Citric acid's charged form, citrate, is most useful as mineral salts—especially potassium citrate—which strongly cut the return of calcium kidney stones and help dissolve uric acid stones. Salts also aid calcium and magnesium absorption and give a small exercise edge. Plain citric acid does far less, and can erode tooth enamel; longevity claims remain animal-only. (Full Review)
| Marker | Target | Why |
|---|---|---|
| 24-hour urinary citrate | >640 mg/day | Confirms citrate therapy is achieving its main goal |
| Urine pH | 6.0–6.5 (calcium); 6.5–7.0 (uric acid) | Guides alkali dosing and prevents over-alkalinization |
| Serum potassium | 4.0–4.5 mmol/L | Detects hyperkalemia from potassium citrate |
| Serum bicarbonate (CO2) | 22–28 mmol/L | Detects excess alkali load (metabolic alkalosis) |
| 24-hour urinary calcium | <200 mg/day | Tracks the calcium-lowering effect relevant to stones and bone |
| eGFR / serum creatinine | eGFR >90 mL/min/1.73 m² | Confirms kidney function is adequate for safe citrate salt use |
| Serum magnesium | 2.0–2.5 mg/dL | Relevant when using magnesium citrate or with diarrhea |
Cadence: Baseline before starting; recheck 6–12 weeks after starting or changing dose, then every 6–12 months once stable