The Vitamin D Newsletter
Remarkable Paper in British Medical Journal
February 28, 2010
This is a periodic newsletter from the Vitamin D Council, a non-profit trying to end the epidemic of vitamin D deficiency. If you want to unsubscribe, go to the end of this newsletter. If you are not subscribed, you can do so on the Vitamin D Council's website.
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A few weeks ago, the British Medical Journal published a remarkable paper, remarkable that it studied more than 500,000 subjects, remarkable that it had 56 (fifty-six) authors, remarkable that it confirmed low vitamin D levels obtained in the past are a risk factor for developing colon cancer in the future. However, the most remarkable part of the paper is that the 46 scientists minimized the true significance of their own research. They found that vitamin A, even in relatively low amounts, appears to thwart vitamin D's association with reduced rates of colon cancer.
Jenab M et al. Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations: a nested case-control study. BMJ 2010;340:b5500
This is a prospective nested case-controlled study, which means it uses subject's vitamin D blood samples obtained and frozen in the past and then reviews their medical records into the future to see who gets colon cancer, comparing the study subjects to similar members of the group that did not get the illness. Dr. Mazda Jenab and his 45 colleagues from the International Agency for Research on Cancer confirmed that low vitamin D levels are a risk for colon cancer in a dose response manner; those with the highest levels were about twice as less likely to develop colon cancer compared to those with the highest levels.
However, hidden on page eight is one sentence and a small table, which shows that the benefits of vitamin D are almost entirely negated in those with the highest vitamin A intake. And the retinol intake did not have to be that high in these older adults to begin to negate vitamin D's effects, about 3,000 IU/day. Remember, young autistic children often take 3,500 IU of retinol a day in their powdered multivitamins, which doesn't count any additional vitamin A given in high single doses.
This is the largest study to date showing vitamin A blocks vitamin D's effect and explains some of the anomalies in other papers on vitamin D and cancer. For example, Dr. Rachael Stolzenberg-Solomon of the NIH conducted two similar studies on pancreatic cancer, with startling different results. Her first paper showed high vitamin D levels tripled the subsequent risk of pancreatic cancer, her second paper showed no effect. The difference, the first was conducted in a cod liver oil country, Finland, the second in the USA.
Stolzenberg-Solomon RZ et al. A prospective nested case-control study of vitamin D status and pancreatic cancer risk in male smokers. Cancer Res. 2006 Oct 15;66(20):10213-9.
Stolzenberg-Solomon RZ, et al. Serum vitamin D and risk of pancreatic cancer in the prostate, lung, colorectal, and ovarian screening trial. Cancer Res. 2009 Feb 15;69(4):1439-47.
Prostate cancer is another good example; ten similar studies have been conducted on vitamin D blood levels and the risk of subsequent prostate cancer. Dr. Lu Yin of the German Cancer Research Center reviewed them in detail. Eight of the studies found no relationship but two studies found a U shaped curve, that is, an increased risk of prostate cancer at both lower and higher vitamin D levels. You guessed it; both of these studies were from Nordic countries where cod liver oil consumption is rampant.
Yin L et al. Meta-analysis of longitudinal studies: Serum vitamin D and prostate cancer risk. Cancer Epidemiol. 2009 Dec;33(6):435-45.
So why is there no relationship between vitamin D levels and the future risk of prostate cancer? All the subjects had their vitamin D levels checked in the late 1980s or 1990s, well into the sun-scare but before the vitamin D revolution. So how did these older people get high levels of vitamin D back then? Multivitamins? No, they only contained a meaningless 400 IU. Vitamin D supplements? No, they were not widely available back then and only contained a meaningless 200 to 400 IU of vitamin D if available. Sunshine? Maybe, but I doubt it. Studies have shown that the elderly were the first to abide by sun-avoidance advice; anyway, the elderly lose the ability to make vitamin D from sunshine; it takes the elderly up to ten times more time in the sun that the young to make an equivalent amount of vitamin D.
