Do Vitamin D Supplements Reduce the Risk of Dying from Cancer?

Do Vitamin D Supplements Reduce the Risk of Dying from Cancer?

September 16, 2019 31 By Ewald Bahringer


it all started with this famous study published in 1980 Johns Hopkins researchers were trying to figure out why states like New Mexico and Arizona had only about half the colon cancer rates of states like New York New Hampshire and Vermont maybe it’s because they got so much Sun and so they proposed that maybe the sunshine environment vitamin D is a protective factor against colon cancer since then sun exposure has been associated with lower rates of 14 other types of cancer – vitamin D may also affect cancer survival higher blood levels of vitamin D were associated with lower mortality of patients with colorectal cancer how much lower like nearly half the mortality and the higher the D levels the lower the death rate appeared to fall this may explain why the survival rate from colon cancer may depend on part on the season of diagnosis the reason the risk of rapid death is lowest if you’re diagnosed in the fall after you’ve spent the summer building up your vitamin D stores but look there are other risk factors that could be seasonal – maybe people are taking advantage of the fall harvest and eating healthier maybe that’s why lower risk in the fall season or maybe there’s more drinking in the winter and in the summer running around outside not only you’re getting more Sun you’re running around outside getting more exercise which may itself be protective so these kind of studies just provide circumstantial evidence establishing a cause and effect relationship between colon cancer vitamin D deficiency using observational studies is challenging because of confounding factors like the exercise so-called lurking variables for example there may be a tight correlation between ice cream sales and drowning death but that doesn’t mean icecream causes drowning a more likely explanation is that there’s a lurking third variable like hot weather summertime that explains white drowning deaths are highest when ice cream consumption is highest it’s kind of a trivial example but this actually happened with hormone replacement therapy women taking drugs like premarin appeared to have 50% less risk of heart disease and so doctors prescribe it to women by the millions but if you dig a little deeper into the data yes women taking estrogen had 50% lowered risk of dying from heart disease but they also had a 50% lower risk of dying from accidents and homicide so it probably wasn’t the drug see the only way to know for sure is to put it to the test and a randomized clinical trial where you give half the women the drugs see what happens and a decade later they did and instead of having a 50% drop in risk within a year of being given the hormone pills heart attack and death rates shot up 50% in retrospect the lurking variable was likely socioeconomic class or poor women are less likely to be scribed be prescribed hormone replacement therapy and more likely to be murdered and die of heart disease because of the lurking variable a drug we now know to be dangerous had appeared protective besides lurking variables there’s also the possibility of reverse causation maybe low vitamin D levels didn’t worsen the cancer maybe the cancer worsened the vitamin D levels and this may be unlikely since tumors don’t appear to directly affect vitamin D levels but cancer treatment might even simple knee surgery can dramatically drop vitamin D levels within hours thought to be because of just the inflammatory insult of cutting into somebody so maybe that could help explain the link between lower D and lower survival and he if you got cancer maybe you’re spending less time running around at the beach so yes higher vitamin D levels are associated with improved survival in call rectal cancer and in breast cancer in fact about double the risk of breast cancer recurrence and death in women with the lowest vitamin D levels and vitamin D levels also associated with longer survival with ovarian cancer and other cancers like lymphoma but bottom line as we learned with hormone replacement is that you have to put it to the test but there weren’t a lot of randomized controlled trials on vitamin D supplements and cancer until now we now have a few randomized controlled trials and vitamin D supplements do indeed appear to reduce the risk of dying from cancer what dose the researchers suggest may be getting blood levels up to at least around 75 nanomoles per liter levels not reached by as many three-quarters of women with breast cancer or a striking 97% of colon cancer patients getting up to these kind of levels 75 or perhaps even better a hundred might require about two to four thousand international units of vitamin D a day levels of intake for which there appeared to be no credible evidence of harm regardless with the exact level is the findings of these kind of studies may have a profound influence on future cancer treatment you