Researchers from the Dana-Farber Cancer Institute have found that vitamin D may be able to prevent colorectal cancer in some people by boosting immune system function against cells in tumors. This is the first time that the connection between the vitamin and body's immune system response against cancer was shown in a sizable human population.
Adding to the growing number of research highlighting vitamin D's role in preventing cancer, the study was carried following the theory that if generous levels of the vitamin means less overall risk for developing colorectal cancer, then an individual with a lot of the vitamin in their bloodstream would unlikely develop colorectal cancer permeated by a lot of immune system cells. Should colorectal tumors do develop even when high levels of vitamin D are present, this means that the tumors have more resistance to the immune-system response.
Working with data from 170,000 individuals, researchers used two long-term health-tracking research projects, the Health Professionals Follow-up Study and the Nurses' Health Study. Out of this population, 942 individuals were carefully chosen: 318 with colorectal cancer and 624 persons without. Blood samples were taken from all subjects and were tested for 25-hydroxyvitamin D, a liver-produced substance derived from vitamin D.
Results revealed that those with high levels of the vitamin D-derived substance truly had below-average risks of getting colorectal cancer with tumors teeming with cells from the immune system.
"This vindicates basic laboratory discoveries that vitamin D can interact with the immune system to raise the body's defenses against cancer," said Shuji Ogino, M.D., Ph.D., M.S., senior author for the study.
He added that it may be possible in the future to foretell how boosting vitamin D levels in the body, which leads to increased immune system function, will be able to reduce colorectal cancer risks.
Published in the journal Gut, the study received funding support from the Paula and Russell Agrusa Fund for Colorectal Cancer Research, the Entertainment Industry Foundation, the Bennett Family Fund, the Friends of Dana-Farber Cancer Institute and the National Institutes of Health.
Vitamin D is naturally produced in the body when the skin is exposed to the sun but it can also be acquired through several food sources like fatty fish and fish oils. To a lesser extent, certain mushrooms, egg yolks, cheese and beef liver may also be eaten to get a day's dose of the vitamin.