Vitamin Information Center

By Jean Carper
Anti-Aging Expert, Best-Selling Author and USA Weekend Columnist
Vitamin D is the hottest nutrient in medical circles now. It has been credited with fighting everything from cancer to chronic pain. The latest news:

Cuts heart attacks. Men with low levels of vitamin D are about two times more apt to suffer a heart attack than men with sufficient D, Harvard researchers say. Their theory: Vitamin D lessens inflammation, high blood pressure and vascular calcification, all factors in cardiovascular disease.

Curbs cancer. A research team at the University of California-San Diego says that 2,000 IU of vitamin D daily could reduce breast cancer rates by half and slash the risk of colon cancer by two-thirds.

Prevents diabetes. Men with blood richest in vitamin D were 72% less apt to develop type 2 diabetes after age 40 than men with the least vitamin D, says a new Finnish study.

Boosts brain. Older people with depression or dementia may benefit from extra vitamin D, Dutch researchers say. Men and women over 65 with major or minor depression had 14% lower vitamin D levels than their non-depressed peers. And among Alzheimer’s patients, those with higher vitamin D levels scored better on tests of cognitive function.

RELATED PRODUCTS: Our Multi Nutrient Formula contain 1,000 IU of vitamin D. In 2007, we increased the amount in our formulas from 600 IU to 1,000 IU, in response to research indicating that the RDA for vitamin D is far too low for most adults.

Eric Madrid, MD
Physicians and scientists are starting to realize the numerous health benefits of sunshine exposure and vitamin D supplementation. Most doctors know severe vitamin D deficiency causes rickets. Since rickets is rarely seen today, it is incorrectly assumed that vitamin D deficiency is nonexistent.

Fallbrook and Temecula medical providers have diagnosed hundreds of patients with vitamin D deficiency, or about 90 percent of all patients tested. Nine out of 10 people reading this story likely suffer from vitamin D deficiency.

Why should you have your vitamin D level checked? Studies have shown that those with lower levels of vitamin D in their blood have a higher risk of developing breast cancer, ovarian cancer, colon cancer, prostate cancer, type 1 diabetes, multiple sclerosis and heart disease. One study showed greater than a 60-percent reduction in breast cancer in those with the highest levels of vitamin D in their blood.

In addition, senior citizens who have lower levels of vitamin D in their blood are at higher risk of falls, osteoporosis and bone fractures. Those who suffer from chronic pain and fibromyalgia also have lower levels of vitamin D.

Vitamin D levels are checked by a simple blood test. Treatment usually requires supplementation with vitamin D3 as opposed to the more commonly sold over the counter vitamin D.

Vitamin D is also made from moderate daily sun exposure to the arms and legs. Caution must be taken to prevent sun burning. Many sunscreens will block out UVB, which is the type of sunlight needed for skin to make vitamin D. Those with darker pigment are higher risk of deficiency, which may explain the higher incidence of diseases in certain ethnic populations.

To check your vitamin D level, contact your physician or call (951) 676-4193 for an appointment.

Eric Madrid MD is a family physician with Rancho Family Medical Group, which has offices in Fallbrook and Temecula. See www.ranchofamilymed.com.

Launched a decade ago, the federal program requiring folic acid to be added to widely consumed foods has been hailed as one of the great public-health success stories. Harnessing a seemingly harmless vitamin, it helped slash the number of babies born with spina bifida and other devastating “neural-tube” defects.

But scientists are beginning to debate whether Canadians’ growing consumption of the nutrient may also be taking a terrible, unplanned toll, triggering hundreds of extra cancers annually, even as it makes pregnancies safer.

One Canadian specialist says the federal government should now consider abandoning fortification altogether, and focus folic-acid efforts more narrowly on the young women who unquestionably benefit from the vitamin.

“It’s a double-edged sword,” said Young-In Kim, a gastroenterologist and folic-acid researcher at the University of Toronto.

