STUDIES OF ANTIRICKETIC ACTIVITY IN SERA FROM PATIENTS WITH DISORDERS OF CALCIUM METABOLISM AND PRELIMINARY OBSERVATIONS ON THE MODE OF TRANSPORT OF VITAMIN D IN HUMAN SERUM*

Abstract

Proof of the curative action of vitamin D for rickets was established by the studies of many investigators (1, 2). It is now known that thera- peutic doses of this vitamin bring about increased calcium absorption from the intestinal tract (3), while massive doses induce hypercalcemia (4) and, experimentally at least, a combination of skeletal resorption and vigorous bone-matrix formation (5-7). Also, in the hypoparathyroid individual, administration of vitamin D results in an increased excretion of phosphorus and usually of calcium (8, 9).