Lung cancer is the leading cause of cancer-related deaths in Canada and the United States. It is an extremely lethal form of cancer, and approximately 85% of lung cancer patients will die within 5 years of their initial diagnosis. With such a dire prognosis, it makes sense to focus on lung cancer prevention and to do everything that you can to reduce your risk. Recent research suggests that vitamin D may do just that!
A study conducted at the University of California (U of C), San Diego, and published in the Journal of Epidemiology and Community Health, examined data across numerous continents and included 111 countries. According to this study, lung cancer rates are the highest in countries which are the furthest from the equator, where sunlight exposure, which is the primary source of vitamin D for humans, is quite low. In addition, countries with high cloud cover and high airborne aerosol levels also have a higher rate of lung cancer. Although smoking is still thought to be the strongest risk factor for cancer, the results of this study suggest that the vitamin D (in terms of UVB exposure) which is created by exposure to sunlight, also plays a prominent role.
All cancers begin when cells start to divide in an erratic and uncontrolled manner, which results in healthy cells turning into cancer cells. According to the lead researcher of the U of C study – Dr. Cedric Garland, vitamin D (in terms of UVB exposure) encourages the release of certain chemicals that form a glue-like substance that makes the cells stick together and thereby prevents them from dividing uncontrollably and turning into cancer cells.
Vitamin D has been found to not only reduce the risk for contracting lung cancer, according to a recent study conducted at the University of Michigan Comprehensive Cancer Center, it may also increase the survival rate in patients who have already been diagnosed with it. The researchers of this study found that levels of CYP24A1 (a naturally occurring enzyme) are up to 50 times higher in the lungs of lung cancer patients than they are in healthy lung tissue. The researchers also found that as CYP24A1 levels rose, so too did the lung cancer cells aggressiveness and the patients risk for fatality. What does this have to do with vitamin D you may ask? Well CYP24A1 breaks down the active form of vitamin D in the body.
Researchers are now working on developing a drug that prevents CYP24A1 levels from rising and/or reduces elevated CYP24A1 levels. This would be extremely beneficial because more than half of lung cancer patients who undergo surgery experience a return of the cancer.
These studies are just two of many that suggest vitamin D might play a role in reducing cancer risk, though it is not steadfast. The current daily recommendation for vitamin D is 600 to 800 IU daily; however some scientist and many Naturopathic Doctors believe that this number is far too low for cancer prevention. If you live in an area that does not get much sunlight talk to an alternative healthcare practitioner about an in ideal supplemental dose for your particular age, skin color and body size. If, on the other hand, you are lucky enough to live in an area with lots of sunlight, 15 minutes of daily sunlight exposure (without sunscreen) could possibly be enough to ensure adequate levels of vitamin D (and UVB exposure).