Clinical Research Directory

Inclusion Criteria: Calcium phosphate (CaP) stone participants: * Age 18-70 * History of at least one calcium phosphate (hydroxyapatite) stone * Defined as at least 50% of stone material on most recent stone analysis Calcium oxalate (CaOx) stone participants: * Age 18-70 * History of at least one calcium oxalate stone * Defined as at least 50% of stone material on most recent stone analysis. Other inclusion criteria considerations: The investigators will study balanced numbers of male and females. Prior studies did not have balanced representation of male and female sexes. In prior studies, less than 40% were female, or sex data is not presented. Study of both male and female sex is crucial with kidney stones and therapies that affect citrate and pH because there are well established epidemiologic differences in stone type and physiologic differences in acid-base handling by sex. Epidemiologically, younger women are more likely to have CaP stones, and this is likely because they have higher urine pH. Exclusion Criteria: * History of primarily brushite, uric acid, cysteine, or struvite stones * History of severe acid-base abnormality, very low (less than 100mg/day) or very high (greater than 1500mg/day) urine citrate * Participants who cannot stop diuretic medication or alkali supplementation for the course of the study period * Use of drugs that can directly affect proximal tubule function (e.g., topiramate) * Diagnosis of complete distal renal tubular acidosis * Diagnosis of chronic kidney disease (eGFR \<60 mL/min/1.73m²)