Clinical and statistical observations have led to the belief that sufficiently prolonged vitamin deficiency causes a reduction in the normal antimicrobic defense of the human body. From this it is concluded that administration of vitamins or vitamin-rich foods will lead to a restoration of normal antibacterial resistance in deficiency diseases and might even increase natural resistance in normal persons on nondeficiency diets. The present commercial exploitation of yeast and numerous other vitamin-containing foods, is based largely on the latter assumption. Adequate experimental evidence in support of advertised claims, however, is still lacking.
In order to prepare animals for a test of the currently alleged immunizing power of vitamins, Jusatz1 of the hygienic institute at the University of Marburg, Germany, fed growing rabbits on routine laboratory diets rendered vitamin free by prolonged pressure cooking at 120 C. Rabbits thus fed were arrested in their normal development and often remained at