ample, in the DASH-sodium trial, sodium intakes were adjusted by energy level. At the lowest level of sodium intake, individuals consuming 1,600 kcal received 0.90 g (40 mmol)/day of sodium; at 2,100 kcal, 1.15 g (50 mmol)/day of sodium; at 2,600 kcal, 1.38 g (60 mmol)/day; at 3,100 kcal, 1.60 g (70 mmol)/day of sodium; and at 3,600 kcal/day, 1.8 g (80 mmol)/day of sodium (Svetkey et al., 1999).

The median range of estimated energy intakes for men and women 19 to 50 years of age in the latest Continuing Survey of Food Intake by Individuals (CSFII) (1994–1996, 1998) was ≈ 2,476 to 2,718 kcal/day and 1,659 to 1,757 kcal/day, respectively (IOM, 2002/2005), or an average overall median energy intake of 2,150 kcal/day. An active lifestyle has been recommended that requires approximately 3,100 and 2,400 kcal/day for young men and women, respectively (IOM, 2002/2005). Those individuals who are more physically active and therefore require more energy than median intakes observed in the CSFII data (IOM, 2002/2005) will likely consume sodium in excess of the AI. In contrast, those individuals who consume a lower intake of energy (e.g., 1,600 kcal/day) and who are physically inactive would likely have an adequate sodium intake with intakes below the AI. Of course, with restricted energy intake, careful dietary planning would be needed to meet recommended intakes for other nutrients.

Sodium chloride needs may be affected in a number of clinical conditions. For example, use of diuretics has been reported to lead to hyponatremia, although this appears to be a consequence of impaired water excretion rather than of excessive sodium loss since it can be corrected by water restriction. Other clinical states that can lead to increased renal salt losses include adrenal cortical insufficiency, intrinsic renal disorders (e.g., oliguric renal failure, medullary cystic disease, nephrocalcinosis), and certain diseases (e.g., cystic fibrosis, diabetes). In these situations, sodium should not be unduly restricted, and medical advice appropriate for the individual should be obtained.

Dietary Reference Intakes (DRIs) may be used to assess nutrient intakes as well as for planning nutrient intakes. Box 8-1 summarizes the appropriate uses of the DRIs for individuals and groups.