Hydroxycarboxylate Malabsorption and Calcium Oxalate Nephrolithiasis

In Queensland, Australia, there is a high incidence of calcium nephrolithiasis (16.8 hospital admissions per 10,000 population) which is among the highest incidences reported for Westernized societies (1). Our initial investigation of 40 recurrent calcium-oxalate stone formers indicated that they have significantly elevated urinary oxalate and calcium excretions and decreased excretions of ascorbate and citrate (1). The raised oxalate excretion was shown not to be due to a hyperactive 2-carbon pathway, or to be derived from fat or carbohydrate metabolism (2).