Vitamin D: A Defense Against Cancer?
People with the highest vitamin D intake had a 12% lower risk of colorectal cancer and people with the highest blood levels had a 33% lower risk
Studies suggest that globally people do not get enough vitamin D, and a lack of vitamin D may lead to serious health problems. Adding to evidence shown that getting plenty of vitamin D may help protect against chronic diseases such as cancer, a study in the Journal of Clinical Oncology affirms these findings, suggesting that higher blood levels of vitamin D may lower their risk of colorectal cancer by more than 30%.
Linking vitamin D to lower risk
In this analysis, researchers reviewed data from 17 studies that included more than 13,000 participants, and looked at how much vitamin D people consumed through diet and supplements and examined whether there is a link between vitamin D blood levels and the risk of colorectal cancer. Blood levels of vitamin D were determined by measuring 25-hydroxyvitamin D.
"Vitamin D deficiency is considered an important risk factor for many types of solid cancers, especially colorectal cancer," commented the study authors. "Among patients with colorectal cancer, the prevalence of vitamin D deficiency is much higher, approaching 90%, than among other patients. Several studies have demonstrated that vitamin D may decrease the risk of cancer through various mechanisms."
Keep in mind that since the studies reviewed in this report were observational, they do not prove cause and effect. But they suggest an interesting association, which should be explored further through randomized, controlled trials.
Take ActionHere are some action steps to take to both optimize vitamin D levels and help prevent colorectal cancer:
(J Clin Oncol 2011. 10.1200/JCO.2011.35.7566)
Jane Hart, MD, board-certified in internal medicine, serves in a variety of professional roles including consultant, journalist, and educator. Dr. Hart, a Clinical Instructor at Case Medical School in Cleveland, Ohio, writes extensively about health and wellness and a variety of other topics for nationally recognized organizations, websites, and print publications. Sought out for her expertise in the areas of integrative and preventive medicine, she is frequently quoted by national and local media. Dr. Hart is a professional lecturer for healthcare professionals, consumers, and youth and is a regular corporate speaker.