The People's Perspective on Medicine

Will Vitamin D Help Prevent Cancer?

In Japan, people with higher levels of vitamin D are less likely to develop cancer. Research has not yet determined whether vitamin D supplements will help prevent cancer.

Is there a connection between vitamin D levels and cancer risk? Previous studies have shown that people with low levels of vitamin D appear more susceptible to cancers of the pancreas, colon, breast and prostate. (See below for a report on bladder cancer and vitamin D.)  Conversely, higher levels of vitamin D have been associated with a lower risk of several different cancers. Could vitamin D help prevent cancer?

Do Robust Vitamin D Levels Prevent Cancer?

Most of the previous epidemiological research has been done in the US or Europe. Japanese researchers recently confirmed that this link held up over a large, prospective epidemiological study (Budhathoki et al, BMJ, March 7, 2018).

Vitamin D and Cancer in Japan:

They recruited more than 33,000 middle-aged adults who provided blood samples and data about their diet and exercise patterns. Over the next 16 years, approximately 3,300 of these people developed cancer. When the investigators analyzed the data, they found that those participants with higher levels of vitamin D had a 20 percent lower likelihood of a cancer diagnosis. Liver cancer was almost 50 percent less likely among people with the highest levels of vitamin D in their bloodstream.

Previous Research on Vitamin D and Bladder Cancer:

British researchers reported in 2016 that low levels of vitamin D increase the likelihood of developing bladder cancer.

What Is the Evidence for a Link with Bladder Cancer?

The investigators reached this conclusion through a systematic review of seven studies. They also tested cells from the lining of the bladder and found that vitamin D activated an immune response. They inferred that adequate vitamin D would stimulate these cells to fight off cancer.

Inadequate Vitamin D:

In northern countries with little sunlight, people have trouble maintaining adequate vitamin D levels. That is because sun-exposed skin manufactures this crucial compound. Without sun, the chemical reaction does not happen.

Vitamin D in Great Britain:

The authors point out that one in five British adults are deficient in this nutrient and 60 percent have low blood levels. Even experts do not know whether supplementation can help prevent cancer.

This research was presented at the Society for Endocrinology Annual Meeting, Brighton, UK, November 8, 2016

Is Vitamin D Deficiency a Problem in the US?

Far more of the U.S. lies in southern latitudes where sun exposure is strong, at least during the summer. According to the CDC, around two-thirds of the US population have sufficient levels of vitamin D. That means, however, that nearly one in three Americans is at risk for insufficient or deficient vitamin D levels.

Other Health Problems Associated with Low Vitamin D Status:

Not only does this increase the chance of bladder cancer, it also makes middle-aged adults more susceptible to calcified coronary arteries (Journal of the American College of Nutrition, Sep-Oct., 2016). It may also contribute to inflammatory bowel disease (Current Medicinal Chemistry, Oct. 26, 2016). People with low vitamin D levels are also more vulnerable to gum disease (BMC Oral Health, Sep. 2, 2016). Erectile dysfunction is more common among men with vitamin D deficiency (Atherosclerosis, Sep., 2016).

We discuss this critical vitamin and how it affects our health in our Guide to Vitamin D Deficiency.

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About the Author
Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies. .
Vitamin D Deficiency

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The Peoples Pharmacy program is very usefull and beneficial to all who care about their health. Long live Joe and Terry Graedon.

I spend a lot of time in the sun during the summer – always in shorts and tee shirt. My vit D levels are chronically low, and I have to supplement, although this was never a problem in my younger years. I have never seen research to establish that our natural capacity to make vit D begins to fail as our bodies get older, but it seems to me that this is true. Think then of nursing home residents who really never get any sunshine. It has to be an element of their decline and increased incidence of pain.

It would personally be more educational and useful for me to know the actual ranges for what low levels and high levels of vitamin D are, that are too low and protective, respectively.

Thanks for this helpful information. What dosage of vitamin D3 is recommended to maintain a healthy level of vitamin D?

The Brigham & Women Hospital conducted a 5 years study on the effects of Vitamin D and Omega-3 fatty acids on cancer and heart disease. The study just ended in February. It involved 24,000 individuals across the US. I was one of them. It was a double-blind study in that you could be taking Vitamin D & Fish oil or a placebo of either or both. The findings are supposed to be ready some time later this year. I just found out I was taking a Vitamin D placebo but an actual active omega-e fatty acids (1 gram of fish oil).

I get small warts on my fingers in the winter. Taking a vitamin D supplement makes them go away every time.

Caution: too much Vitamin D supplementation can cause extreme dizziness, as it happened to my friend’s 10 year old daughter. Her doctor wasn’t aware of it, but I mentioned it and as soon as she discontinued use temporarily, the dizziness disappeared, and she subsequently went on a lower dosage. Otherwise, I think taking Vitamin D-3 is awesome!

Interesting, yet too much sun can yield to skin cancer.

Since Vit D us really a hormone and not a vitamin, how safe is this?!
Also one of the best ways to raise D levels is by increasing Magnesium RBC levels and one of the best ways to tankag levels is by taking hormone D!!!
Is low D rampant because our soils are severely Low in Magnesium??
Since D moves Calcium around, where does it go without adequate Magnesium to actually build bone?

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