“It was meant to prevent neural-tube defects, and it did a wonderful job. [But] for people with pre-cancerous cells, or undiagnosed colon cancer tumours, giving high-dose folic acid or having high folate levels might actually make their condition worse.”

Other experts, though, argue that fortifying food offers well-proven health advantages, while evidence of any cancer risk is inconclusive at best. In fact, the Society of Obstetricians and Gynecologists of Canada has advocated higher intake of folic acid supplements for some women, while the March of Dimes and American Medical Association in the United States have called for doubling the level of folic acid - or folate - that must be added to flours and other raw grains.

“You need more substance to show harm [from folate fortification], and there has been a clear absence of substance,” said Dr. Joel Ray, a scientist at St. Michael’s Hospital in Toronto who has studied folic acid. “We shouldn’t backtrack and change the direction of the program right now.”

Health Canada has reviewed what it calls the “inconsistent” evidence on the issue, and has no plans to alter or cancel the program, said Alastair Sinclair, a department spokesman.

“It is not possible to conclude that fortification has increased the rates of colorectal cancer incidence in Canada,” he said.

The folic-acid story revolves around birth defects, specifically those where the fetus’s neural tube, which becomes the brain and spinal cord, develops improperly, sometimes resulting in major disabilities. Folic acid seems to have a powerful preventive effect. A 2007 study concluded that rates of spina bifida and other neural-tube defects fell by about 50% - or about 110 babies a year - in the wake of the fortification program.

Adding the vitamin to food started on a voluntary basis in this country in 1996, and became mandatory for white flour, enriched pasta and cornmeal in late 1998. Evidence had shown that many women of child-bearing age did not heed expert advice to take folic acid pills, which have limited effect if started after a woman becomes pregnant.

The target was younger women, but the fortification program, following on the heels of one in the U.S., led to a doubling on average in the level of folic acid in all Canadians. Some experts suggest that is not a bad thing: There is evidence that it actually protects people against certain cancers.

Two hotly contested studies published last year, however, have fuelled concerns that elevated levels in North American bloodstreams may be having the opposite effect. A trial published in The New England Journal of Medicine had been designed to test whether folic acid prevented pre-cancerous colorectal polyps. In fact, it found that those subjects taking folate supplements were slightly more likely to have multiple polyps and to develop prostate cancer.

Animal studies, meanwhile, have suggested that the vitamin can prevent colorectal cancer in healthy individuals, but can also make it more likely that pre-cancerous polyps will convert into malignancies and that existing cancers will develop faster.

Then there is the history of folate. In the 1940s, physicians experimented with giving it to children suffering from leukemia, only to find that it accelerated the disease. That discovery led to the development of the first chemotherapy drugs - ones that actually countered the effects of natural folate, said Kim.

He was among the experts consulted by U.K. officials recently as they considered implementing fortification. The British decided last year to put the plan on hold.

Another 2007 study, meanwhile, noted that colorectal cancer rates rose suddenly in both Canada and the U.S. in the years after folic acid fortification started, and suggested there could be a link. The rates here climbed to almost five extra cases per 100,000 annually, before sliding back to a level that was still somewhat higher than before fortification.

That means that as many as 1,500 additional Canadians were diagnosed with colorectal cancer yearly after folate levels started to soar.

Dr. Joel Mason of Tufts University in Boston, who spearheaded the study, said there is not yet enough evidence to justify actually cancelling the fortification program, but called for more research on the possible cancer connection. He also suggests that anyone who is not a woman in her reproductive years think twice about taking folic acid supplements, which only add to the levels provided by fortification.

“We don’t know whether taking vitamin supplements and fortifying food [with folic acid] … actually accelerates cancer risk among susceptible people, but there is certainly a scientific basis for that possibility,” Mason said.

“We can’t afford to ignore it. It’s not a trivial phenomenon.”

Yet his and the New England Journal study have both come under stiff criticism.

British experts on spina- bifida argued in a letter to The Lancet last year that the trial published in the New England Journal showed no significant evidence that folate can be carcinogenic. And, like Ray, they said the increased cancer rates identified in Mason’s study were likely just a result of stepped-up screening for colorectal cancer.

