vitamin d deficiency in high and low risk populations for esophageal cancer in northern iran

Background: diverse relationships have been proposed between esophageal cancer (ec) and vitamin d serum levels. we aimed to assess serum levels of vitamin d in high and low-risk populations for ec in northern iran. methods: this ecological study was conducted in golestan province, northern iran. based on the incidence rates of ec, the province was divided into high-risk and low-risk populations. a stratified cluster sampling method was used. serum vitamin d levels were assessed using the elisa method. the proportions of vitamin d deficiency were compared between the two populations. results: a total of 246 persons were studied, with a mean age of 50.7 years. 96 subjects were male (39%) and 146 subjects were female (61%). 119 subjects (48.8%) were from high-risk and 127 (51.6%) were from low-risk populations. thirty-two of 244 (13.1%) persons had vitamin d deficiency. the proportions of vitamin d deficiency were 7.9% and 18.3% in highand low-risk populations, respectively (p=0.02). conclusion: we found that significantly larger numbers of people suffered from vitamin d deficiency in populations at low-risk of ec compared to high-risk populations. regarding the ecological design of this study, causal inference could not be made from our results. therefore, we recommend further investigation of this issue in future individual-level studies in this area, and in other high-risk populations.