People having high levels of vitamin D in their bloodstream have a lower overall risk of developing colorectal cancer. Vitamin D can protect some people with colorectal cancer by perking up the immune system's vigilance against tumor cells, according to a new study by Dana-Farber Cancer Institute investigators.
Senior author of the study, Shuji Ogino, said, "Laboratory research suggests that vitamin D boosts immune system function by activating T cells that recognize and attack cancer cells. In this study, we wanted to determine if these two phenomena are related: Does vitamin D's role in the immune system account for the lower rates of colorectal cancer in people with high circulating levels of the vitamin?"
To determine if this is indeed the case, the research team analyzed data from 170,000 participants in the Nurses' Health Study and Health Professionals Follow-up Study. Researchers compared selected groups of 318 colorectal cancer patients and 624 individuals who were free of cancer. All 942 subjects had blood samples drawn in the 1990s, before any developed cancer. The investigators tested these samples for 25-hydroxyvitamin D, 25(OH)D, a substance produced in the liver from vitamin D. Researchers found that patients with high amounts of 25(OH)D indeed had a lower than average risk of developing colorectal tumors that were enriched with immune system cells.
Ogino said, "This is the first study to show evidence of the effect of vitamin D on anti-cancer immune function in actual patients, and vindicates basic laboratory discoveries that vitamin D can interact with the immune system to raise the body's defenses against cancer. In the future, we may be able to predict how increasing an individual's vitamin D intake and immune function can reduce his or her risk of colorectal cancer."
The research is published in the journal 'Gut'.