Antirachitic Properties of A.T. 10 for the Rat and Chicken

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*

“…The method of assay used in these experiments consisted of a comparison of the antiricketic effect of test substance with the effects of known amounts of vitamin D in ricketic rats. One must recall that dihydrotachysterol has, in man, hypercalcemic effects approximately equal to those of calciferol mg. for mg. (37,38), yet this compound is only 1/400 (or less) as potent an antiricketic substance as calciferol when fed to the rat (39,40). Thus, our data do not negate the possibility that some agents differing only slightly from vitamin D may at times be etiologically important in the genesis of hypercalcemia.…”