Nephrolithiasis associated with the ketogenic diet

Purpose: The ketogenic diet has been used for treating seizure disorders fo r more than 70 years. Nephrolithiasis is a known complication of this diet with a reported stone rate as high as 10% but there is sparse literature de tailing the nature and treatment of these stones. We report on 4 children w ith nephrolithiasis on this diet. Materials and Methods: We describe stone treatment and analysis as well as metabolic and urine abnormalities in 4 children with nephrolithiasis on the ketogenic diet who presented to our institution. Results: All patients were treated with shock wave lithotripsy, fluid liber alization and oral citrate. One child was ultimately withdrawn from the die t due to persistent stone formation. Analysis revealed 3 calcium and 1 ammo nium urate stones. Three patients had hypercalciuria, 2 elevated urinary ur ic acid and 1 hypocitruria. Serum studies revealed acidosis in 3 cases. Conclusions: The ketogenic diet induces several metabolic abnormalities tha t increase the propensity for stone formation. Urologists should be aware o f this potential complication. Fluid liberalization and bicitrate are recom mended as prophylaxis.