Sodium and potassium intakes among US adults: NHANES 2003-2008

Abstract

Background: The American Heart Association (AHA), Institute of Medicine (IOM), and US Departments of Health and Human Services and Agriculture (USDA) Dietary Guidelines for Americans all recommend that Americans limit sodium intake and choose foods that contain potassium to decrease the risk of hypertension and other adverse health outcomes.

Objective: We estimated the distributions of usual daily sodium and potassium intakes by sociodemographic and health characteristics relative to current recommendations.

Design: We used 24-h dietary recalls and other data from 12,581 adults aged ≥20 y who participated in NHANES in 2003-2008. Estimates of sodium and potassium intakes were adjusted for within-individual day-to-day variation by using measurement error models. SEs and 95% CIs were assessed by using jackknife replicate weights.

Results: Overall, 99.4% (95% CI: 99.3%, 99.5%) of US adults consumed more sodium daily than recommended by the AHA (<1500 mg), and 90.7% (89.6%, 91.8%) consumed more than the IOM Tolerable Upper Intake Level (2300 mg). In US adults who are recommended by the Dietary Guidelines to further reduce sodium intake to 1500 mg/d (ie, African Americans aged ≥51 y or persons with hypertension, diabetes, or chronic kidney disease), 98.8% (98.4%, 99.2%) overall consumed >1500 mg/d, and 60.4% consumed >3000 mg/d-more than double the recommendation. Overall, <2% of US adults and ~5% of US men consumed ≥4700 mg K/d (ie, met recommendations for potassium).

Conclusion: Regardless of recommendations or sociodemographic or health characteristics, the vast majority of US adults consume too much sodium and too little potassium.

FIGURE 1.

Estimated usual intake of sodium (in mg/d) among US adults aged ≥20 y by sex, NHANES 2003–2008, n = 12,581. R statistical software was used to plot the estimated probability function (in mg Na) of usual intakes from the 1000 representative intakes. The figure represents the probability of an individual's usual sodium intake falling within a particular region given by the integral of individual usual sodium intake density over the region. The integral over the entire space is equal to one.

FIGURE 2.

Estimated usual intake of sodium (mg/d) among US adults aged ≥20 y by hypertension status, NHANES 2003–2008, n = 12,581. R statistical software was used to plot the estimated probability function (in mg Na) of usual intakes from the 1000 representative intakes. The figure represents the probability of an individual's usual sodium intake falling within a particular region given by the integral of individual usual sodium intake density over the region. The integral over the entire space is equal to one.

FIGURE 3.

Estimated usual intake of sodium (mg/d) among US adults aged ≥20 y by recommended sodium intake according to the 2010 Dietary Guidelines for Americans, NHANES 2003–2008, n = 5535. Fasting subsample. According to the Dietary Guidelines for Americans 2010, all Americans should reduce daily sodium intake to <2300 mg (8). Population subgroups who would benefit from further reductions in sodium intake to 1500 mg/d include “persons aged 51 years and older and those of any age who are African-American or have hypertension, diabetes, or chronic kidney disease” (8). Vertical lines are drawn at 1500 and 2300 mg Na/d. R statistical software was used to plot the estimated probability function (in mg Na) of usual intakes from the 1000 representative intakes. The figure represents the probability of an individual's usual sodium intake falling within a particular region given by the integral of individual usual sodium intake density over the region. The integral over the entire space is equal to one.