However, the elderly of many countries, not just Nordic countries, were raised on cod liver oil and I suspect that a sizable number of Americans continue to take cod liver oil as they age. While cod liver oil from the 1980s and 90s had higher amounts of vitamin D than does modern cod liver oil, it still had toxic amounts of A. I suspect if authors of the above ten studies had controlled for cod liver oil intake, they would have found that high retinol intake was blocking the cancer-preventing effects of vitamin D.
I say this because one author has controlled for retinol intake and the pre-cancerous condition, colon adenomas. Dr. Kyungwon Oh, of the Korea Centers for Disease Control and Prevention, working with Harvard epidemiologists, found that high retinol intake completely thwarted the beneficial effects of vitamin D, stating, "a higher retinol intake, approximately > 4,800 IU/day, appears to counter the beneficial effect of vitamin D . . ." In other words, exactly what the British Medical Journal paper found with colon cancer.
Oh K et al. Calcium and vitamin D intakes in relation to risk of distal colorectal adenoma in women. Am J Epidemiol. 2007 May 15;165(10):1178-86.
Let"s look at Dr. Pamela Goodwin"s study from the University of Toronto that studied breast cancer survival. This a very different study as it looked at vitamin D levels obtained after the diagnosis of breast cancer and subsequent survival in 535 Toronto women between 1989 and 1996. Vitamin D levels ranged from 3 ng/ml to 70 ng/ml. The women with the lowest levels were about twice as likely to die and to suffer distant cancer recurrence compared those with the highest levels. Ten year survival was 85% for those in the upper one-third of vitamin D levels compared to 74% in the lower one-third. However, the data suggested a U shaped curve for the women with levels above 40 ng/ml, that is, a higher risk of dying, but it was not statistically significant.
Goodwin PJ et al. Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer. J Clin Oncol. 2009 Aug 10;27(23):3757-63.
Again, let"s ask where women would get levels above 40 ng/ml in Toronto between 1989 and 1996? Sunshine? We know the answer is no as the authors found no seasonal variation in 25(OH)D levels in the 535 women, even in the women with the highest levels. So where did blood levels of 40-70 ng/ml come from in the early 1990s? Vitamin D supplements were not widely available in the early 1990s, and only contained meaningless doses when available. As sunshine was ruled out, they could only have gotten it from cod liver oil. I have emailed Dr. Pamela Goodwin, lead author, asking how hard it would be to see if cod liver oil use was asked about in the dietary questionnaire and if she could control for cod liver oil intake. She did find retinol intake was associated with higher vitamin D levels but I am particularly interested in cod liver oil intake in women with vitamin D levels above 40 ng/ml.
It's not just in breast cancer that vitamin D levels appear to have a treatment effect; it's in lung, prostate and colon cancer as well. Again, these are studies of people diagnosed with cancer to see if high vitamin D levels at the time of diagnosis are associated with improved survival.; that is, do high vitamin D levels have a treatment effect? On average, those with the highest vitamin D levels at time of diagnosis lived 2 or 3 times longer. One has to ask how high vitamin D levels are associated with greatly improved survival once you get cancer but a higher risk of getting cancer in the first place. That requires some gymnastic thinking and acrobatic basic science.
Zhou W et al. Circulating 25-hydroxyvitamin D levels predict survival in early-stage non-small-cell lung cancer patients. J Clin Oncol. 2007 Feb 10;25(5):479-85.
Ng K et al. Clin Oncol. 2008 Jun 20;26(18):2984-91. Circulating 25-hydroxyvitamin D levels and survival in patients with colorectal cancer. J Clin Oncol. 2008 Jun 20;26(18):2984-91.
Tretli S et al. Association between serum 25(OH)D and death from prostate cancer. Br J Cancer. 2009 Feb 10;100(3):450-4.
