Evaluation of breast cancer in Iranian women in an ecological study based on latitude, sun exposure and vitamin D intake

Breast cancer is the most common cancer and the major factor of death from cancer in women worldwide and also it is the most common cancer among women in Iran. Many studies suggest that breast cancer is associated with latitude، sunlight and vitamin D. This study was conducted with aim to ecologically evaluate breast cancer in Iranian women based on geographical latitude، exposure to sunlight and vitamin D. This ecological study is was performed in 2014 with aim to evaluate the relationship between breast cancer in Iranian women and some effective factors such as latitude، exposure to sunlight and vitamin D. For this purpose، we used National Cancer Registry data، Iran segmentation map based on latitude، distribution of prevalence of vitamin D deficiency based on the results of the study of SaeidNia، and mean hours of sunlight which was collected by the Meteorological Agency. in lower latitudes especially at 20 to25 degrees which the incidence of breast cancer is lower، the prevalence of vitamin D deficiency is lower and mean hours of sunlight is higher than higher latitudes. There is negative association between the incidence of breast cancer، latitude، hours of exposure to sunlight and vitamin D intake. However، analytical studies will be needed to achieve scientific inferences.