Reducing the sodium-potassium ratio in the US diet: a challenge for public health.

BACKGROUND The 2010 Dietary Guidelines emphasized that dietary sodium should be limited to 2300 mg/d, with a lower limit of 1500 mg/d for adults aged >50 y, non-Hispanic blacks, and those with diabetes, hypertension, or chronic kidney disease. The potassium goal remained at 4700 mg/d. OBJECTIVE The objective was to identify subpopulations for whom the 1500- or 2300-mg Na/d goals applied and to examine the joint sodium and potassium intakes for these persons. DESIGN The analyses were based on NHANES 2003-2008 data for 12,038 adult men and women aged ≥20 y. Persons aged >50 y, non-Hispanic blacks, and persons with hypertension, diabetes, and chronic kidney disease were identified. Mean sodium, potassium, and energy intakes were obtained from 2 nonconsecutive 24-h dietary recalls. Historical analyses of the sodium-potassium ratios in the American diet were based on NHANES 1971-2006. RESULTS Among persons recommended to consume <2300 mg Na/d, <0.12% jointly met the sodium and potassium guidelines. In the 1500-mg/d group, the guidelines were jointly met by <0.015%. Based on Dietary Guidelines, the corresponding dietary sodium-potassium ratio was either 0.49 (2300/4700) or 0.32 (1500/4700). Historical analyses of NHANES data by age-sex groups from 1971 to 2006 showed that sodium-potassium ratios were never <0.83. CONCLUSIONS Joint dietary guidelines for sodium and potassium, intended for most American adults, are currently being met by ≤0.015% of the population. Extraordinary efforts will be needed to meet the recommendations of the Dietary Guidelines.