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

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 have 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 vitamin—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, too.

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 a 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, too. Maybe people are taking advantage of the fall harvest, and eating healthier. Maybe that’s why the lower risk in the fall season. Or, maybe there’s more drinking in the winter. And, in the summer, running around outside, not only are you getting more sun; you’re running around outside, getting more exercise—which may itself be protective.

So, these kinds of studies just provide circumstantial evidence. Establishing a cause-and-effect relationship between colon cancer and 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 deaths, but that doesn’t mean ice cream causes drowning. A more likely explanation is that there is a lurking third variable—like hot weather, summertime—that explains why drowning deaths are highest when ice cream consumption is highest.

That’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 prescribed it to women by the millions. But, if you dig a little deeper into the data, yes, women taking estrogen had 50% lower 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, in a randomized clinical trial, where you give half the women the drug, and 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. Poor women are less likely to 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. 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 hey, if you’ve 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 colorectal 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 maybe getting blood levels up to at least around 75 nanomoles per liter; levels not reached by as many as three-quarters of women with breast cancer, or a striking 97% of colon cancer patients.

Getting up to these kinds of levels, 75, or perhaps even better, 100, might require about 2,000 to 4,000 international units of vitamin D a day—levels of intake for which there appear to be no credible evidence of harm. Regardless of what the exact level is, the findings of these kinds of studies may have a profound influence on future cancer treatment.

Doctor’s Note

What about just getting sun, instead? Be sure to check out my recent six-part video series:

Better, of course, to prevent colon cancer in the first place. See, for example:

For more on that extraordinary story about Premarin and hormone replacement therapy, see How Did Doctors Not Know About the Risks of Hormone Therapy?

In health,
Michael Greger, M.D.

Michael Greger, M.D., is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United

How Much Vitamin D Should You Take?

Randomized, controlled clinical trials have found that vitamin D supplements extend one’s lifespan. What is the optimal dose? What blood level is associated with living longest? In my nine-part video series on vitamin D back in 2011, I noted that the relationship between vitamin D levels and mortality appeared to be a U-shaped curve—meaning low vitamin D levels were associated with increased mortality. But so were levels that were too high, with the apparent sweet spot around 75 or 80 nanomoles per liter [nmol/L], based on individual studies like this one.

Why might higher D levels be associated with higher risk? Well, this was a population study; so, you can’t be sure which came first. Maybe the vitamin D led to higher risk. Or maybe higher risk led to the vitamin D, meaning maybe those who weren’t doing as well were prescribed vitamin D. Maybe it’s because these were Scandinavian studies, where they tend to take a lot of cod liver oil as the vitamin D supplement, one spoonful of which could exceed the tolerable upper daily limit of intake for vitamin A—which could have negative consequences, even if you don’t inject it into your penis.

I was surprised to see cod liver oil listed among the long list of things men have tried to inject into themselves because they felt they were coming up short, though may have ended up shorter after all the reconstructive surgery.

Anyways, the U-shaped curve is old data. An updated meta-analysis has shown that as population vitamin D levels go up, mortality appears to go down, and stay down—which is good, because then we don’t have to test to see if we’re hitting just the right level.

Routine testing of vitamin D levels is not recommended. Why? Well, it costs money, and in most people, levels come right up to where you want them with sufficient sun, or supplementation. So, they figure what’s the point?

But also because the test is not very good—results can be all over the place. What happens when you send a single sample to a thousand different labs around the world? You maybe expect a little variation, but not this. Results from the same sample ranged anywhere from less than 20 to over 100. So, depending on what lab your doctor sent your blood sample to, the results could have placed you here, or here; so, not necessarily very helpful.

So, what’s a safe dose that will likely get us to the purported optimal level? 1,000 units a day should get most people up to the target 75 nmol/L (which is 30 ng/mL).

But by most people, they mean 50%. To get around 85% of the population up to 75 would require 2,000 a day. 2,000 international units a day would shift the curve from here to here. That way, we can take the average person into the desired range without fear of toxicity. You can take too much vitamin D, but you don’t tend to see problems until blood levels get up around 250, which would take consistent daily doses in excess of 10,000.

Note that if you’re overweight, you may want to take 3,000, or if obese, even more than that. If you’re over age 70, and not getting enough sun, it may take 3,500 units to get that same 85% chance of bumping your levels past the target. Again, no need for the average person to test and retest, since a few thousand a day should bring almost everyone up without risking toxicity.

Okay, but then why did the Institute of Medicine set the Recommended Daily Allowance at 600 to 800 units? In fact, official recommendations are all over the map—ranging from just 200 a day, all the way up to 10,000 a day. I’ll try to cut through the confusion, next.

In health,
Michael Greger, M.D.

Michael Greger, M.D., is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United

Optimal Dose Of Vitamin D For Breast Cancer Prevention Explained

If everyone took 2,000 units of vitamin D a day, it could shift the curve from average blood levels in the mid-50s to about 110 [nanomoles per liter], which some estimate could add years to our life expectancy. Data derived from randomized clinical trials have convinced some influential experts, such as Harvard’s Chair of Nutrition, that we should shoot for this kind of range—levels that about nine out of ten people fail to reach, because it may necessitate taking between 1,800 and 4,000 units a day.

