[Idiopathic hypercalciuria: effects of acute phosphorus deficiency (author's transl)]

Eleven patients with kidney stone disease and idiopathic hypercalciuria (urinary calcium above 4 mg/kg/j), without phosphorus renal leak and 6 control subjects have been put for 3 days on a diet containing 1 g calcium and 1 phosphorus daily (period A), and then for 4 days on a diet containing 1 g calcium, 450 mg phosphorus and 3 g aluminium hydroxyde daily (period B). During period A, no significant difference in blood calcium, phosphorus and magnesium, not in phosphaturia, rate of phosphorus reabsorption (RPR) and ratio maximum RPR/creatinine clearance was found between the two groups. After 2 days on a low phosphate diet (period B) the blood phosphorus decreased significantly in the hypercalciuric patients but not in the control subjects, thus revealing among the forme a latent abnormality in the retention of phosphates. This abnormality could play an important role in the pathogenesis of hypercalciuria.