Using newly available data on worldwide cancer incidence, researchers have shown a clear association between breast cancer and a deficiency in exposure to sunlight. About 1,150,000 cases and 410,000 deaths from breast cancer occur annually worldwide.
Sunlight exposure triggers the photosynthesis of vitamin D3 in the body.
This paper used worldwide data only recently available through a new tool called GLOBOCAN, a database of cancer incidence, mortality and prevalence for 175 countries. This is the fourth paper using this tool to show a strong association between vitamin D and cancer. Previous studies examined the incidence of kidney cancer, ovarian cancer, and endometrial cancer.