Recent Studies in the Physiology of Vitamin B *

The idea that disease may result from the lack of an essential nutrient is now well established. The pioneer work in this field concerned those disorders that seemed to be related in some way to diet. In this category belongs the disease beriberi which is of widespread occurrence in the Far East among people whose staple food is white rice. In his monograph, Vedder (1913) championed the idea that beriberi is caused by the lack of a specific vitamin substance. Many clinicians, however, especially among the Japanese (Ogato et al, I923), hesitate to concur in this opinion because experimental beriberi in animals differs in certain respects from human beriberi as seen in the clinic. In this connection, it is worth while to point out that the laboratory worker endeavors, as far as possible, to limit the variables involved in the problem under consideration, and, as a consequence, he may expect to produce syndromes in experimental animals differing in certain respects from the symptom-complex seen in the clinic. The case observed by the clinician, on the other hand, is more likely to be the result of a multiple rather than a single deficiency. As an illustration, consider "wet" and "dry" beriberi. The neuromuscular symptoms in these two conditions are practically the same, but the presence or absence of edema calls for explanation. It is not likely that the many individuals observed in the clinic have subsisted on essentially the same diet, as have, for example, a group of rats fed a particular experimental ration. Studies of edema indicate that this condition is associated with a low concentration of blood plasma proteins, and edema has been produced experimentally by feeding diets low in protein for extended periods (Harden and Zilva, 1919; Kohman, 1920). It is conceivable, although as yet undetermined, that cases of "wet" beriberi are suffering not only from a deficiency of a particular vitamin but from a shortage of protein as well.