Remember, studies of vitamin D levels and subsequent risk of cancer are only one type of epidemiological study. Studies of latitude and cancer are quite clear, the less sunshine the higher the cancer risk. Studies of dietary vitamin D intake and cancer are also mostly supportive but such studies are limited by the tiny doses people get in their diets.
So it is not just autistic children that are being harmed by vitamin A. Avoid cod liver oil like the poison it is and check your multivitamins. Life Extension Foundation just reformulated their multivitamin to contain only 500 IU of preformed retinol. And, I am happy to report that Purity Products, which markets my vitamin D, has no preformed retinol at all in any of their multivitamins, only beta carotene. Purity has also stopped selling cod liver oil. Now, if only Carlson, Solgar, Nature's Way, and other companies would stop selling cod liver oil and stop selling their concentrated vitamin A supplements to a country whose problem is widespread sub-clinical vitamin A toxicity, I'd be a happier agitator.
John Cannell, MD
Executive Director
Vitamin D Council
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Sunday, February 28, 2010
Wednesday, February 24, 2010
Health and Longevity - What Makes VIVIX Different - Look 25 years Younger and Live 25 Years Longer
THE VIVIX DIFFERENCE
After last week's expose on the supposed claims of acai and mangosteen many of you asked me about the Vivix difference.
Some of you went so far as to ask whether one couldn't say exactly the same things about Vivix that were said about the acai and mangosteen products.
In response to your many requests, let me talk about what makes Vivix so special.
Let me start with the top two ingredients in Vivix - the resveratrol which is found in red wine and ellagic acid which comes from muscadine grapes.
These aren't the only beneficial ingredients in Vivix, but if I talked about all of the ingredients this letter would be several pages long.
Resveratrol and ellagic acid are both members of a naturally occurring class of compounds called polyphenols.
Polyphenols are found in fruits, green tea, coffee, chocolate and many other foods. They are excellent anti-oxidants and have a number of potential health benefits.
So it is perhaps no surprise that almost any food containing polyphenols has been turned into a supplement by someone. And most of these companies have a long list of supposed health benefits for their products.
So what is the Vivix difference? What makes Vivix different from all of these other polyphenol products?
#1: There are over 3000 published scientific studies on the top two ingredients in Vivix (1800 on resveratrol and 1200 on ellagic acid) compared to a handful for the other products on the market.
#2: Resveratrol is the only polyphenol that has been shown to delay the aging process and lead to a longer, healthier life span. This has been demonstrated in every organism tested - from yeast to worms to fruit flies to mice.
The anti-aging benefits of resveratrol have nothing to do with it's anti-oxidant potential. It is because it binds to a protein that turns on the body's anti-aging genes.
That is why you shouldn't pay any attention to the hype about the anti-oxidant potential of the other polyphenol products on the market. There is no proven link between anti-oxidants and longevity!
Of course, anti-oxidants do play many useful roles in the body, but Vivix has a higher ORAC
score (the standard measure of anti-oxidant potential) than most of those other products anyway.
So to the extent that anti-oxidant potential is important Vivix trumps the other products.
#3: The polyphenols in Shaklee's patent-pending polyphenol blend have all been shown to activate the same anti-aging genes as resveratrol.
That is not true of the polyphenols found in many of the other products on the market.
#4: The polyphenols in Shaklee's polyphenol blend are ten times more effective than resveratrol alone at preventing the formation of advanced glycation end particles (AGE particles) - a key mechanism of cellular aging.
With most of the other products on the market you don't know whether they affect any of the key mechanisms of cellular aging - because the companies simply haven't tested for them.
Of course, all of the studies I have referred to so far were done in cell culture or with animals. Here is where the biggest Vivix difference comes in:
#5: The are over 12 published clinical studies with resveratrol alone.
Of course, it will never be possible to do a clinical study on longevity - humans simply live too long.
However, the clinical studies have shown exactly the same beneficial effects as the animal studies. This means that resveratrol has the same effect in humans that it has in animals.
