What is the recommended diet for a patient with urolithiasis (kidney stones)?

From the Guidelines

A diet for urolithiasis (kidney stones) should focus on increased fluid intake of at least 2-3 liters of water daily to maintain dilute urine and prevent crystal formation. The American College of Physicians recommends management with increased fluid intake spread throughout the day to achieve at least 2 L of urine per day to prevent recurrent nephrolithiasis 1. Limit sodium consumption to less than 2,300 mg per day as high sodium increases calcium excretion in urine. For calcium stones, which are most common, moderate calcium intake (1,000-1,200 mg daily) from dietary sources is recommended rather than restriction, as normal calcium helps bind oxalate in the gut 1.

Some key points to consider:

• Reduce animal protein intake to 0.8-1 g/kg body weight daily, as excess protein increases stone-forming substances like uric acid and calcium.
• Limit oxalate-rich foods such as spinach, rhubarb, beets, nuts, chocolate, and tea if you have calcium oxalate stones.
• For uric acid stones, reduce purine-rich foods like organ meats, shellfish, and certain fish.
• Citrus fruits and juices should be consumed regularly as they contain citrate, which inhibits stone formation by binding to calcium.
• Avoid sugar-sweetened beverages and excessive vitamin C supplements (over 1,000 mg daily).
• These dietary modifications work by altering urine composition to create less favorable conditions for crystal formation and aggregation, thereby reducing the risk of new stone development or growth of existing stones.

It's essential to note that while these recommendations are based on the available evidence, the quality of evidence is sometimes limited, and more research is needed to fully understand the relationship between diet and kidney stone formation 1. However, following these guidelines can help reduce the risk of recurrent kidney stones and improve overall health outcomes.

From the FDA Drug Label

Throughout treatment, patients were instructed to stay on a sodium restricted diet (100 mEq/day) and to reduce oxalate intake (limited intake of nuts, dark roughage, chocolate and tea). A moderate calcium restriction (400-800 mg/day) was imposed on patients with hypercalciuria The recommended diet for a patient with urolithiasis (kidney stones) includes:

• Sodium restriction: 100 mEq/day
• Oxalate reduction: limited intake of nuts, dark roughage, chocolate, and tea
• Moderate calcium restriction: 400-800 mg/day for patients with hypercalciuria 2

From the Research

Dietary Recommendations for Urolithiasis Patients

• A daily fluid intake of 2.5-3.0 L/day or diuresis of 2.0-2.5 L/day is recommended to prevent recurrence of kidney stones 3, 4, 5, 6
• Not all beverages are beneficial, and some may even increase the risk of stone formation 4
• Dietary management, vitamins and supplements, physical activity are important components in reducing the risk of recurrent urolithiasis 4
• A detailed dietary assessment is recommended as dietary habits affect the faith of the disease 4

Specific Dietary Considerations

• In the case of hypercalciuria, a thiazide diuretic should be prescribed while in cases of hypocitraturia, potassium citrate should be given 3
• In the case of hyperoxaluria, the treatment depends on the type of hyperoxaluria, pyridoxine or calcium supplements with a meal can be offered 3
• For uric acid stone formers, alkali therapy is the standard of care whereas allopurinol can be beneficial in hyperuricosuric stone formers 3
• For cystine stone formers, increased fluid intake, restriction of sodium and animal protein ingestion, and urinary alkalinization are the standard therapies used 3
• High protein and fat intake are risk factors for urolithiasis, and a diet high in fat was associated with other urinary disturbances 6
• High or low calcium diet was associated with urolithiasis, and supplemental calcium is not a risk factor 6

Additional Considerations

• Potassium and magnesium citrate are potent in inhibiting the growth of stone fragments after extracorporeal shock wave lithotripsy 6
• Drinking hard water should be avoided, and tap water or low calcium content water is preferable 6
• Seasonal variations in temperature affected urinary volume, pH and relative saturation of uric acid, and patients should be aware of these changes 6