Stone types
- Calcium oxalate — the most common; influenced by urinary calcium, oxalate, citrate, and volume.
- Uric acid — associated with low urine pH, insulin resistance, and high animal-protein diets.
- Calcium phosphate — often associated with higher urine pH and certain medical conditions.
- Cystine — a rare genetic condition requiring specialty management.
Foundations of prevention
Hydration
Most stone-formers benefit from producing about 2.5 liters of urine daily. Water is the best fluid; citrate-rich beverages (like fresh lemon in water) may help selected patients.
Diet
Adequate dietary calcium (from food, taken with meals) binds oxalate in the gut and often reduces stone risk. Restrict added salt and moderate animal-protein intake. For calcium oxalate stones, moderate very high-oxalate foods (spinach, rhubarb, almonds in large amounts) while maintaining a nutritious diet — total elimination is usually unnecessary.
Salt intake
High sodium increases urinary calcium excretion. Most patients aim for under about 2,300 mg sodium/day.
Animal protein
Excess animal protein raises urinary uric acid and calcium and lowers citrate. Emphasize plant proteins and moderate meat portions.
Oxalate and citrate
Citrate inhibits stone formation. Potassium citrate — prescription or dietary — is a mainstay for many patients. Oxalate management depends on stone type and 24-hour urine testing.
Adjunctive supplements — individualized to stone type
- Magnesium — may modestly reduce calcium oxalate risk in selected patients.
- Vitamin B6 — studied for hyperoxaluria in specific contexts.
- Potassium citrate (prescription) — an alkalinizing therapy for many stone types.
- Probiotics — an evolving area, particularly for oxalate metabolism.
Do not initiate high-dose vitamin C, vitamin D, or calcium supplementation without clinician guidance if you form stones. A 24-hour urine study and stone analysis should drive personalized recommendations.