For example, resveratrol has been shown to turn on the same anti-aging genes, decrease the same markers of inflammation and oxidative stress, decrease cholesterol and triglyceride levels, improve insulin sensitivity, decrease platelet aggregation and increase the elasticity of the aorta in both humans and mice.
This tells us that resveratrol works in exactly the same way in humans that it does in animals.
We simply don't know whether that is true for most of the other products in the marketplace.
#6: Shaklee has done a clinical study proving that Vivix is effective.
Shaklee released the preliminary results this past August and the complete results will be available as soon as the study has been published.
I discussed those results in a previous "Tips From The Professor" health letter.
The study breaks new ground in that it shows how Vivix can reverse some of the detrimental effects of a bad diet.
However, the bottom line is that this study showed that Vivix has the effect on anti-aging genes in the human body that would be expected from all of the previous animal and human studies on resveratrol and ellagic acid.
And, of course, the real significance of this finding is that is shows that the amount of resvertrol and other polyphenols in Vivix is appropriate and that the polyphenols are bioavailable (That means that they get into your bloodstream in sufficient quantities to have a beneficial effect on your health).
Hopefully, this will help you understand why Vivix is light years ahead of the competition.
To Your Health! Dr. Stephen G Chaney
Dr Chaney has been a Professor of Biochemistry & Biophysics in the Dept of Nutrition, UNC Chapel Hill for nearly three decades, teaching Medical Students & runs an active Cancer Research Program. Dr Chaney is published in 95 peer reviewed studies in respected medical journals.
For more information on Vivix or other of Dr Chaney’s newsletters, contact:
www.bestself.myshaklee.com 239/591-4565
Products in harmony with nature! Sam & Bunny Sewell
After last week's expose on the supposed claims of acai and mangosteen many of you asked me about the Vivix difference.
Some of you went so far as to ask whether one couldn't say exactly the same things about Vivix that were said about the acai and mangosteen products.
In response to your many requests, let me talk about what makes Vivix so special.
Let me start with the top two ingredients in Vivix - the resveratrol which is found in red wine and ellagic acid which comes from muscadine grapes.
These aren't the only beneficial ingredients in Vivix, but if I talked about all of the ingredients this letter would be several pages long.
Resveratrol and ellagic acid are both members of a naturally occurring class of compounds called polyphenols.
Polyphenols are found in fruits, green tea, coffee, chocolate and many other foods. They are excellent anti-oxidants and have a number of potential health benefits.
So it is perhaps no surprise that almost any food containing polyphenols has been turned into a supplement by someone. And most of these companies have a long list of supposed health benefits for their products.
So what is the Vivix difference? What makes Vivix different from all of these other polyphenol products?
#1: There are over 3000 published scientific studies on the top two ingredients in Vivix (1800 on resveratrol and 1200 on ellagic acid) compared to a handful for the other products on the market.
#2: Resveratrol is the only polyphenol that has been shown to delay the aging process and lead to a longer, healthier life span. This has been demonstrated in every organism tested - from yeast to worms to fruit flies to mice.
The anti-aging benefits of resveratrol have nothing to do with it's anti-oxidant potential. It is because it binds to a protein that turns on the body's anti-aging genes.
That is why you shouldn't pay any attention to the hype about the anti-oxidant potential of the other polyphenol products on the market. There is no proven link between anti-oxidants and longevity!
Of course, anti-oxidants do play many useful roles in the body, but Vivix has a higher ORAC
score (the standard measure of anti-oxidant potential) than most of those other products anyway.
So to the extent that anti-oxidant potential is important Vivix trumps the other products.
#3: The polyphenols in Shaklee's patent-pending polyphenol blend have all been shown to activate the same anti-aging genes as resveratrol.
That is not true of the polyphenols found in many of the other products on the market.
#4: The polyphenols in Shaklee's polyphenol blend are ten times more effective than resveratrol alone at preventing the formation of advanced glycation end particles (AGE particles) - a key mechanism of cellular aging.