In the meantime, a study published last month in the World Journal of Gastroenterology offered a much rosier view of the vitamin. It found that after three years, patients who took folic acid supplements actually had a third as many of the polyps that can lead to colorectal cancer as those taking a placebo.

Hardly a week goes by, it seems, without a press release regarding a new vitamin D study appearing in my email box.

For example:

“Men with Low Vitamin D May Have Increased Risk of Heart Attack”
“Study Links Vitamin D to Colon Cancer Survival”
“Vitamin D Inadequacy May Exacerbate Chronic Pain”
“Low Vitamin D Levels May Worsen Osteoarthritis of the Knee”
“Low Levels of Vitamin D Associated with Depression in Older Adults”
“Study Links Vitamin D, Type 1 Diabetes”
“Vitamin D Linked to Reduced Mortality Rate in Chronic Kidney Disease”

Then, last Friday, came the uber-vitamin D press release:

“Low Vitamin D Levels Pose Large Threat to Health”

That study, published this week in the Archives of Internal Medicine, found a 26 percent increase in risk of early death from any cause among people with inadequate levels of vitamin D.

What’s going on? Why this sudden (or so it seems) interest in the “sunshine vitamin”? (The nickname comes from the fact that the vitamin is produced in the skin from sunlight.) And what are health consumers – especially here in Minnesota, where the low angle of the winter sun makes it difficult to sustain adequate vitamin D levels – to make of it all?

Old interest, new connections
Despite the current flurry of studies, research into vitamin D’s multipronged impact on human health “is not all that new,” said Kurt Kennel, M.D., an assistant professor of medicine at the Mayo Clinic in Rochester. Scientists have known since the 1970s that vitamin D’s effect on the body went beyond regulating calcium and helping to build strong bones.

Much of the past research, however, was confined to the laboratory. In recent years, thanks to better ways of assaying (or measuring) vitamin D in the body, scientists have been able to give it a more clinical face, linking it to the risk of developing different diseases.

In addition, aging baby boomers have developed a deep and personal interest in the bone-weakening disease osteoporosis.

“That put vitamin D on the map,” said Kennel.

A misnomer
To understand vitamin D’s ubiquitous role in the body, we need to stop thinking of it as a traditional vitamin.

“If we named it today, we’d call it a hormone,” said Kennel.

Like insulin, adrenaline, estrogen and other hormones, vitamin D is produced by a body organ (in this case, the skin). It’s then carried through the body by a fluid (blood) to other organs and tissues (the heart, brain, breasts, kidneys, muscles, and so on). At each of these destinations, vitamin D adeptly attaches itself to receptors on the DNA of genes in the cells’ nuclei.

As we’re now learning, the resulting effects appear to be remarkably beneficial, possibly protecting against heart disease, kidney disease, diabetes, osteoporosis, multiple sclerosis, certain types of cancers (including breast, lung and colon) and other major illnesses and conditions.

The latest study
In the newly published study – considered the most compelling evidence of vitamin D’s overall health benefits to date – a team of John Hopkins researchers analyzed vitamin D levels in more than 13,000 men and women aged 20 and older who participated in a large ongoing health survey conducted by the Centers for Disease Control and Prevention. The data was collected between 1988 and 1994.

To ensure comparable results, vitamin D levels were surveyed during the summer among participants living in northern states and during the winter among those in southern states.

All participants were tracked until Dec. 31, 2000, by which time 1,806 had died. Those whose vitamin D levels had been the lowest (less than 17.8 nanograms per milliliter of blood) had a 26 percent increased rate of death from any cause compared to those with the highest vitamin D levels (above 50 nanograms per milliliter).

Cardiovascular disease seemed to be the major factor in these deaths, although the study wasn’t able to determine with scientific certainty a cause-effect relationship between low vitamin D levels and heart attacks and strokes.

