Abstract

Within the two Nurses' Health Study cohorts of US women, we examined whether higher intakes of vitamin C, vitamin E, retinol, or individual tocopherols or carotenoids are associated with a lower risk of melanoma. We confirmed 414 cases of invasive melanoma among over 162,000 Caucasian women aged 25-77 years during more than 1.6 million person-years of follow-up. Diet was measured every 4 years with a food frequency questionnaire and supplement use was reported every 2 years. Several measures of sun sensitivity were assessed and included in proportional hazards models. We found that vitamins A, C, E and their individual components were not associated with a lower risk of melanoma. Only retinol intake from foods plus supplements appeared protective within a subgroup of women who were otherwise at low risk based on nondietary factors (relative risk (RR)=0.39, 95% confidence interval (CI) 0.22-0.71 for >/=1,800 vs 400 microg day(-1), P for linear trend=0.01). Contrary to expectation, we observed higher risks of melanoma with greater intakes of vitamin C from food only (RR=1.43, 95% CI 1.01-2.00 for >/=175 vs <90 mg day(-1), P for linear trend=0.05) and a significant positive dose-response with frequency of orange juice consumption (P=0.008). Further research is needed to determine whether another component in foods such as orange juice may contribute to an increase in risk.