With most of the other products on the market you don't know whether they affect any of the key mechanisms of cellular aging - because the companies simply haven't tested for them.
Of course, all of the studies I have referred to so far were done in cell culture or with animals. Here is where the biggest Vivix difference comes in:
#5: The are over 12 published clinical studies with resveratrol alone.
Of course, it will never be possible to do a clinical study on longevity - humans simply live too long.
However, the clinical studies have shown exactly the same beneficial effects as the animal studies. This means that resveratrol has the same effect in humans that it has in animals.
For example, resveratrol has been shown to turn on the same anti-aging genes, decrease the same markers of inflammation and oxidative stress, decrease cholesterol and triglyceride levels, improve insulin sensitivity, decrease platelet aggregation and increase the elasticity of the aorta in both humans and mice.
This tells us that resveratrol works in exactly the same way in humans that it does in animals.
We simply don't know whether that is true for most of the other products in the marketplace.
#6: Shaklee has done a clinical study proving that Vivix is effective.
Shaklee released the preliminary results this past August and the complete results will be available as soon as the study has been published.
I discussed those results in a previous "Tips From The Professor" health letter.
The study breaks new ground in that it shows how Vivix can reverse some of the detrimental effects of a bad diet.
However, the bottom line is that this study showed that Vivix has the effect on anti-aging genes in the human body that would be expected from all of the previous animal and human studies on resveratrol and ellagic acid.
And, of course, the real significance of this finding is that is shows that the amount of resvertrol and other polyphenols in Vivix is appropriate and that the polyphenols are bioavailable (That means that they get into your bloodstream in sufficient quantities to have a beneficial effect on your health).
Hopefully, this will help you understand why Vivix is light years ahead of the competition.
To Your Health! Dr. Stephen G Chaney
Dr Chaney has been a Professor of Biochemistry & Biophysics in the Dept of Nutrition, UNC Chapel Hill for nearly three decades, teaching Medical Students & runs an active Cancer Research Program. Dr Chaney is published in 95 peer reviewed studies in respected medical journals.
For more information on Vivix or other of Dr Chaney’s newsletters, contact:
www.bestself.myshaklee.com 239/591-4565
Products in harmony with nature! Sam & Bunny Sewell
Sunday, February 14, 2010
PSYCH: LOVE or love? - by Sam and Bunny Sewell
PSYCH: LOVE or love? - by Sam and Bunny Sewell
LOVE or love?by Sam and Bunny SewellEvery time we try to explain the two kinds of love to someone, they know very well what we are trying to say.
http://thesteadydrip.blogspot.com/2008/09/love-or-love-by-sam-and-bunny-sewell.html
LOVE or love?by Sam and Bunny SewellEvery time we try to explain the two kinds of love to someone, they know very well what we are trying to say.
http://thesteadydrip.blogspot.com/2008/09/love-or-love-by-sam-and-bunny-sewell.html
Facts on comparison of US - Canadian - and British Health Care Systems
Facts on comparison of US - Canadian - and British Health Care Systems
There is a bogus email going around claiming to be published by "Investor's Business Daily" that gives false information about how bad socialized medicine is in Britain and Canada. The real facts are bad enough; no need for invented statistics. Here is verified information:
http://thesteadydrip.blogspot.com/2009/12/facts-on-comparison-of-us-canadian-and.html
There is a bogus email going around claiming to be published by "Investor's Business Daily" that gives false information about how bad socialized medicine is in Britain and Canada. The real facts are bad enough; no need for invented statistics. Here is verified information:
http://thesteadydrip.blogspot.com/2009/12/facts-on-comparison-of-us-canadian-and.html
Friday, February 12, 2010
Continuous Chest Compression CPR - Mayo Clinic Presentation(Video)
This is an excellent video regarding an updated and more effective version of CPR that doesn't require blowing in someone's mouth. Pass it on.
