC, 1989).

Pregnancy and Lactation 

During pregnancy, there is an increased need for sodium because of the increased extracellular fluid volume in the mother, the requirements of the fetus, and the level of sodium in the amniotic fluid. This need is normally met in part by physiological responses of the renin-angiotensin-aldosterone systems (Pike and Smiciklas, 1972). Given a pregnancy weight gain of 11 kg (70% of which is extracellular water containing 150 mEq of sodium per



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement