Nickan Research Institute Immunopathologia Persa 2423-8015 4 2 2018 07 01 Vitamin D and cancer; a contradictory problem e13 e13 10.15171/ipp.2018.13 EN Masoud Amiri EDITORIAL 10.15171/ipp.2018.13 2017 12 02 2018 01 03 Vitamin D has been reported as an essential factor for bone health as well as a protective factor for many cancers, with potential effect of the pandemic situation of vitamin D deficiency worldwide. Vitamin D could affect every cell in the human body. Living at higher latitudes and having vitamin D deficiency could result in increasing risk of common fatal cancers. Enough intake of vitamin D could have a beneficial influence on some cancers such as cancers of colon, breast, prostate, pancreatic and ovarian. Both observational and experimental epidemiologic studies have reported that higher intakes of vitamin D are related to lower risk of cancer.