Background: Potassium (K) is an essential mineral and major intracellular electrolyte involved in the regulation of blood pressure, muscle contraction and nerve transmission in humans. Major dietary sources of K include fruits and vegetables, starchy roots and tubers, and whole grains. The aim of this study was to assess and report: (i) the sufficiency of K in national food systems globally, (ii) to quantify the contribution from food groups, and (iii) to explore spatial and temporal trends in the period of 1961-2017.
Methods: Food supply and demography (1961-2017), K composition and K requirement data were combined to estimate per capita human dietary supplies of potassium (DSK), adequate intake of K (AIK) and K sufficiency ratio (KSR) at national, regional, continental and global levels.
Results and discussion: Globally, the mean ± SD. DSK (mg capita-1 d-1) increased from 2984 ± 915 in 1961 to 3796 ± 1161 in 2017. There was a wide range in DSK between geographical regions and across years, with particularly large increases in east Asia, where DSK increased from <3000 to >5000 mg capita-1 day-1. Roots and tubers contributed the largest dietary source of K, providing up to 80% of DSK in most regions. At the global level, throughout the 57-year period, the population-weighted KSR was <1 based on the 2006 Institute of Medicine AIK recommendation, while it was >1 based on the 2019 National Academies of Science and the 2016 European Union AIK recommendation. While KSR ≥ 1 shows sufficiency of DSK, KSR < 1 does not indicate K deficiency risk.
Conclusion: Due to the absence of a Recommended Daily Allowance (RDA) for K, this study used the ratio of DSK:AIK (i.e., KSR) to assess dietary K sufficiency. Estimates of dietary K sufficiency are, therefore, highly sensitive to the AIK reference value used and this varied greatly based on different institutions and years. To quantify the risk of dietary K deficiency, bridging the data gap to establish an RDA for K should be a global research priority.
Keywords: adequate intake; potassium sufficiency ratio; potassium to sodium ratio; recommended daily allowance.