An interventional study of Liberalized dietary potassium via fruits and vegetables and Standard dietary potassium restriction in Chronic Kidney Disease and Hyperkalemia, sponsored by University of Manitoba. Completed at 2 sites in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-17.
Sponsored by University of Manitoba · Not applicable, Interventional, and Treatment
The study will look at the impact of the potassium content in fruits and vegetables, on serum potassium concentrations in people with Chronic Kidney Disease (CKD) using a randomized crossover design. Participants will receive home delivery of fruit and vegetables with either higher or lower potassium content in a random order. Clinical chemistry markers from blood and urine samples, blood pressure, physical functioning and health related quality of life will be assessed throughout the duration of the trial. This study will also measure their physical functioning, using a chair stand test. The results of this study could change the dietary recommendations for people with CKD related to potassium.
The kidney is a primary site of potassium regulation in the body. Hyperkalemia, elevated serum potassium, occurs in approximately 10% of patients with chronic kidney disease (CKD) and is associated with elevated all-cause mortality. To minimize the risk of hyperkalemia, individuals with CKD are told to restrict dietary potassium. This recommendation is based on very-low quality evidence. Dietary potassium restrictions can negatively impact quality of life, and may put participants at risk of nutritional deficiencies so they should be based on good quality evidence. There is a need for high quality randomized controlled trials investigating the impact of dietary potassium modification on serum potassium concentrations in people with CKD.
This trial will evaluate the impact and safety of dietary potassium liberalization using fruit and vegetables on serum potassium concentrations in people with CKD. In this 16-week study, the investigators will test if changing the amount of potassium people with CKD are eating with fruits and vegetables changes the amount of potassium in their blood. The investigators will do this by providing people with fruits and vegetables that are either high or low in potassium for a period of 6 weeks. Then these same participants will be provided with fruits and vegetables that they didn't receive in the first 6 weeks, for an additional 6 weeks in what is called a randomized crossover design. In a randomized crossover design everyone gets both treatments, but the order they get them in is chosen at random, like a coin toss. Thirty participants will be recruited to this study. The investigators will measure blood potassium during the study and see if it changes due to the change in potassium in the fruit and vegetables provided. The investigators think that changing the amount of potassium that participants eat through fruit and vegetables will not lead to a different level of potassium in the participants blood, and that having higher potassium fruit and vegetables in the diet may lead to an increase in the participants quality of life. This study's results could change the dietary recommendation given to people living CKD and potentially allow them to eat a greater variety of food.
3,090 studies on the registry are indexed under Renal Insufficiency, Chronic; 698 are open to participants now.
This study's enrollment of 30 is below the median of 73 across 2,157 interventional studies indexed under Renal Insufficiency, Chronic.
Browse Renal Insufficiency, Chronic studies →University of Manitoba is the lead sponsor of 555 studies on the registry; 89 are open to participants now.
Of its 12 completed or terminated interventional studies of FDA-regulated products, 5 (42%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive weekly supplementation of higher potassium fruit and vegetables via grocery home delivery during the liberalized dietary potassium 2-week run-in and liberalized potassium treatment period, then cross-over to the restricted potassium treatment period following a 2-week washout period. Participants will receive a 30-60 minute dietary counseling session in the first week of each treatment period from a registered dietitian (RD), either in person or via videoconference, depending on regional Coronavirus disease (COVID)-19 restrictions and participant preference, which will outline the concepts of the dietary intervention. The RD will also recommend the best ways to prepare and include the fruit and vegetables into the participant's current diet.
