The relationship between vitamin C and cancer is complex, and some parts of the connection are not fully understood. It is thought that vitamin C, especially as part of healthy diet, may help prevent cancer. There is some evidence that people who have higher levels of vitamin C are less likely to get cancer. Very high doses of vitamin C have been studied as a way to improve the health of terminally ill cancer patients and possibly extend their lives. Vitamin C, like other single vitamins, is not a cure for cancer.
People who regularly eat foods rich in vitamin C may have a lower risk of cancer, including some cancers of the digestive tract. Vitamin C and cancer maybe be related because vitamin C acts as an antioxidant. In this role, it may help prevent the damage to deoxyribonucleic acid (DNA) that causes the mutations at the heart of many cancers. Also, consuming vitamin C in the diet may help neutralize the carcinogens found in processed meats. These carcinogens may contribute to stomach cancer. Foods high in vitamin C are also usually high in other kinds of natural antioxidants, which could be another connection.
Supplements have been studied for their connection between vitamin C and cancer. There is some evidence that vitamin C may help prevent the formation of cancer cells in the skin, lungs, and cervix, among other places. Researchers have studied isolated vitamin C in connection to cancer in order to better understand how it might prevent tumor growth.
Vitamin C and cancer have been studied together to determine whether C has a role in cancer treatment. Large amounts of vitamin C, up to 10 grams daily, have shown some promise in helping to extend the lives of people with terminal cancers. Not all studies have found this to be the case or have been able to reproduce the same results. None of the patients in these studies were cured, as all eventually succumbed to cancer. It isn't known what effect vitamin C might have in the treatment of early stages of cancer.
Some cancer patients may have low levels of vitamin C. This connection between vitamin C and cancer isn't well understood. Chemotherapy may deplete vitamin C in cancer patients undergoing treatment, which could contribute to the side effects of chemotherapy. People undergoing treatment should ask about taking supplements, which could lower the effectiveness of some drugs.
