ANTIRACHITIC ACTIVITY OF IRRADIATED CHOLESTEROL, ERGOSTEROL AND ALLIED SUBSTANCES

Abstract

About three years has elapsed since it was shown in this laboratory that vegetable oils can be rendered highly antirachitic by irradiation with ultraviolet rays.¹Similar results were reported by Steenbock and his co-workers.²In the course of a large series of experiments it soon developed that vegetables can be activated by this means, and furthermore that when they have been thus transformed—for example, carrots or spinach—they retain their antirachitic potency even after being cooked. The problem rapidly assumed a chemical aspect, for it was found that the underlying chemical substance in the oils or vegetables which enabled them to be energized in this striking way was the cholesterol in the animal cell, or its counterpart, the phytosterol, in the vegetable cell. The antirachitic action of the various irradiated foods and chemical substances was established in the laboratory and in the clinic. From a therapeutic point of view