ABSTRACT
Guinea pigs were maintained for various periods of time on low (0.5 mg/day), intermediate (20 mg/day), or high (100 and 500 mg/day) levels of dietary ascorbic acid. Animals in each experimental group were challenged with Candida albicans via cardiac injection, and the course of infection in the kidneys was assessed. The results show that the animals receiving only 0.5 mg of ascorbic acid per day were significantly more susceptible to the infection than animals maintained on any higher level of dietary ascorbic acid. The greater susceptibility of the guinea pigs in the 0.5-mg level group was evident, however, only during "early" stages of the infection (until about day 3). Guinea pigs receiving high levels of dietary ascorbic acid were no more resistant at any time after infection, or with any challenge dose, than those receiving an intermediate dietary level. Although these data suggest that vitamin C may be involved in resistance to candidiasis, tissue levels of ascorbic acid do not change significantly with time after infection. These results indicate that low levels of dietary ascorbic acid increase susceptibility to candidiasis, yet high (or "megadose") levels of dietary vitamin C do not show any effect on resistance to this microorganism.