“In the past few months, several other papers have confirmed that low vitamin D levels are associated with increased risk of heart attacks and strokes,” said Erin Michos, M.D., one of the study’s lead investigators.

In fact, earlier this year, Michos and her team showed an 80 percent increased risk of peripheral artery disease among people with vitamin D deficiency.

It may not be long before vitamin D deficiency is added to the long list of risk factors for heart disease, she said.

What’s a consumer to do?
Vitamin D deficiency is, by some accounts, reaching epidemic proportions. A review article published in The New England Journal of Medicine last year reported that up to 50 percent of children and adults in the United States have insufficient levels (less than 20 nanograms per milliliter).

“Vitamin D deficiency is getting a lot more common because we’re getting more obese and sedentary, and we’re spending less time in the sun,” said Michos.

People who are over the age of 50, who have dark skin, or who wear clothing that covers most of their skin are also at increased risk. (The last two reasons, said Kennel, are partly why Minnesota’s Somali immigrants have higher-than-average rates of vitamin D deficiency.)

Both Kennel and Michos recommend that people boost their vitamin D levels by eating salmon, mackerel and other fatty fish and fortified dairy products. (Years ago, vitamin D used to be added to beer, but, alas, no longer.) You can also take cod-liver oil (yes, just as your great-grandparents did) and/or vitamin supplements.

Federal guidelines currently recommend that adults get 200 to 600 international units (IU) of vitamin D daily. Those recommendations are currently under review, said Kennel, and will most likely be upped.

The National Osteoporosis Society already recommends 800 to 1,000 IU to people aged 50 and older. And the Canadian Cancer Society, citing Canada’s northern latitude, recommends that adults living there take 1,000 IU of vitamin D daily during fall and winter.

Currently, most experts put the safe upper limit of vitamin D from supplementary sources at 2,000 IU per day. But that number, too, may be increased.

Out in the noonday sun
The best way to get vitamin D, of course, is to spend time in the sun. In a single 10-minute midday outing, your skin will produce about 10,000 IU.

Fortunately, your skin won’t let you overdose on vitamin D from the sun. But spending unprotected time in the sun increases your risk of skin cancer, which has also reached epidemic proportions in the United States.

“Unfortunately, the time of the day the dermatologist wants you to be out – the morning and the evening – is the worst time for your body to make vitamin D,” said Kennel.

If you think you’re at increased risk for vitamin D deficiency, talk with your physician about having your blood levels of the vitamin checked. You’ll then have a better idea of whether you need supplements.

And remember: Although the recent findings about vitamin D are intriguing and promising, the benefits are not yet proven.

Studies of other nutrients and hormones – vitamin E, vitamin A, and estrogen, to name a few – were also found to benefit the heart in observational studies. But when it came time for the clinical trials, not only did they fail to prevent heart disease, they actually increased the risk.

Stay tuned.

ATLANTA, April 14 (UPI) — U.S. researchers say they are learning how vitamins and minerals can stimulate or prevent the development of colon cancer.

Emory University researchers in Atlanta find in a study of 92 patients that supplementing a diet with calcium and vitamin D appears to increase the levels of a protein call Bax — which controls programmed cell death — that may push pre-cancerous cells to self-destruct.

In another, 200-patient, case-control study, led by Dr. Robert Bostick of Emory University, high levels of calcium and vitamin D together are associated with increased levels of E-cadherin, which moderates colon cells’ movement and proliferation.

A third study on the same 200-patients shows high levels of iron in the diet are linked to low levels of APC, a protein whose absence in colon cancer cells leads to their runaway growth.

All three studies — scheduled to be presented at the American Association for Cancer Research meeting in San Diego — use colorectal biopsy samples and are part of a larger effort to identify a portfolio of measurements which taken together could predict the risk of colon cancer.

“We want to have the equivalent of measuring cholesterol or high blood pressure, but for colon cancer instead of heart disease,” Bostick says in a statement.

