Vitamin D and Cancer - The Evidence is In

Is there really a positive link between Vitamin D and cancer?

Once only associated with strong bones and teeth, new scientific research is finding strong links between vitamin d and cancer... that is, Vitamin D can cut your risk of developing common cancers by as much as 50%.

Says Sara Hiom, head of health information at Cancer Research UK, “There is evidence to suggest that the vitamin (Vitamin D) plays a role in keeping cells healthy."

Researchers in the U.S. have found that the “natural” form of Vitamin D, D3 or cholecalciferol, can dramatically cut our chances of getting breast, ovarian, colon, and prostate cancers by up to 50%.

As a matter of fact, researchers are telling us that they have known about the link between Vitamin D and cancer for years. They tell us that they've known about the link between higher levels of vitamin d and a decreased risk of developing certain cancers for some time now.

Well my question to them is this… what has been taking you so long to tell us?

They say that up until just recently, they did not know the levels of Vitamin D necessary to provide this decreased risk.

Vitamin D and Cancer - How Much is Enough?

What current research is now finding is that the optimum amount of Vitamin D necessary to reduce your risk of developing these cancers is 1000 IU. This is two and a half times the Recommended Daily Allowance of 400 IU set forth by the Food and Nutrition Board of the Institute of Medicine here in the U.S.

Many experts now believe that the current RDA of 400 IU for an adult is too low and does nothing more than help ward off chronic bone diseases such as rickets and osteoporosis.

Recently, an article appearing in the American Journal of Public Health, after reviewing 63 independent studies, concluded that thousands of lives might be saved each year and thousands more cancers prevented by folks taking supplemental Vitamin D.

Professor Cedric Garland of the University of California in San Diego who led a major study on the relationship between Vitamin D and cancer risk said this, “A preponderance of evidence, from the best observational studies the medical world has to offer has led to the conclusion that public health action is needed."

This public health action he advocates is the education of the public concerning Vitamin D and cancer.

Vitamin D and Cancer - What form of Vitamin D is Best?

Remember that your body has the ability to manufacture its own Vitamin D through direct exposure to sunlight. This form of Vitamin D is called Vitamin D3 or cholecalciferol. This of course is the best form of the vitamin.

The synthetic form is Vitamin D2 or ergocalciferol. This is what is used to fortify milk for instance. It is estimated that it takes twice as much D2 to get the same benefit as Vitamin D3.

Vitamin D3 can also be found in oily fish such as salmon (3 ounces = 530 IU), sardines (3 ounces = 231 IU), and Mackerel (3 ounces = 214 IU).

Unfortunately not all of us can get the required amount of sunlight necessary to produce enough Vitamin D3.

Some of us have fair skin and need to use sunscreen when we venture outdoors. Some of us have dark skin and do not produce as much Vitamin D3 due to our skin pigment.

And of course, the cold parts of the year can keep most of us indoors or bundled up when we do head outside.

And also unless you eat lots of oily fish, you are not going to get your 1000 IU there either.

Professor Garland warned about the dangers of overexposure to the sun, “Dark-skinned people, however, may need more exposure to produce adequate amounts of vitamin D, and some fair-skinned people shouldn't try to get any vitamin D from the sun. The easiest and most reliable way of getting the appropriate amount (of Vitamin D) is from food and a daily supplement.”

This positive link between Vitamin D and cancer certainly is good news.

Below is are a couple of reprints from  articles discussing the relationship between increased levels of Vitamin D and a significant decrease in cancer risk:

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Reported June 12, 2007

Vitamin D: Magic Bullet Against Cancer?

(Ivanhoe Newswire) -- Could a simple vitamin be the answer to cancer prevention?

Researchers who compared a large group of women who took daily doses of vitamin D with women who didn’t take the supplement believe the answer may be yes.

Their study found women age 55 and older taking 1,100 international units (IU) of vitamin D per day -- well above the currently recommended daily amount of 400 IUs -- had a whopping 60-percent reduction in cancer risk. The study, which was conducted over a four-year period, showed even better results when only the final years worth of data were included.

Speculating some women entered the study with undiagnosed cancers, researchers analyzed cancer rates for just the last three years, discovering a 77-percent reduced risk among women taking vitamin D. The reduction in risk was seen across all major types of cancer, including cancers of the breast, colon, and lung.

