Areas where people have lower ultraviolet B light exposure often report higher colorectal cancer rates, according to a study published July 5 in BMC Public Health.
Vitamin D has been seen as a potential protective factor in developing CRC, according to the study. Researchers conducted an ecological study, assessing UVB exposure and crude incidence rates of CRC for different age groups in 186 countries.
The study concluded: "The age-dependent inverse association between UVB exposure and incidence of colorectal cancer exhibits a greater effect size among older age groups in global analyses. Studying the effect of chronic vitamin D deficiency on colorectal cancer etiology will help in understanding the necessity for population-wide screening programs for vitamin D deficiency, especially in regions with inadequate UVB exposure."