Tuesday, February 2, 2010
Miracle of Vitamin D: Sound Science, or Hype?
The Miracle of Vitamin D: Sound Science, or Hype?
By TARA PARKER-POPE
Imagine a treatment that could build bones, strengthen the immune system and lower the risks of illnesses like diabetes, heart and kidney disease, high blood pressure and cancer.
Some research suggests that such a wonder treatment already exists. It’s vitamin D, a nutrient that the body makes from sunlight and that is also found in fish and fortified milk.
Yet despite the health potential of vitamin D, as many as half of all adults and children are said to have less than optimum levels and as many as 10 percent of children are highly deficient, according to a 2008 report in The American Journal of Clinical Nutrition.
As a result, doctors are increasingly testing their patients’ vitamin D levels and prescribing daily supplements to raise them. According to the lab company Quest Diagnostics, orders for vitamin D tests surged more than 50 percent in the fourth quarter of 2009, up from the same quarter a year earlier. And in 2008, consumers bought $235 million worth of vitamin D supplements, up from $40 million in 2001, according to Nutrition Business Journal.
But don’t start gobbling down vitamin D supplements just yet. The excitement about their health potential is still far ahead of the science.
Although numerous studies have been promising, there are scant data from randomized clinical trials. Little is known about what the ideal level of vitamin D really is, whether raising it can improve health, and what potential side effects are caused by high doses.
And since most of the data on vitamin D comes from observational research, it may be that high doses of the nutrient don’t really make people healthier, but that healthy people simply do the sorts of things that happen to raise vitamin D.
“Correlation does not necessarily mean a cause-and-effect relationship,” said Dr. JoAnn E. Manson, a Harvard professor who is chief of preventive medicine at Brigham and Women’s Hospital in Boston.
“People may have high vitamin D levels because they exercise a lot and are getting ultraviolet-light exposure from exercising outdoors,” Dr. Manson said. “Or they may have high vitamin D because they are health-conscious and take supplements. But they also have a healthy diet, don’t smoke and do a lot of the other things that keep you healthy.”
Dr. Manson is leading a major study over the next five years that should provide answers to these questions and more. The nationwide clinical trial is recruiting 20,000 older adults, including men 60 and older and women 65 and older, to study whether high doses of vitamin D and omega-3 fatty acids from fish-oil supplements will lower risk for heart disease and cancer. (Learn about taking part in the study at www.vitalstudy.org.)
Dr. Manson said fish-oil supplements were included in the study because they are another promising treatment that suffers from a dearth of clinical trial evidence. In addition, both vitamin D and fish oil are known to have an anti-inflammatory effect, but each works through a different pathway in the body, so there may be an added health benefit in combining them.
Study participants will be divided into four groups. One will take both vitamin D and fish oil pills. Two will take either a vitamin D or a fish-oil supplement and a placebo. The fourth will take two placebo pills.
Vitamin D is found throughout the body and acts as a signaling mechanism to turn cells on and off. Right now, the recommended dose from food and supplements is about 400 international units a day for most people, but most experts agree that is probably too low. The Institute of Medicine is reviewing guidelines for vitamin D and is expected to raise the recommended daily dose.
Study participants will take 2,000 I.U.’s of vitamin D3, believed to be the form most easily used by the body. The study will use one-gram supplements of omega-3 fish oil, about 5 to 10 times the average daily intake.
The vitamin D dose is far higher than what has been used in other studies. The well-known Women’s Health Initiative study, for instance, tracked women taking 400 units of vitamin D and 1,000 milligrams of calcium. The study found no overall benefit from the supplements, although women who consistently took their pills had a lower risk of hip fracture. Even so, many experts think 400 units is far too low for any additional health benefits.
Another study, of 1,200 women, looked at the effects of 1,500 milligrams of calcium and 1,000 units of vitamin D. Women who took both supplements showed a lower risk for breast cancer over the next four years, but the numbers of actual cases — seven breast cancers in the placebo group and four in the supplement group — were too small to draw meaningful conclusions.
