A Growth Deficiency Disease, Curable by Wheat Germ Oil*

The advances made in the purification of the vitamins have provided an improved method of approach toward the study of the number, as well as nature, of the essential food factors. Because of the uncertain composition of the vitamin B complex, it is as yet very difficult to test for additional water-soluble components of the ultimate purified diet. The fat-soluble group, however, appears less complex, and presents a promising field for the investigation of the possible existence of additional vitaminlike factors. A satisfactory basal ration may be supplied by fat-free casein, sucrose, and salts; to these constituents may be added a fat-free yeast to provide the water-soluble components necessary for the rat, an animal which is able to synthesize vitamin C. Through the use of carotene, irradiated ergosterol, and a linolate (l), a diet may be provided with fat-soluble vitamins A and D, and the essential unsaturated fatty acid (vitamin F), in practically pure form. The nature of the metabolic factor in lard reported by Wesson (2) is obscure, but its omission does not appear to affect growth. The remaining consideration is vitamin E, to which a subtle late growth stimulus has been attributed by Evans (3). Since this effect is not reported to become well evident until after the 8th month of life, and is marked only after a year, the absence of the vitamin should cause sterility but should not influence growth until the maturity “plateau” is reached.