To explore these gaps, we assessed whether associations between variants presumed to lower VDR bioactivity or contribute to vitamin D insufficiency, and ovarian cancer risk differed by predicted 25(OH)D status in a retrospective case–control study (New England Case–Control study, NECC) and two case–control studies nested within the prospective Nurses’ Health Study (NHS) and NHSII cohorts. The gene discussed is VDR; the disease is ovarian carcinoma.