Investigations during the past few years have indicated that vitamin C plays an important part in determining the resistance of the animal organism to certain types of bacterial infections and toxins. For example, guinea-pigs fed a ration deficient in the vitamin are much less resistant to diphtheria toxin than are normal control animals; similarly, the administration of vitamin C (cevitamic acid) to normal guinea-pigs increases their resistance to the toxin.1 A protective effect of vitamin C against tuberculous infections in animals has likewise been described repeatedly. Decreased resistance to tuberculous infection develops in animals fed a vitamin C deficient diet and, conversely, an increased susceptibility to acute scurvy is seen in infected animals.
The comparatively recent introduction of methods for the determination of vitamin C and for following the intake and excretion of the vitamin has made possible studies on the metabolism of this substance in human subjects. As