ATLANTA, April 14 (UPI) — U.S. researchers say they are learning how vitamins and minerals can stimulate or prevent the development of colon cancer.Emory University researchers in Atlanta find in a study of 92 patients that supplementing a diet with calcium and vitamin D appears to increase the levels of a protein call Bax — which controls programmed cell death — that may push pre-cancerous cells to self-destruct.

In another, 200-patient, case-control study, led by Dr. Robert Bostick of Emory University, high levels of calcium and vitamin D together are associated with increased levels of E-cadherin, which moderates colon cells’ movement and proliferation.

A third study on the same 200-patients shows high levels of iron in the diet are linked to low levels of APC, a protein whose absence in colon cancer cells leads to their runaway growth.

All three studies — scheduled to be presented at the American Association for Cancer Research meeting in San Diego — use colorectal biopsy samples and are part of a larger effort to identify a portfolio of measurements which taken together could predict the risk of colon cancer.

“We want to have the equivalent of measuring cholesterol or high blood pressure, but for colon cancer instead of heart disease,” Bostick says in a statement.

Researchers at Emory University are learning how vitamins and minerals in the diet can stimulate or prevent the appearance of colon cancer.

Emory investigators will present their findings on biological markers that could influence colon cancer risk in three abstracts at the American Association for Cancer Research meeting in San Diego.

In a clinical study of 92 patients, supplementing diet with calcium and vitamin D appeared to increase the levels of a protein called Bax that controls programmed cell death in the colon. More Bax might be pushing pre-cancerous cells into programmed cell death, says Emory researcher Veronika Fedirko, who will present her team’s results (abstract 464).

Previous studies have shown that calcium and vitamin D tend to reduce colon cancer risk.

“We were pleased that the effects of calcium and vitamin D were visible enough in this small study to be significant and reportable,” Fedirko says. “We will have to fully evaluate each marker’s strength as we accumulate more data.”

The studies of colorectal biopsy samples are part of a larger effort to identify a portfolio of measurements that together can gauge someone’s risk of getting colon cancer, says Roberd Bostick, MD, MPH, professor of epidemiology at Emory’s Rollins School of Public Health.

“We want to have the equivalent of measuring cholesterol or high blood pressure, but for colon cancer instead of heart disease,” Bostick says. “These measurements will describe the climate of risk in the colon rather than spotting individual tumors or cells that may become tumors.”

More about Bostick’s plans for developing non-invasive blood or urine tests for colon cancer risk is available in an Emory Health Sciences Magazine article: http://whsc.emory.edu/_pubs/hsc/winter08/pdf/hold_out_your_finger.pdf

Another abstract from Bostick and his colleagues (565) demonstrates in a 200-patient case-control study that high levels of calcium and vitamin D together are associated with increased levels of E-cadherin, which moderates colon cells’ movement and proliferation.

A third abstract on the same case-control study (5504) shows that high levels of iron in the diet are linked to low levels of APC, a protein whose absence in colon cancer cells leads to their runaway growth.

Bostick and his colleagues are participating in a ten-year multi-center study of the effects of increased vitamin D and calcium and biomarker-guided treatment of colon cancer recurrence. The study involves almost 2,500 people nationwide who have regular colonoscopies.

In recent years, as disappointing research cast a dark cloud over the hyped benefits of some vitamins and nutrients, vitamin D has been a ray of sunshine.

It’s partly because vitamin D is naturally produced in our skin when exposed to the sun’s ultraviolet rays.

But, it’s also because its reputation as a bone builder and disease fighter has been borne out by increasingly solid evidence.

“More studies are showing that vitamin D in the body is more diverse and more important than what we had thought,” says Cheryl Rock, a registered dietitian and professor of nutrition at the University of California San Diego Medical School. “We’ve known that it’s crucial for the absorption of calcium, but now we think it may relate to cancer because its biochemical activity is so diverse.”

In 2007, researchers from UCSD’s Moores Cancer Center found that people with high blood levels of vitamin D had half the risk of breast and colon cancer of those with low levels.

