Sex disparities in vitamin D status and the impact on systemic inflammation and survival in rectal cancer

BackgroundWe reported previously that rectal cancer patients given curative-intent chemotherapy, radiation, and surgery for non-metastatic disease had enhanced risk of metastatic progression and death if circulating levels of 25-hydroxyvitamin D [25(OH) D] were low. Here we investigated whether the association between the vitamin D status and prognosis pertains to the general, unselected population of rectal cancer patients.MethodsSerum 25(OH) D at the time of diagnosis was assessed in 129 patients, enrolled 2013-2017 and representing the entire range of rectal cancer stages, and analyzed with respect to season, sex, systemic inflammation, and survival.ResultsIn the population-based cohort residing at latitude 60 degrees N, 25(OH) D varied according to season in men only, who were overrepresented among the vitamin D-deficient (