Dietary factors in the pathogenesis and prophylaxis of calcium nephrolithiasis

Abstract

A 47-year-old man, an executive at a financial institution, entered the hospital for the evaluation of recurrent nephrolithiasis and the spontaneous passage of a renal stone 3 months previously. The patient had been in good health except for a 15-year history of recurrent renal stones. The stones, which had occurred bilaterally, had been passed at a rate of 5 per year for the last 5 years; in the first 10 years he had passed a total of 5 stones. The patient had undergone cystoscopy with stone extraction on three occasions and recently had been treated with extracorporeal shock-wave lithotripsy for a partially obstructing stone in the left proximal ureter. Crystallographic analysis of these stones had revealed that were composed of 100% calcium oxalate monoand dihydrate. Radiography disclosed continuing stone formation by documenting the presence of new stones during the preceding 8 months. The patient had no history of gastrointestinal disease, excessive sun exposure, or current drug usage, including antacids and vitamin supplements. He had never received neck irradiation, nor had he experienced a urinary tract infection, His father and paternal uncle both had passed kidney stones of unknown type. The patient had undergone multiple evaluations for the cause of his stone diathesis but always had been told that all studies were normal. He was specifically told that hypercalcemia had never been detected. Review of his diet by a dietician showed that he usually consumed 110 g of protein/day, with an 80 g intake of animal protein. His calcium