A review of dozens of studies and research in the American Journal of Public Health says that women with the lowest vitamin D levels are five times more likely to get breast cancer than those with the highest levels, and the vitamin slows the progression of the disease. Low levels of vitamin D also correlate with up to a 70 percent increase in the risk for prostate cancer and double the risk of colon cancer.

And in a Harvard School of Public Health study in 2006, researchers found that people who took in the highest amounts of vitamin D cut their risk of pancreatic cancer almost in half compared with those with the lowest intakes.

What’s the cancer link? Research has shown that vitamin D helps regulate cell growth, a fundamental biological process that goes haywire in cancer.

But it may be more than just cancer risk and bone health that benefit from increased vitamin D.

In a study published earlier this year, researchers at Harvard Medical School found a strong link between vitamin D deficiency and cardiovascular disease. Researchers followed more than 1,700 members of the Framingham Offspring Study (children or grandchildren of the original participants in the 1948 Framingham Heart Study) for more than five years. They found the rate of cardiovascular disease events such as heart attacks, strokes and heart failure were from 53 percent to 80 percent higher in people with low levels of vitamin D in their blood.

A study in the June 2007 edition of Archives of Internal Medicine found a “significantly higher” prevalence of hypertension, diabetes and high triglyceride levels in individuals with lower levels of vitamin D.

Scientists are not sure what mechanisms connect vitamin D with reduced risk of heart disease and diabetes, but some studies have shown that the vitamin can lower inflammation by increasing levels of anti-inflammatory messengers.

Researchers are careful to point out that this study does not prove that taking vitamin D supplements reduces heart attacks and strokes. That can only be done with a large clinical trial in which vitamin D is compared with a placebo.

A deficiency of the vitamin is also believed to weaken the immune system. Some research shows that increased vitamin D may also protect against multiple sclerosis and rheumatoid arthritis, in which the immune system attacks the body’s own healthy tissue.

Vitamin D functions a bit differently from other vitamins. The inactive form of vitamin D, made by our skin as a result of sun exposure or obtained from food, is like a reservoir of raw material stored in our livers, fat tissues, muscles and blood. When needed, it’s converted to an active form, actually a hormone, that tells various parts of the body what to do.

While much of the research presents a positive and hopeful picture of how the sunshine vitamin can benefit us, it only works if we get enough of it. And, according to some medical and nutrition experts, many of us don’t.

One-third to one-half of otherwise healthy, middle-aged to older adults have low levels of vitamin D in the United States, Harvard researchers say. A University of California San Diego study found that the average U.S. adult intake of vitamin D is only 230 international units (IU) daily. The government’s current recommendation for vitamin D is 200 IUs a day for people up to age 50, 400 IUs to age 70, and 600 IUs for people over 70.

Many experts say the government guidelines are too low, because we’re not getting enough of the vitamin from the sun or our food.

Although the conscientious use of sunscreen has successfully filtered out the harmful cancer-causing UV rays, it’s also reduced the amount of vitamin D we’d normally get from the sun. During winter when the sun is low and people are not outdoors as often, people’s vitamin D levels drop significantly.

The problem is particularly serious in colder parts of the world, in people with dark skin, the elderly and those who are diligent about avoiding sun exposure.

Some researchers say we need at least 800 to 1,000 units of vitamin D daily, probably taken in the form of a supplement, to reap the health benefits. The studies that showed a link between the vitamin and reduced cancer and cardiovascular disease risk used at least 1,000 units of vitamin D every day.

Not everyone agrees that the recommended dosage be increased. The American Cancer Society favors keeping the current recommendation of 200 to 600 IUs for now, cautioning that more than 2,000 units is viewed in the government nutritional guidelines as potentially dangerous.

“In excess, vitamin D can be very toxic,” says Rock, who admits that the recommendation may need to be increased to 800 units daily. “Taking 2,000 IUs is the highest dosage in which you don’t see adverse effects. Any more than that and all bets are off.”

Some medical/nutrition experts advocate going to the source for more vitamin D.

