METABOLISM OF BONE SALTS IN RESISTANT RICKETS

Cases of rickets uncomplicated by renal disease which did not respond to the antirachitic treatment with ordinary doses of vitamin D have been reported by a number of investigators. 1 Chemical balance studies of the bone salt metabolism have been carried out in a number of these cases. 1f, g The changes in calcium and phosphorus metabolism have been reported to be not quite typical of ordinary infantile rickets but not at all like those of primary hyperparathyroidism. The urinary excretion of calcium has been reported to be above the level usually observed in active rickets. There is chemical evidence of a secondary hyperplasia of the parathyroids in this condition. Since hyperplasia of the parathyroids has been shown to be associated with rickets in experimental animals, this feature does not appear to be a unique characteristic of resistant rickets. The use of induced radioactive isotopes of the biologically important mineral