Can vitamin D fight colorectal cancer?
Dana-Farber Cancer Institute researchers say that vitamin D may help fight colorectal cancer by enhancing the patient’s immune system. “People with high levels of vitamin D in their bloodstream have a lower overall risk of developing colorectal cancer,” Dr. Shuji Ogino, author of the study published in Gut, 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?”
During the research, 942 individuals from the long running Nurses’ Health Study and the Health Professional Follow-up Study projects were divided in two different groups; there were 318 colorectal cancer patients in one group and 624 participants without cancer in the other. Blood samples all participants had provided in the 90’s – decades before developing cancer risks – were retested for a substance called 25-hydroxyvitamin D (25(OH)D) which the liver makes from vitamin D. Participants with high levels of this substance were found to be less likely to develop colorectal cancer, suggesting that this derivative of vitamin D has endowed their immune system cells with colorectal cancer immunity.
The CDC describes colorectal cancer as the 3rd most common cancer and the 4th global leading cancer death – and the 2nd leading cause of cancer death in the United States, where more than 50,000 people died of it in 2011 alone. Vitamin D can be obtained from direct exposure to sunlight. Since sunlight is a source of another cancer, people can safely ingest vitamin D in the form of food and drug supplements. Vitamin D is known to enhance the immune system and help with calcium absorption and bone formation and repair. Previous research has also linked it with a decreased risk of multiple sclerosis, heart attack, and asthma. However, “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,” Ogino said.”
In addition to that, “this is the largest study that has been undertaken of metastatic colorectal cancer patients and vitamin D. It’s further supportive of the potential benefits of maintaining sufficient levels of vitamin D in improving patient survival times,” medical oncologist Dr. Kimmie Ng, who led additional research at the Dana-Farber Institute said. Ng found that patients with metastatic colorectal cancer and high vitamin D levels before treatment outlived patients with lower vitamin D blood levels. “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,” Ogino added.