The Institute of Medicine, however, considered blood levels of 50 to be sufficient, and, therefore, only recommended 600 to 800 units a day for those with little or no sun exposure, because they were only considering bone health. But even if you just cared about your bones, and not your lifespan, you’d still probably want to shoot for the 75 threshold, because there’s evidence like this— from hundreds of autopsies of people that like died in car accidents showing osteomalacia (softening of the bones) in between 18 and 39 percent of people that reach the Institute of Medicine target, but fail to make it to 75.

There’s even been a charge that the Institute of Medicine simply just made a mistake in their calculations, and, using their own criteria, they should be recommending thousands of units a day as well. But the mere absence of soft bones can hardly be considered an adequate definition either of health or of vitamin D sufficiency. It’s like saying you only need 10 milligrams of vitamin C to avoid scurvy—yeah, but we need way more than that for optimal health.

The Institute of Medicine took the position that the burden of proof fell on anyone who claimed benefits for intake higher than their minimal recommendations—which is a good approach for drugs. For unnatural substances, less is more, until proven otherwise. But for nutrients, shouldn’t the starting point, at least, be the natural levels to which our bodies have become finely tuned for millions of years?

The target level of 75 only sounds high compared to average levels today. But in modern times, we practice unnatural activities, like working at a desk job, or, sometimes, even wearing clothes. We evolved running around naked in equatorial Africa, getting sun all day long.

If you measure vitamin D levels in those living traditional lives in the cradle of humanity, a normal vitamin D level would be over 100. So, maybe that should be the starting point, until proven otherwise; a concept, regrettably, many guidelines committees seem to have ignored.

Now look, the natural level isn’t necessarily the optimal level. Maybe the body would have thrived with less. So, you still have to look at what levels correspond to the lowest disease rates. And when you do, the highest levels do indeed seem to correlate with less disease.

You know, it always struck me when I was doing pediatrics, that breastfed babies required vitamin D drops. I mean, shouldn’t human breast milk be a perfect food? Of course, for the medical profession, the solution is simple, right? Provide the baby supplements: the drops. But it seems like we shouldn’t have to. It should be perfect. But look, you measure human breast milk these days, and it has virtually no vitamin D, and would cause rickets, unless the mom has vitamin D levels up around, you guessed it, the level natural for our species, which, of course, makes total sense.

So, it’s just like an environmental mismatch, the way we live in our modern world. It helps to think of vitamin D as what is truly is—a hormone, not a vitamin. So, if you think of it like that, then it would be reasonable to have normal levels. We physicians try to maintain blood pressure, and all sorts of parameters, within normal limits, “but why is so little attention paid to the status of the hormone ‘vitamin D’?”

In health,
Michael Greger, M.D.

Michael Greger, M.D., is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United

The Latest on Vitamin D and Breast Cancer

Lastest Research on Vitamin D and Breast CancerBy: Rachel Pappas, Breast Cancer Survivor and Founder of www.1UpOnCancer.com.

The link between Vitamin D deficiency, breast cancer, and breast cancer recurrence is not new. But now Vitamin D has actually been shown to kill breast cancer cells.

I was so intrigued by what I read, I had to get on the phone with the clinical investigator myself, especially since I, and most of the women I know with breast cancer have a Vitamin D deficiency, and I hear it more and more.

JoEllen Welsh, PhD, a professor at GenNYsis Center for Excellence in Cancer Genomics in Albany, NY, has studied Vitamin D and breast cancer for 30 years, but for the first time, has incubated fresh human samples with Vitamin D. She took samples of early and late stage tumors, those with and without receptors for estrogen, progesterone, and HER2.

“Within days, half the cells shriveled and died in every tumor,” she said.

“Eighty percent of people have a vitamin D receptor, and if they have a tumor with this receptor it has potential to respond to Vitamin D, just as estrogen-positive breast cancer responds to tamoxifen,” says Welsh.

Vitamin D actually becomes a hormone in the body, meaning it is transmitted through the blood to any and or all tissue.

Five human samples were tested, reflecting the following types and stages of breast cancer:

  • Stage IIIC ER and PR Negative
  • Stage IIIA HER2 Negative
  • Stage I ER and HER2 Negative
  • Stage IIA ER PR and HER Positive
  • Stage IIIC Triple Negative

What next?

Currently Welsh is doing genetic engineering in mice to understand the mechanisms that trigger a response.

“For example, we need to look at what levels you need? Is there a difference in how it works on triple negative breast cancer? Does it work in the presence of tamoxifen? What if the tumor has a BRCA mutation? Answering these questions is how we can predict who is most likely to benefit from optimal Vitamin D status,” says Welsh.

Caution: If you have breast cancer, you shouldn’t take vitamin D in place of your treatment medications. Talk to your physician for more advice about taking supplements.

