Enhanced renal tubular calcium reabsorption independent of parathormone activity, in children on long term anticonvulsant therapy.

A significant reduction in the urinary calcium-creatinine ratio, was found in thirty-four ambulatory epileptic children on long term anticonvulsant therapy, studied during wintertime. No significant difference in the urinary excretion of cyclic AMP, phosphate or amino-acids was observed when the study-group was compared to an age-matched control group. Serum calcium and phosphate values were normal, but a significant increment in alkaline phosphatase was noted. Since there was no evidence of hyperactivity of the parathormone, it is suggested that the enhanced renal tubular calcium reabsorption in children on long term anticonvulsant therapy is a nonparathormone mediated phenomenon, possibly compensating for reduced calcium absorption in the gastrointestinal tract.