Vitamin D-related effects on gynecologic cancer diagnosis and prognosis trends: Ultraviolet radiation index associations in United States cancer registries

Objective: Vitamin D deficiency or excess has been implicated in the development and progression of various cancers. Seasonal trends in the diagnosis of cancer have been widely reported and have been hypothesized to relate to seasonal vitamin D synthesis changes. Ultraviolet radiation index (UVI), a meteorologic characteristic defining available ultraviolet radiation at a particular geographic location, is associated with variations in the physiologic production of vitamin D. This study examined the possibility of seasonal and geographic vitamin D-related effects in diagnosis and survival in gynecologic cancers. The seasonal diagnosis frequency as well as the 2-, 5-, and 10-year overall survival of patients with gynecologic cancer was compared by the UVI of the cancer registry of each patient.