Background:There is increasing interest in the possible association between cancer incidence and vitamin D through its role as a regulator of cell growth and differentiation. Epidemiological studies in adults and one paediatric study suggest an inverse association between sunlight exposure and cancer incidence.Methods:We carried out an ecological study using childhood cancer registry data and two population-level surrogates of sunlight exposure, (1) latitude of the registry city or population centroid of the registry nation and (2) annual solar radiation. All models were adjusted for nation-level socioeconomic status using socioeconomic indicators.Results:Latitude and radiation were significantly associated with cancer incidence, and the direction of association was consistent between the surrogates. Findings were not consistent across tumour types.Conclusion:Our ecological study offers some evidence to support an association between sunlight exposure and risk of childhood cancer.
Bibliographical noteFunding Information:
This work was supported by the National Institutes of Health Pediatric Cancer Epidemiology Training Grant T32 CA099936 and the Children’s Cancer Research Fund, Minneapolis, MN, USA
- childhood cancer
- vitamin D