Chemical Composition of the Urine in the Normal Black and White Population

The prevalence of nephrolithiasis in white males and females is 12 and 5% respectively, and in blacks is <1%. In order to further investigate these striking discrepancies we compared dietary intake, serum values, urine solute, inhibitor content and Ca: Creat ratios before and after ingestion of a diet consisting of a standard intake of Na (100 mmol/24 hr) and Ca (400 mg/24 hr), in 31 (19F and 12M) recently urbanized blacks and 29 (17F and 12M) white age-matched volunteers. Glycosaminoglycans were measured on earlv morning urines by glucuronic acid determination.