The value of standard diet in urolithiasis.

The excretion of magnesium, calcium, zinc and citric acid was determined in the urine of 11 patients with urinary calculi and in 5 healthy subjects on a standard diet for a period of 5 days. It was found that there was more or less distinct dependence of electrolytes and citric acid on the standard diet. In order to obtain accurate results, mineral metabolism in stone patients can only be investigated under defined conditions (i.e. the standard diet). The excretion of magnesium and citric acid in the urine was reduced in patients with calcium oxalate stone, while that of calcium and zinc was increased.