Reliability of self-reported sun exposure in Canadian women and estimation of lifetime exposure to vitamin D from sun and diet.

Objective: To assess the inter-method reliability of the Ovarian Cancer in Alberta (OVAL) survey developed to estimate adult vitamin D exposure from sun and diet for every tenth year, against the longer Geraldton Skin Cancer Prevention Survey (the assumed 'gold standard'). We also estimated total vitamin D exposure using the OVAL survey.

Design: A randomized crossover design to assess the inter-method reliability of sun exposure (OVAL v.