For more information about the health effects, please refer to the background paper by Ulla Toft, Nanna Louise Riis and Antti Jula (Toft et al., 2023).
Dietary sources and intake. Potassium is widely available in different types of foods and about 90% of the ingested potassium is absorbed. The most important dietary sources are potatoes, fruits, vegetables, cereal and cereal products, milk and dairy products, and meat and meat products. The average potassium intake ranges from 2400 to 4200 mg/d (Lemming & Pitsi, 2022).
Main functions. Potassium is essential for normal cell and membrane function, for maintenance of fluid balance, acid-base balance, and for normal excitation in nerves and muscles. Results from observational studies have shown that a potassium intake above 3500 mg/day is associated with a reduced risk of stroke. Intervention studies provide evidence that potassium intakes at this level have a beneficial effect on blood pressure, particularly in individuals with high blood pressure or high sodium intakes (>4000 mg/day) (Toft et al., 2023). Increased potassium intake from dietary supplements reduces blood pressure in adults with prehypertension or hypertension, but not in adults with normal blood pressure (NASEM, 2019). Elevated blood pressure is very common in the adult population in Nordic and Baltic countries and a leading risk factor for premature death and disability (Clarsen, in press).
Interaction with other nutrients. The metabolism of potassium is strongly related to that of sodium due to the Na+/K+-ATPase pump that maintains the extracellular/intracellular concentration. Potassium is also interrelated with calcium and with magnesium.
Indicator for recommended intake. The plasma concentration of potassium is strictly regulated within narrow limits by homeostasis and can thus not be used to assess status. No sensitive or specific biomarker to determine potassium status is currently proposed (NASEM, 2019).
Main data gaps. The lack of biomarkers for potassium status and the uncertainties of the data relating potassium intake to chronic outcomes are the main data gaps. The estimation of potassium requirements during lactation is uncertain.
Deficiency and risk groups. Potassium deficiency due to low dietary intake is rare. High intakes are regulated via renal excretion or cellular uptake and release. There is no evidence of adverse effects of high dietary potassium intake in healthy individuals. People with kidney dysfunction may have a risk of hyperkalemia, which may be lethal if untreated.
Dietary reference values. The links between potassium intakes and chronic disease were recently evaluated, but data were insufficient to set a reference value based on chronic disease outcomes according to set criteria (NASEM, 2019; Newberry et al., 2018). Instead, NASEM set an AI based on the highest median intake in U.S. dietary surveys (2600 mg/day for women and 3400 mg/day for men). EFSA set a health-based AI, as the evidence was not strong enough to set an AR (EFSA, 2016b). The EFSA AI is based on the associations between potassium and normal blood pressure and the risk of stroke. The NNR2023 Committee finds the link between potassium intakes and normal blood pressure well-established and supports the EFSA AI of 3500 mg/day for both men and women, including pregnant women. EFSA set an AI of 4000 mg/d for lactating women by adding the requirements for production of breastmilk corresponding to about 400 mg/day (EFSA, 2016b). The NNR Committee notes that the evidence for such a high requirement during lactation is limited and recommends 3500 mg of potassium also during lactation. AI is set to 3500 mg/day (females and males). Provisional AR is set to 2800 mg/day (females and males). Not sufficient data to derive UL.