“Just 10 to 15 minutes of sun on your face, arms or back twice a week is enough to keep your blood levels of vitamin D up. As we get older, we make the conversion less efficiently, so as we age we may need to get a little more sun exposure, maybe 20 minutes instead of 15,” says Rock, who notes that people with dark skin don’t convert the sun to vitamin D as readily, so they may also need more sun time.

Researchers from UCSD point out that people living closer to the equator have lower incidences of some cancers, including colon, lung, breast, ovary and prostate.

“Just don’t get carried away,” Rock says, noting that prolonged sun exposure increases the risk of skin cancer significantly. “You don’t need to spend hours in the sun and look like Malibu Barbie to get enough vitamin D.”

Relying on food for an adequate supply of vitamin D isn’t as easy, because not that many foods contain the vitamin.

Oily fish like sardines, salmon, mackerel and tuna all have vitamin D. So does cod liver oil. And eggs have a little bit.

“The good news is that many more foods are fortified with vitamin D. Milk has been fortified with vitamin D by law (since the 1930s to prevent the bone-deforming disease rickets). Many cereals are fortified and so are some cheeses and margarines and orange juice,” Rock says.

It’s important to try to get the right kind of vitamin D.

The vitamin has two main forms, D-2 and D-3. Vitamin D-2 is from plant sources and is the type often contained in many multivitamins and fortified foods. Vitamin D-3 is from meat sources and is considered to be the more potent and accessible. It’s what we make when our skin is exposed to sunlight.

“D-2 is not as bio-available as D-3, and our body doesn’t absorb it as well. So, if you take 400 IUs of D-2, you might not be getting all 400 units,” says Linda Copp, a registered dietitian and instructor of nutrition at San Diego State University.

Word is getting out to the supplement and food industry that vitamin D-3, or cholecalciferol, is the preferred form, and more of them are starting to offer it in their products, noting it boldly on the label.

How do you know if you’re lacking in vitamin D? You probably don’t know for sure. But if you rarely get any time in the sun and don’t eat or drink foods containing or enriched with the vitamin, or if your skin color is dark, chances are you may not be getting enough.

However, instead of guessing and haphazardly increasing your vitamin D dosage, Rock suggests having a blood test, which usually runs $100 to $200.

“It’s possible to measure the amount of vitamin D you have in your blood. Your health insurance probably won’t pay for it, but it’s not that expensive. And if you’re really concerned, it probably is a good idea to ask your doctor about being tested,” Rock says.

Beth Wood contributed to this article.

It sounds too good to be true… a little inexpensive pill that could block the development of some cancers, strengthen bones, prevent multiple sclerosis and alleviate winter depression.

But it’s not science fiction. The “new aspirin” could be Vitamin D. Just as we discovered that aspirin can guard against heart disease, Vitamin D could become a useful weapon in the fight against MS, osteoporosis, mild depression and one of the most devastating diseases of our time – cancer.

“As time has gone by, Vitamin D has raised its head as a sort of ambrosia for cancers,” says Dr. Louise Parker, an epidemiologist and a world expert in the environmental exposures that can lead to cancer. Or, in the case of Vitamin D, the lack of exposure.

“One of the most important sources of Vitamin D is from the sun and through your skin,” says Dr. Parker.

“Many parts of Canada don’t get much sun in the winter. We’ve also been telling people to cover up and use sunscreen to prevent skin cancer. Sunscreen actually impairs your (skin’s ability) to make Vitamin D.”

So the Canadian Cancer Society recommends that during the winter, Canadians take at least 1,000 units a day of Vitamin D, dubbed “the sunshine vitamin.”

Dr. Parker says 1,000 units a day is well beyond what you can obtain from your diet. Vitamin D is a bit of a rare vitamin, appearing only in fatty fish, cod liver oil and egg yolks. Even if you were to sunbathe in southern climates, you would not take in 1,000 units.

“If you were to lie naked on a beach in the Bahamas, and I don’t recommend that because of skin cancer, you cannot get up to the equivalent of 1,000 units of Vitamin D a day,” says Dr. Parker.