The research was originally designed to look at the effects of calcium supplements on bone health in postmenopausal women, comparing women taking calcium alone, calcium plus vitamin D, or a placebo. Cancer risk was only a secondary measure, but is now taking center stage due to the stunning results.

“The findings are very exciting,” study author Joan Lappe, Ph.D., R.N., from Creighton University School of Medicine, was quoted as saying. “They confirm what a number of vitamin D proponents have suspected for some time but that, until now, have not been substantiated through clinical trial. Vitamin D is a critical tool in fighting cancer as well as many other diseases.”

The study was funded by the National Institutes of Health.

This article was reported by Ivanhoe.com, which offers Medical Alerts by e-mail every day of the week. To subscribe, click on: http://www.ivanhoe.com/newsalert/.

SOURCE: American Journal of Clinical Nutrition, published online June 7, 2007

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Vitamin D significantly reduces the risk of cancer
Medical Studies/Trials
Published: Monday, 11-Jun-2007
Print - Vitamin D significantly reduces the risk of cancer   
 

Scientists say most people in North America are not taking enough vitamin D, and that could increase their risk for developing cancer quite significantly.

In a study conducted by researchers at Creighton University School of Medicine, researchers followed 1,179 healthy, postmenopausal women from rural eastern Nebraska for a four-year period between 2000 and 2005.

The women were all 55 years or older and free of known cancers for at least 10 years prior to entering the Creighton study; they were randomly assigned to take daily dosages of 1,400-1,500 mg supplemental calcium, 1,400-1,500 mg supplemental calcium plus 1,100 IU of vitamin D3, or placebos.

The research team found that those taking calcium, as well as a quantity of vitamin D3, at nearly three times the U.S. government's Recommended Daily Amount (RDA) for middle-age adults, showed a 60 percent or greater reduction in cancer risk than women who did not get the vitamin.

Lead investigator Joan Lappe, Ph.D., R.N., Creighton professor of medicine says vitamin D is a critical tool in fighting cancer as well as many other diseases.

Dr. Lappe believes the findings confirm what many have suspected for some time and supports a growing body of evidence that a higher intake of vitamin D may be helpful in the prevention and treatment of cancer, high blood pressure, fibromyalgia, diabetes mellitus, multiple sclerosis, rheumatoid arthritis and other diseases.

As a rule people make their own vitamin D3 when they are exposed to sunlight and just 10-15 minutes a day in a bright summer sun creates large amounts of the vitamin.

The researchers found that over the course of four years, women in the calcium/vitamin D3 group experienced a 60 percent decrease in their cancer risk than the group taking placebos.

Working on the premise that some women entered the study with undiagnosed cancers, the researchers then eliminated the first-year results and looked at the last three years of the study and the results appeared even more dramatic with the calcium/vitamin D3 group showing a remarkable 77 percent cancer-risk reduction.

In the three-year analysis, there was no statistically significant difference in cancer incidence between participants taking placebos and those taking just calcium supplements.

Through the course of the study, 50 participants developed non skin cancers, including breast, colon, lung and other cancers.

Lappe says more research is needed to determine whether the research results apply to other populations, including men, women of all ages, and different ethnic groups as all the study participants were Caucasian.

Where you live in the world as well as your ancestry influences the body's ability to convert sunlight into vitamin D; dark skinned people have more difficulty making the vitamin and those living at latitudes north of the 37th parallel are unable to get their vitamin D naturally during the winter months because of the shortage of sunlight.

There is agreement amongst experts that doses of vitamin D need to be increased in some situations, but debate persists on the amount.

Supplements are available in two forms, vitamin D2 and vitamin D3 and the researchers recommend vitamin D3, because it is more active and thus more effective in humans.

The study has prompted the Canadian Cancer Society to advise all Canadian adults to take large doses of vitamin D during the sun-poor winter months, and says the elderly and those with dark skins should take the supplements year round.

The Canadian Cancer Society says the Canadian population is at greater risk because of its latitude.

The society recommends that adults take 1,000 international units of vitamin D a day during fall and winter, while the elderly, dark-skinned people, or those who don't go outside often, should consider supplements year round.

The National Institutes of Health funded the study and the results are published in the June 8 online edition of the American Journal of Clinical Nutrition.

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