Dietary reference values for potassium

Abstract

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for potassium. The Panel decides to set DRVs on the basis of the relationships between potassium intake and blood pressure and stroke. The Panel considers that randomised controlled trials and an observational cohort study carried out in a European adult population provide evidence that a potassium intake of 3,500 mg (90 mmol)/day has beneficial effects on blood pressure in adults. Furthermore, there is consistent evidence from observational cohort studies that potassium intakes below 3,500 mg/day are associated with a higher risk of stroke. Available data cannot be used to determine the average requirement of potassium but can be used as a basis for deriving an adequate intake (AI). A potassium intake of 3,500 mg/day is considered adequate for the adult population and an AI of 3,500 mg/day for adult men and women is proposed. For infants and children, the AIs are extrapolated from the AI for adults by isometric scaling and including a growth factor. An AI of 750 mg (19 mmol)/day is set for infants aged 7-11 months. For children, AIs from 800 mg (20 mmol)/day (1-3 years old) to 3,500 mg/day (15-17 years old) are set. Considering that the daily accretion rate of potassium in fetal and maternal tissues can be met by the adaptive changes which maintain potassium homeostasis during pregnancy, the AI set for adults applies to pregnant women. For lactating women, the amount of potassium needed to compensate for the losses of potassium through breast milk is estimated and an AI of 4,000 mg (102 mmol)/day is proposed.

Revised Reference Values for Potassium Intake

“…EFSA also investigated the association between potassium intake and risk of kidney stones [17]. Several cohort studies indicate an association between low potassium intake and increased risk of kidney stones [59,60,61].…”

“…EFSA has recently highlighted that there is a lack of evidence regarding the association between potassium intake and risk of fracture and concludes that data regarding the association between intake of potassium supplements and bone density is inconsistent and thus, the evidence is insufficient [17]. …”

“…Thus, in order to assess the potassium intake of the general population, 24-h potassium excretion is often estimated based on spot urinary potassium concentrations. However, due to the possible over- or underestimation of potassium excretion, spot urine samples provide relatively inaccurate estimates of potassium intake in individuals [15,16,17]. …”

“…In addition, the urinary potassium excretion has to be corrected by the absorption and the excretion rate of potassium. For this, a conversion factor of 1.3 was chosen based on 2 studies [13,20] and by following the approach of the World Health Organization (WHO) [21] and the European Food Safety Authority (EFSA) [17]. This results in an estimated median potassium intake of approximately 3,900 mg/day for women (5th [P5] to 95th percentiles [P95]: 1,800-8,000 mg/day) and approximately 4,300 mg/day for men (P5-P95: 2,000-8,000 mg/day).…”

Outcome of a public consultation on the Draft Scientific Opinion of the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) on Dietary Reference Values for potassium

“…The AI of 3,500 mg (90 mmol) of potassium/day was based on evidence from RCTs for a bloodpressure lowering effect of dietary potassium in adults at doses between 3,500 and 4,700 mg (90-120 mmol)/day (Aburto et al, 2013), on evidence for a lower risk of hypertension associated with intakes of 3,500 mg potassium/day from one prospective cohort study carried out in a European adult population of normotensive people which used multiple 24-hour urine collections to calculate potassium intakes (Kieneker et al, 2014), and on evidence from a dose-response meta-analysis of prospective cohort studies (n=8) for a lower risk of stroke associated with potassium intakes up to 3,500 mg/day; above this value, the inverse relationship was weakened and more uncertain (Larsson et al, 2011). A systematic review and dose-response meta-analysis including all the prospective cohort studies considered by Larsson et al (2011) plus those which had been published thereafter, and which were described individually in the draft opinion released for public consultation, has become available during the consultation period (Vinceti et al, 2016). In this analysis including 16 studies, an inverse relationship between potassium intake and risk of stroke was observed up to around 3,500 mg/day, where the RR was 0.78 (95% CI = 0.70-0.86).…”