She notes Vitamin D as a factor is turning up in study after study. It turns out people with lung and colon cancer are Vitamin D deficient. And it helps the body absorb calcium. In a study examining whether women who took Vitamin D had a lower risk of osteoporosis, it was found the women taking Vitamin D had stronger bones than those who did not take the vitamin. Years later, researchers went back to that study and found that the women who took Vitamin D also had fewer cancers.

But before Vitamin D becomes the “new aspirin,” more research needs to be carried out.

Vitamin D works in very complicated ways, she says. It changes the way cells work. In fact, there is medical speculation that it may block cancer cell proliferation or improve immune system functions. But its role is not fully understood.

Lifestyle also has to be part of the equation. Dr. Parker is looking at how obesity, which we know can cause cancer, and exercise, which we know prevents cancer, could interact with Vitamin D. “At the population level, I am trying to understand how all these things fit together,” says Dr. Parker. “It’s very complex.” Dr. Parker describes it as looking for a piece of a jigsaw puzzle. “We know some of the jigsaw pieces, but not all,” she says.

Meanwhile, there is very little evidence that taking Vitamin D can harm you. Perhaps in huge doses it could cause kidney stones, but that has not been proven.

“On the average, 1,000 units a day is safe and is probably effective in reducing the risk of colon cancer, and maybe other cancers as well,” says Dr. Parker.

So does she take Vitamin D and recommend it? Absolutely. “I take 1,000 units of Vitamin D – one day on and one day off,” she says.

Source:

Dalhousie University via (http://www.newswise.com)

Dalhousie University (2008, February 16). A Ray Of Sunshine In The Fight Against Cancer:

Research reports keep rolling in on the importance of vitamin D in our diet-beyond its familiar role in helping us to build strong bones. Here are some of the findings: Periodontal disease, in a dental study of 6,700 people from 13 to 90, the gums of patients with higher blood levels of vitamin D were 20 percent less likely to bleed. “The evidence on gingivitis and tooth loss suggests that vitamin D influences oral health by decreasing inflammation,” said Bess Dawson-Hughes, director of the Bone Metabolism Lab at the Human Nutrition Research Center on Aging at Tufts University.

Cancer. Studies by Reinhold Vieth at the University of Toronto have reported a substantial reduction in the rates of colon cancer as blood levels of vitamin D went up. Dr. Vieth suggests that vitamin D inhibits a mechanism by which cancer cells spread or it may boost the function of blood vessels or the immune system.

Diabetes. A number of studies have found that people with higher blood levels of vitamin D had a lower risk of diabetes than people with lower levels. Researchers have suggested that vitamin D seems to influence responsiveness to insulin.

Fitness. A study at the Wake Forest University School of Medicine found that people with low blood levels of vitamin D scored from 5 to 10 percent lower on tests measuring grip strength, balance and walking speed than those who had higher levels. Apparently vitamin D helps build and repair muscles as well as bones.

Longevity. People who take vitamin D supplements may also live longer, according to Sara Gandini, Ph.D., of the European Institute of Oncology in Italy, and Philippe Autier, M.D., of the International Agency for Research on Cancer in France. “The intake of ordinary doses of vitamin D supplements seems to be associated with decreases in total mortality rates,” they reported.

“The results are remarkable,” according to Edward Giovannucci, M.D., ScD., of the Harvard School of Public Health, in an editorial on vitamin D research in the Archives of Internal Medicine.

What to do. Adults should try to get 800 international units (IU) daily of vitamin D-or 1000 IUs a day if you are 70 or older. The average U.S. adult intake of vitamin D is 230 IUs daily, according to a study reported in the journal Nutrition Reviews. Vitamin D is available from sunlight, of course, and from foods such as fatty fish, eggs, fortified milk and fortified cereals as well as supplements.

-Sources: Bottom Line Health, CSPI Nutrition Action Letter, and Tufts University Health & Nutrition Letter