Vitamin D, also known as the “sunshine vitamin,” is produced through our body's natural response to sunlight exposure. Evidence has established a relationship between low vitamin D levels and higher mortality rates. A recent study conducted by researchers from the Dana-Farber Cancer Institute has revealed that vitamin D can lower a person’s risk for colorectal cancer by strengthening the immune system’s response to tumor cells.
"People with high levels of vitamin D in their bloodstream have a lower overall risk of developing colorectal cancer," lead researcher Dr. Shuji Ogino said in a statement. "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?"
Ogino and his colleagues gathered data from the Nurses’ Health Study and Health Professionals Follow-up Study, similar long-term health tracking studies that included 170,000 participants combined. From this data, researchers analyzed the records of 218 patients diagnosed with colorectal cancer and 624 cancer-free participants. Records included blood samples taken in the 1990s, which was before any participants developed cancer. These blood samples were tested for a substance produced by the liver in response to vitamin D, known as 25-hydroxyvitamin D.
Participants with higher amounts of 25-hydroxyvitamin D also had a lower risk of developing colorectal tumors that are infused with immune system cells. Colorectal tumors that bind with immune system cells are often resistant to the immune response. According to the National Institutes of Health, around 1,000 different genes that control every tissue in our body are regulated by vitamin D levels. A similar study conducted at the University of California, San Diego found that participants with lower levels of vitamin D were significantly more at risk to colorectal and breast cancer.
"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 added. "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."
Vitamin D is incessantly linked to multiple health benefits. While a healthy vitamin D supply is associated with a lower risk of chronic diseases, such as diabetes, multiple sclerosis, and certain types of cancer, it can also improve certain aspects of everyday life. For example, the proper amount of sunlight exposure can enhance our mood by increasing serotonin levels. It can also help us get a better night’s sleep by maintaining a normal circadian rhythm, which includes mental, physical, and behavioral changes after a 24-hour cycle.
Source: Song M, Nishihara R, Ogino S, et al. Plasma 25-hydroxyvitamin D and colorectal cancer risk according to tumour immunity status. Gut. 2015.