[TanyaRD]

The role of vitamin C in cancer treatment and prevention remains unclear. Some studies have demonstrated that high doses of supplemental vitamin C can interfere with the effectiveness of certain chemotherapy agents (From MSK: Vitamin C can reduce the effectiveness of many antineoplastic agents, include vincristine, doxorubicin, methotrexate, cisplatin, and imatinib.) The amount of vitamin C consumed in the average diet is not enough to worry about. I do not advise my patients to avoid fruits and vegetables during chemo/xrt treatment but discourage use of vitamin C supplements as a precaution. I do caution against some of the special formulated juices (including excessive homemade juicing) designed for a high dose of antioxidants. Even when chemotherapy is complete I do not put vitamin C supplementation at the top of my list due to limited and conflicting research on the benefits. I would rather my patients obtain the vitamin c and other nutrients in their diet. We have a lot of definitive research demonstrating the benefits of high fruit/vegetable intake in breast cancer.