Epidemiologic evidence of a protective effect of vitamin C for non-hormone-dependent cancers is strong. Of the 46 such studies in which a dietary vitamin C index was calculated, 33 found statistically significant protection, with high intake conferring approximately a twofold protective effect compared with low intake.
Approximately 90 epidemiologic studies have examined the role of vitamin C or vitamin–C-rich foods in cancer prevention, and the vast majority have found statistically significant protective effects. Evidence is strong for cancers of the esophagus, oral cavity, stomach, and pancreas.
Am J Clin Nutr. 1995 Dec;62(6 Suppl):1385S-1392S. doi: 10.1093/ajcn/62.6.
ABSTRACT. Epidemiologic evidence of a protective effect of vitamin. C for non-
Vitamin C and cancer prevention: the epidemiologic evidence. Am J Clin Nutr 53: 270S-282S Epidemiologic evidence of a protective effect of vitamin C for .