My part in this Symposium on Vitamin Deficiencies is limited to the clinical manifestations of B1 hypovitaminosis. Beri-beri has long been regarded as the classical example of B1 hypovitaminosis. It would, therefore, be logical to discuss the prominent groups of symptoms associated with beri-beri. But, because it is difficult, even under experimental conditions, to exclude a single ingredient from the diet of man and, at the same time, to supply all other necessary food factors in abundance, it is to be expected, in any particular case of beri-beri, that the conditions which have caused this syndrome have also brought about more or less deficiency of substances other than B1. Therefore, it cannot be confidently asserted that all the symptoms which occur commonly in beri-beri are due to lack of vitamin B1. Still less is it possible to be sure that symptoms of less regular occurrence in beri-beri are attributable to lack of vitamin B1.
From the Thorndike Memorial Laboratory, Second and Fourth Medical Services (Harvard), Boston City Hospital and the Department of Comparative Pathology and Tropical Medicine of the Harvard School of Public Health.