Founder of  1UpOnCancer.ComRachel Pappas is breast cancer survivor. She is the founder of www.1UpOnCancer.com. And the author of Hopping Roller Coasters, which tells the story of her and her daughter, both diagnosed with bipolar disorder.
 

 

Vitamin D And Cancer

Learn About Vitamin D and CancerBy: Rachel Pappas, Breast Cancer Survivor, Founder of www.1UpOnCancer.com and the Author of Hopping Roller Coasters.

If your Vitamin D level is at least 30 ng/ml at the time of your cancer diagnosis, you double your chance for long-term survival, according to a Canadian study, and other studies have similar findings.

But even if your blood level was lower, or you don’t know what it was when you first learned you had this illness, ensuring optimal Vitamin D moving forward will only help you;  it’s been shown to promote cancer cell death.

“If you have cancer, your Vitamin D should be at least 30 ng/ml, but I recommend no less than 60 to increase your chance for long-term survival,” said Cedric Garland, PhD, a professor at the University of  California School of Medicine, San Diego, and the first researcher to link Vitamin D and cancer. His studies date back to 1980.

Know that most of us are deficient unless we take Vitamin D supplements, so here are measures to take to ensure that your Vitamin D blood levels are where they should be …

How much Vitamin D should I take, and in what form?

Most people with cancer should take roughly 4,000 units daily for a healthy Vitamin D status, though this could vary, according to Cedric. He also emphasizes that if you get a prescription, to be sure it is NOT Vitamin D2, but Vitamin D3 (cholecalciferol).

“People should take only Vitamin D3 because we know that Vitamin D2 is a poor alternative. Experiments in animals and tissue cultures have found D2 is half to a third as effective in inhibiting cancer cell growth,” he said.

Which cancers does Vitamin D work against … and how?

Vitamin D has been shown to fight and help prevent cancer of the epithelial cells (these cells line organs), which includes over 90 percent of malignancies. The way it works, explained at the most basic level, is Vitamin D makes epithelial cells stick together.

“This is important because when these cells don’t stick together they are free agents and compete. When they compete, the ones reproducing the fastest take over. Cancer cells grow faster than healthy ones, so they dominate,” said Cedric. His research shows that epithelial cells have Vitamin D receptors, making them sensitive to this anti-cancer nutrient.

How often and when should I be tested?

Cedric recommends getting your Vitamin D tested every March, as your levels will likely be lower during and just after winter, since the sun is our greatest source of Vitamin D3, other than supplements. Ideally you should be checked again six months later.

Vitamin D during chemo

Some cancer researchers believe Vitamin D can work with chemo to improve the drug’s effectiveness.

“This vitamin enhances early cell death of cancer cells. And it helps prevent formation of arterioles and capillaries that feed tumors, so while we need more studies, I believe it enhances chemo,” said Cedric.

Two precautions

Know that pharmaceutical Vitamin D is often D2, so if you get a prescription ask your doctor for Vitamin D3. Or you can buy D3 over the counter and are likely to get a quality product at a health food store.

A second precaution: Do not assume if a blood test shows you have adequate Vitamin D that you do, at least not if you have been taking Vitamin D2. “The blood test just measures 25-hydroxy vitamin D, not specifically Vitamin D3, which is the good stuff,” said Cedric.

Vitamin D before cancer

Most people have cells en route to cancer, so everyone should pay attention to Vitamin D for risk reduction. The research showing its role in prevention is powerful.

“When Vitamin D blood levels are at 80 ng/ml, 80% of breast adenocarcinoma (cancer of the epithelium) can be eliminated. That figure is based on an extrapolation from several breast cancer studies,” said Cedric. It is equally effective at reducing colon cancer risk at 40-60 ng/ml and, again, we have seen that it works against other epithelial cell cancers.

Is there enough proof of Vitamin D’s cancer-fighting ability?

A majority of the studies are observational rather than randomized clinical trials. With randomized trials, one group would get Vitamin D and another would receive another agent or placebo; then the two groups would be compared.

But significantly lower cancer rates and better outcomes after diagnosis have been shown in studies many times over, simply by looking at patients’ Vitamin D levels and following them carefully.

“Scientists have measured Vitamin D at baseline and followed patients for 7-12 years. Those with at least 30 ng/ml had approximately 50-60%  the death rate,” said Cedric.

“We have enough solid evidence from observational studies, and from many of them; Vitamin D is very effective against cancer.  But always discuss Vitamin D with your physician. Aim for a consensus that includes your doctor,” said Cedric.

Links to studies on Vitamin D:

 What is the Dose Response Relationship Between Vitamin D and Cancer Risk?

Vitamin D Inhibits Genetic Behavior That Promotes Some Aggressive Breast Cancers

Prognostic Effects of Vitamin D in Early Breast Cancer

Serum 25-hydroxyvitamin D and colon cancer: eight-year prospective study

Vitamin D and Colorectal Cancer

Founder of  1UpOnCancer.ComRachel Pappas is breast cancer survivor. She is the founder of www.1UpOnCancer.com. And the author of Hopping Roller Coasters, which tells the story of her and her daughter, both diagnosed with bipolar disorder.
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