A recent randomized trial of antioxidants for cancer prevention found that daily supplementation with nutritionally appropriate doses of vitamins C and E, beta carotene, selenium and zinc appeared to increase the risk of melanoma in women four-fold, according to background information in the study. Because an estimated 48 percent to 55 percent of U.S. adults use vitamin or mineral supplements regularly, the potential harmful effects of these nutrients is alarming, said the authors.
Maryam M. Asgari, M.D., M.P.H., of Kaiser Permanente’s Division of
Research in Oakland, CA and colleagues examined the association between
antioxidants and melanoma among 69,671 women and men who were
participating in the Vitamins and Lifestyle (VITAL) study, designed to
examine supplement use and cancer risk. At the beginning of the study,
between 2000 and 2002, participants completed a 24-page questionnaire
about lifestyle factors, health history, diet, supplement use and other
cancer risk factors.
Intake of multivitamins and supplements during the previous 10 years,
including selenium and beta carotene, was not associated with melanoma
risk in either women or men. The researchers also examined the risk of
melanoma associated with long-term use of supplemental beta carotene and
selenium at doses comparable to the previous study and found no
“Consistent with the present results, case-control studies examining
blood levels of beta carotene, vitamin E and selenium did not find any
association with subsequent risk of melanoma,” said the authors.
“Moreover, the Nurses’ Health Study reported no association between
intake of vitamins A, C and E and melanoma risk in 162,000 women during
more than 1.6 million person-years of follow-up.”
This study was supported in part by a grant from the National Institute
of Arthritis Musculoskeletal and Skin Diseases and by grants from the
National Cancer Institute. Please see the study for additional
information, including other authors, author contributions and
affiliations, financial disclosures, funding and support, etc.