Purpose: The ketogenic diet has been used for treating seizure disorders for 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 detailing the nature and treatment of these stones. We report on 4 children with 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 liberalization and oral citrate. One child was ultimately withdrawn from the diet due to persistent stone formation. Analysis revealed 3 calcium and 1 ammonium urate stones. Three patients had hypercalciuria, 2 elevated urinary uric acid and 1 hypocitruria. Serum studies revealed acidosis in 3 cases.
Conclusions: The ketogenic diet induces several metabolic abnormalities that increase the propensity for stone formation. Urologists should be aware of this potential complication. Fluid liberalization and bicitrate are recommended as prophylaxis.