Potassium citrate effects on kidney handling of oxalate and citrate in adults

Oxalate and Citrate in Humans - Response to Citrate

Not applicable Interventional University of Chicago · NCT06944223

This project will test whether a single oral dose of potassium citrate changes how the kidneys handle oxalate and citrate in adults with and without calcium oxalate kidney stones.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorUniversity of Chicago Academic / other
Locations1 site (Chicago, Illinois)
Trial IDNCT06944223 on ClinicalTrials.gov

What this trial studies

At the University of Chicago Clinical Research Center, investigators will enroll two groups of 12 adults each: people with a history of calcium oxalate kidney stones and people without stones and with normal 24‑hour urine oxalate. Participants will receive a single oral dose of potassium citrate and have blood and urine collected over six hours to measure fractional excretion of oxalate and citrate. Changes from baseline will be compared and oxalate fractional excretion will be adjusted for changes in citrate to test a possible transporter-mediated link between the two ions. Key exclusions include non–calcium stone types, significant chronic kidney disease (eGFR <75 mL/min/1.73 m²), extreme urine citrate values, and inability to stop diuretics or alkali supplements.

Who should consider this trial

Good fit: Adults 18–70 who either have at least one calcium-based kidney stone or have no stone history with normal 24‑hour urine oxalate, can stop diuretics/alkali for the study, and have preserved kidney function are ideal candidates.

Not a fit: People with primarily uric acid, cystine, or struvite stones, significant CKD (eGFR <75 mL/min/1.73 m²), extreme urine citrate levels, or who cannot stop diuretics/alkali are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, the results could clarify a transporter link between citrate and oxalate and guide better prevention strategies for calcium oxalate kidney stones.

How similar studies have performed: Prior research shows citrate changes urinary chemistry and can reduce stone risk, but the specific transporter-mediated coupling between oxalate and citrate in humans remains largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Stone formers (SF):

* Age 18-70
* History of at least one calcium-based kidney stone

Non-stone formers (NSF):

* Age 18-70
* No history of kidney stone
* 24-hour urine oxalate within laboratory normal range (\<50 mg/day)

Exclusion Criteria:

History of primarily uric acid, cysteine, or struvite stones

History of severe acid-base abnormality, very low (less than 100 mg/day) or very high (greater than 1500 mg/day) urine citrate

Any controls or stone former (SF) participants who cannot stop diuretic medication or alkali supplementation for the course of the study period

Chronic kidney disease (glomerular filtration rate \<75 milliliters per minute per 1.73 square meters \[mL/min/1.73 m²\])

Non-stone formers (NSF) and stone formers (SF) with extreme levels of urine citrate will be excluded from this small initial study to reduce heterogeneity and remove focus from the extremes of citrate levels.

Where this trial is running

Chicago, Illinois

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Kidney StoneHealthykidney stonekidney stones
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.