THE “VITAMINE” HYPOTHESIS AND DEFICIENCY DISEASES

Abstract

An elaborate experimental inquiry into the cause of the failure of rats to grow or to maintain life long when restricted to a diet of purified proteins, carbohydrates, fats, and inorganic salts led McCoUum and Davis' to the conclusion that there were lacking in such food mixtures two substances or groups of substances, the chemical natures of which are still unknown, and which must be regarded as dietary essentials.McCollum and Kennedy,2 after pointing out several reasons why the term "vitamine," introduced by Funk,3 was unsatisfactory as a name by which to designate them, proposed the provisional terms "fatsoluble A" and "water-soluble B."The first is soluble in fats and is found in abundance in butter fat, egg fat, the ether extract from kidney, and also in considerable amounts in the leaves of plants, but in general in amounts too small in the seeds to supply the need of a growing animal.The second, which is soluble in water and in alcohol, has been shown to be present in abundance in wheat,l wheat germ," maize,6 alfalfa leaves,' and cabbage as well as in several foods of animal origin.Funk* postulated the existence of a number of chemical substances essential in the diet, the absence of a single one of which would cause abnormal metabolism, in one case polyneuritis, another scurvy, another pellagra, and another rickets.He assumes that still other unidentified substances may be essential to growth.We recognized the possibility that our extracts which