Dietary Supplement: Liberalized dietary potassium via fruits and vegetables · Dietary Supplement: Standard dietary potassium restriction
Participants will receive weekly supplementation of higher potassium fruit and vegetables via grocery home delivery during the liberalized dietary potassium 2 week run-in and then start receiving a restricted potassium treatment period, then cross-over to the liberalized potassium treatment period following a 2-week washout period. Participants will receive a 30-60 minute dietary counseling session in the first week of each treatment period from a registered dietitian (RD), either in person or via videoconference, depending on regional COVID-19 restrictions and participant preference, which will outline the concepts of the dietary intervention. The RD will also recommend the best ways to prepare and include the fruit and vegetables into the participant's current diet
Dietary Supplement: Liberalized dietary potassium via fruits and vegetables · Dietary Supplement: Standard dietary potassium restriction
On the liberalized dietary potassium intervention, participants will receive groceries delivered to their houses that contain potassium rich fruit and vegetables, that contain more than 250 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 2000 mg of potassium a day from delivered fruit and vegetables, and a daily dietary potassium intake of 3500 mg.
Participants will receive weekly supplementation of lower potassium fruit and vegetables, that deliver less than 200 mg of potassium per typical serving. Participants will be instructed to incorporate the fruit and vegetables into their diet targeting a daily intake of 500 mg of K a day from the box, and a daily dietary K intake \< 2000 mg. Participants will receive counselling from a registered dietician (RD) to reinforce the potassium restriction.
Change in serum potassium concentrations between treatments
Serum potassium at the end of the liberalize dietary potassium period compared to the end of restricted dietary potassium period
Time frame: between endpoints of each experimental period (week 8 to week 16)
Change in physical function related quality of life between treatments
Participants will complete the SF-12 physical component score of the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire.
Time frame: between endpoints of each experimental period (week 8 to week 16)
Change in urinary potassium between treatments
total potassium concentration in mmol/L
Time frame: between endpoints of each experimental period (week 8 to week 16)
Change in urinary sodium between treatments
Total sodium concentration in mmol/L
Time frame: between endpoints of each experimental period (week 8 to week 16)
Urinary albumin to creatinine Ratio
calculated by dividing urinary albumin concentration in milligrams by urinary creatinine concentration in grams
Time frame: between endpoints of each experimental period (week 8 to week 16)
Urinary urea
Measured in mmol/L
Time frame: between endpoints of each experimental period (week 8 to week 16)
Urinary phosphate
Measured in mmol/L
Time frame: between endpoints of each experimental period (week 8 to week 16)
Hemoglobin A1c
Measure of glycosylated hemoglobin, hemoglobin A1c, expressed as a percentage
Time frame: between endpoints of each experimental period (week 8 to week 16)
Systolic blood pressure
Blood pressure will be measured in triplicate using a validated blood pressure monitor following Kidney Disease: Improving Global Outcomes (KDIGO) 2021 measurement guidelines, the average of the 2nd and 3rd measurements will be recorded.
Time frame: between endpoints of each experimental period (week 8 to week 16)
Diastolic blood pressure
Blood pressure will be measured in triplicate using a validated blood pressure monitor following KDIGO 2021 measurement guidelines, the average of the 2nd and 3rd measurements will be recorded.
Time frame: between endpoints of each experimental period (week 8 to week 16)
Five repetition chair stand time
Assessing physical functionality by asking participant to sit with arms folded in a chair and then stand up and sit down 5 times as fast as they can, time to complete is recorded.
Time frame: between endpoints of each experimental period (week 8 to week 16)
Dietary Intake
Dietary intake will be captured via triplicate dietary recall surveys using the Automated Self-Administered 24 hours Canada (ASA24, NCI, Rockville, Maryland, USA; http:// asa24. ca/)
Time frame: between endpoints of each experimental period (week 8 to week 16)
Plan to share: Yes — De-identified individual participant data (IPD)may be placed in a repository if required by a journal for publication purposes. De-identified IPD may also be requested from the principle investigator.
Supporting information: Study protocol, Informed consent form, Analytic code
Time frame: Data will become available following the publication of the primary results manuscript.
Access criteria: De-identified IPD may also be requested from the principle investigator upon reasonable request.
This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Renal Insufficiency, Chronic →