A new study confirms an association between increased vitamin D levels and decreased risk of colon cancer.
Previous studies have shown that colon cancer mortality rates are lower in regions with greater sun exposure, which leads to vitamin D synthesis in the skin.
Kana Wu, M.D., Ph.D., of the Harvard School of Public Health in Boston and colleagues measured the levels of vitamin D in the blood plasma of 372 colorectal cancer patients and 739 controls. They used data from the Health Professionals Follow-up Study and the Nurses? Health Study.
In the health professionals study, the researchers found an association between higher concentrations of vitamin D in patients? plasma and reduced risk of colon cancer and colorectal cancer, though the latter link was not statistically significant. When combining data from both studies, the association held up for both colon and colorectal cancer.
?In conclusion, our data provide additional support for an inverse association between vitamin D and colorectal and in particular colon cancer risk,? the authors write.