Ask most people what they fear most and the answer is almost always cancer. That’s because cancer rivals heart disease as our number one killer. We now have highly effective treatments for heart disease and even if someone experiences a heart attack, doctors can frequently intervene to save his life.
Cancer, on the other hand, is still mysterious. No one knows why one person can live a normal life after a cancer diagnosis while another person succumbs within a few years despite getting the same treatment.
Is Vitamin D Helpful for Cancer Prevention?
Preventing cancer and prolonging life after a diagnosis is the primary goal. Could vitamin D provide an important element in an anticancer strategy? There is growing evidence that the sunshine vitamin might play a far more important role in both cancer prevention and survival than most people realize.
What Does Sunlight Have to Do with Cancer?
Vitamin D is made by human skin when it is exposed to sunlight. Epidemiologists have known for a long time that people who live in areas where there is a lot of sunshine have a lower likelihood of coming down with cancer and people who live in areas of less sunshine have a higher likelihood of developing cancer (Cancer Causes & Control, March, 2005; Anticancer Research, Sept, 2009; Epidemiology and Genomics Research, National Cancer Institute, May 7-8, 2007; BJU International, Nov. 2011).
Evidence is growing that people with adequate vitamin D levels are less likely to be diagnosed with cancer and more likely to survive a cancer that occurs (Dermato-Endocrinology, Apr/May/June, 2012). Women with higher vitamin D levels had better survival after diagnosis with breast cancer (Carcinogenesis, online May 24, 2012).
A large study showed higher vitamin D levels associated with a lower likelihood of lethal prostate cancer (Journal of the National Cancer Institute, May 2, 2012). One protocol showed benefit for men with prostate cancer taking 4000 IU of vitamin D3 daily (Journal of Clinical Endocrinology and Metabolism, online Apr. 16, 2012). This dose is high, so no one should undertake such a dose without medical supervision!
More recent research is beginning to clarify how vitamin D fights cancer. It inhibits the stem cells that give rise to cancer and pushes cells to differentiate (Journal of Steroid Biochemistry and Molecular Biology, online Dec. 3, 2016). When cells differentiate, they are far less likely to become out-of-control tumor cells. In addition, the vitamin D receptor is crucial in preventing inflammatory bowel disease and colon cancer (Current Medicinal Chemistry, online Dec. 2, 2016).
Sunlight or Pills?
Which is better, sunlight or vitamin D3 pills? This is a highly controversial topic, and there isn’t good evidence currently available to answer this question. Some vitamin D experts believe that 10 to 15 minutes of sun exposure three or four times a week is the best solution to the vitamin D dilemma. Dermatologists, on the other hand, believe that going out in the sun without a high SPF sunscreen is just plain dangerous.
Dutch scientists have recently pointed out that sunlight may go beyond providing adequate vitamin D (Medical Hypotheses, Dec., 2016). In addition, sunlight affects our natural clocks (circadian rhythm), and through that has an impact on the immune system. They point out that in Europe people with intermittent sun exposure are more prone to the deadly skin cancer melanoma, while those with more regular exposure are at lower risk.
Symptoms of Vitamin D Deficiency
- Joint aches
- Mood swings
- Muscle pain
To read more about testing for vitamin D levels (and what is now considered prudent), the safest dosing range, preferable vitamin D formulations, and a variety of other practical you may wish to check out our Guide to Vitamin D Deficiency.
Meanwhile, make sure you are getting the right amount of sun or the optimal amount of vitamin D from a supplement. It just might save your life!