Association between dietary vitamin C and risk of cutaneous melanoma in a population of Northern Italy.

Cutaneous melanoma incidence has been increasing during the last few years, and diet has been suggested as one of the lifestyle factors responsible for this increase. Since antioxidant nutrients such as ascorbic acid might prevent skin carcinogenesis, we investigated the risk of cutaneous melanoma related to vitamin C intake in a population-based case-control study in Northern Italy based on 380 melanoma patients and 719 matched controls, to whom we administered a semiquantitative food-frequency questionnaire. After adjusting for potential confounders, odds ratio of melanoma were 0.86 (95 % confidence interval 0.65 - 1.15) and 0.59 (95 % confidence interval 0.37 - 0.94) in the intermediate and highest categories of vitamin C dietary intake respectively, compared with the bottom one. The association between vitamin C and decreased risk persisted after adjustment for some potential confounders. In age- and gender-stratified analyses, this association was seen in young females (< 60 years old), and was found to be enhanced in subjects with phototypes II and III. These results suggest a possible protective activity of vitamin C intake against cutaneous melanoma in specific subgroups of this population of Northern Italy.