Evaluation of vitamin A and C status in normal and malignant conditions and their possible role in cancer prevention.
A comparative study has been made on the levels of vitamins A and C in normal and malignant conditions in human and murine subjects. Further, the effect of supplemental vitamins A and C on tumor take, host-survival and tumor growth have been studied in a number of transplantable and induced tumors in mice. The vitamins were assayed in sera samples from normal subjects, patients with cancer of the uterine cervix or ovary, and leukemia and lymphoma patients. Among the murine group the tumors included sarcoma 180 in solid and ascitic form, benzo[a]pyrene-induced fibrosarcoma, Dalton's ascitic lymphoma and Schwartz lymphoblastic leukemia. The serum level of vitamin C was found to be lower than that of the normal controls in all cases studied. The level of vitamin A was found to be higher in cancer patients in the human group and lower in the murine group when compared with their normal controls. Studies on murine tumors showed that supplementary vitamins administered at the initial phase of tumor development reduced the percentage tumor take and the rate of tumor growth, and improved host survival, indicating that these vitamins have a protective role in the murine system.