AN APPRAISAL OF ANTIRACHITICS IN TERMS OF RAT AND CLINICAL UNITS

Abstract

It has become increasingly evident that there are now available a considerable number of valuable, indeed almost specific, agents for the prevention of rickets. This fact needs no additional confirmation except in detail: There are, in all, five reliable and well established antirachitics, each one of which represents a distinct and different pharmacologic point of view. The first to be established was cod liver oil, a natural product; the second to be introduced was direct irradiation of the body by means of ultraviolet energy; the third was irradiated food, particularly milk, activated by exposure to ultraviolet radiations; the fourth, an irradiated basic substance, ergosterol, extracted from yeast; the fifth, representing still another method, was "yeast milk," a biologic product endowed with antirachitic potency as the result of feeding irradiated yeast to the cow. In addition to these five established agents there are numerous others which consist of various modifications or