Does CKD Require Restricting Potassium-Rich Foods? With Navdeep Tangri, MD

Urinary potassium excretion rose on a liberalized produce diet, while serum potassium did not differ significantly compared with a restricted diet.

Patients with chronic kidney disease (CKD) are often advised to limit potassium-rich fruits and vegetables. In a randomized crossover trial, increasing potassium intake through these foods did not produce a statistically significant increase in serum potassium compared with a restricted diet.¹

Navdeep Tangri, MD, professor of medicine at the University of Manitoba in Canada, presented the findings at the American Society of Nephrology (ASN) Kidney Week 2026 in Denver, Colorado. In an interview with HCPLive, he highlighted the disconnect between dietary potassium intake, urinary potassium excretion, and blood potassium concentrations.

“I think all of us, when we go back to our physiology textbooks, know that most potassium in the body is not in the blood; it’s inside cells,” Tangri said. “And this goes to show that the link between what you eat, particularly dietary potassium from fruits and vegetables, and what you see in the blood is not as strong as we perhaps think it is.”

Serum Potassium Did Not Differ Significantly Between Diets

The open-label trial randomized 30 adults in Winnipeg, Canada, with an estimated glomerular filtration rate (eGFR) of 15–45 mL/min/1.73 m² and serum potassium concentrations of 4.5–5.5 mEq/L.¹

Because dietary interventions depend on what participants actually eat, investigators delivered groceries to their homes each week. High-potassium produce supported a liberalized intervention targeting 2000 mg/day of potassium from fruits and vegetables, while low-potassium produce supported a standard intervention targeting 500 mg/day.

After a 2-week liberalized run-in, participants completed 6 weeks on each intervention in randomized order, separated by a 2-week washout.¹

Serum potassium, the primary outcome, did not differ significantly between diets (mean difference, −0.014 mEq/L; 95% CI, −0.199 to 0.171; P = .875).

Urinary potassium excretion was significantly greater during the liberalized intervention (mean difference, 15.464; 95% CI, 7.606–23.323; P < .001), consistent with increased potassium consumption. The ASN abstract did not specify the unit for this difference. Quality of life, physical function, blood pressure, and other biochemical outcomes also showed no statistically significant differences.¹

“I think the most notable thing that stood out to me was the big change in urinary potassium, but very little change in the blood potassium,” Tangri said.

Why Potassium Restriction Advice Persists in CKD

Hyperkalemia occurs in approximately 10% of individuals with CKD and is associated with increased all-cause mortality.² Concerns about elevated serum potassium have contributed to longstanding recommendations to restrict potassium-rich foods, although the evidence supporting broad dietary restrictions has been limited.²

Tangri said these recommendations can leave patients fearful of consuming potassium, even when their serum potassium concentrations are normal.

He described how patients searching for kidney-friendly diets may encounter advice emphasizing potassium restriction before receiving individualized nutritional guidance. In his view, this can discourage the consumption of fruits and vegetables that otherwise contribute to cardiovascular and kidney health.

The randomized crossover trial was designed to test whether increasing potassium specifically through fruits and vegetables would meaningfully affect serum potassium in patients with reduced kidney function.

Which Patients With CKD the Findings Apply To

Tangri suggested that restricting potassium from fruits and vegetables may be unnecessary for many patients with CKD, although he acknowledged that dietary management must account for individual hyperkalemia risk.

The trial was small and short, with only 30 randomized participants and 6 weeks of exposure to each intervention. Participants also had serum potassium concentrations of 5.5 mEq/L or lower at enrollment. These findings therefore cannot establish the long-term safety of dietary liberalization or its applicability to all patients with CKD.¹

Hyperkalemia events were reported. Two participants developed hyperkalemia during the run-in period, and 1 event occurred during the liberalized intervention compared with none during the standard intervention. Two participants did not complete the final visit, including 1 following sudden cardiac death and 1 because of hyperkalemia. The abstract did not establish whether these events were related to the intervention.¹

Tangri also distinguished potassium naturally present in fruits and vegetables from potassium additives in processed foods, noting that the source of dietary potassium may influence its effects.

He suggested that the potential blood pressure and cardiovascular benefits of fruits and vegetables should be considered alongside hyperkalemia risk when counseling patients.

Although the study did not demonstrate that liberalized and restricted diets are equivalent, its findings raise questions about whether blanket restrictions on potassium-rich produce are necessary for appropriately selected patients with CKD.

Editor's Note: Disclosures for Navdeep Tangri, MD, include AstraZeneca, Bayer, Boehringer Ingelheim, ClinPredict, Eli Lilly and Company, GSK, Janssen Pharmaceuticals, Klinrisk, Marizyme, Mesentech, Otsuka Pharmaceutical, ProKidney, PulseData, Quanta, Renibus Therapeutics, Roche, Tricida, and Vera.

References

1. Tangri N, Seniuk B, Hager D, et al. Dietary potassium liberalization with fruits and vegetables in people with CKD: a randomized crossover clinical trial. Abstract presented at: American Society of Nephrology Kidney Week 2026; October 22-25, 2026; Denver, CO. Abstract TH-PO1247. doi:10.1681/ASN.2026t1yq1btf

2. Iman Y, Balshaw R, Alexiuk M, et al. Dietary potassium liberalization with fruit and vegetables versus potassium restriction in people with chronic kidney disease (DK-Lib CKD): a clinical trial protocol. BMC Nephrol. 2023;24(1):301. doi:10.1186/s12882-023-03354-4