Although consumers may be tempted to rush out and start taking 2,000 I.U.’s of vitamin D a day, doctors warn against it. Several recent studies of nutrients, including vitamins E and B, selenium and beta carotene, have proved disappointing — even suggesting that high doses do more harm than good, increasing risk for heart problems, diabetes and cancer, depending on the supplement.
Despite the promise of vitamin D in observational studies, research into other supplements shows it’s difficult to document a benefit in otherwise healthy people, and virtually impossible to predict potential harms, notes Dr. Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic. Dr. Klein recently worked as national coordinator for Select, a study of vitamin E and selenium for prostate cancer. The study seemed promising, but in the end it showed no benefit from the supplements and a potentially higher risk for diabetes in selenium users.
“My sentiment is that the lesson we have learned form large trials with other vitamin supplements, including Select, is that there is no proven health or preventative benefit for dietary supplements in nutritionally replete populations, which accounts for most of the people who enter this sort of clinical trial,” Dr. Klein said. “It makes more sense to me to study dietary supplements or vitamins in populations who are deficient.”
People most at risk for vitamin D deficiency are older, have diabetes or kidney disease, stay indoors or have darker skin. African-American teenagers are at particularly high risk, possibly because in addition to their dark skin, they are less likely at that age to drink milk or play outside.
The scientific community continues to debate the optimum level of vitamin D. In general, people are considered to be deficient if they have blood levels below 15 or 20 nanograms per milliliter. But many doctors now believe vitamin D levels should be above 30. The ideal level isn’t known, nor is it known at what point a person is getting too much vitamin D, which can lead to kidney stones, calcification in blood vessels and other problems.
People’s vitamin D levels are influenced by whether they have light or dark skin, where they live, how much time they spend outdoors and by fish and milk consumption. To raise vitamin D without supplements, a person could increase sun exposure for 10 to 15 minutes a day. Eating more fish can help — a 3.5-ounce serving of wild fresh salmon has 600 to 1,000 I.U.’s of vitamin D — but it would take a quart of milk a day to get the recommended dose of vitamin D.
“What we know is that there are a lot of people who are vitamin D deficient based on estimates from national surveys,” said Dr. Michal L. Melamed, assistant professor of medicine at Albert Einstein College of Medicine in the Bronx. “But we don’t know what happens when the curve shifts to the other end. There probably is a risk to having too much vitamin D in the system.”
By TARA PARKER-POPE
Stuart Bradford
Imagine a treatment that could build bones, strengthen the immune system and lower the risks of illnesses like diabetes, heart and kidney disease, high blood pressure and cancer.
Some research suggests that such a wonder treatment already exists. It’s vitamin D, a nutrient that the body makes from sunlight and that is also found in fish and fortified milk.
Yet despite the health potential of vitamin D, as many as half of all adults and children are said to have less than optimum levels and as many as 10 percent of children are highly deficient, according to a 2008 report in The American Journal of Clinical Nutrition.
As a result, doctors are increasingly testing their patients’ vitamin D levels and prescribing daily supplements to raise them. According to the lab company Quest Diagnostics, orders for vitamin D tests surged more than 50 percent in the fourth quarter of 2009, up from the same quarter a year earlier. And in 2008, consumers bought $235 million worth of vitamin D supplements, up from $40 million in 2001, according to Nutrition Business Journal.
But don’t start gobbling down vitamin D supplements just yet. The excitement about their health potential is still far ahead of the science.
Although numerous studies have been promising, there are scant data from randomized clinical trials. Little is known about what the ideal level of vitamin D really is, whether raising it can improve health, and what potential side effects are caused by high doses.
And since most of the data on vitamin D comes from observational research, it may be that high doses of the nutrient don’t really make people healthier, but that healthy people simply do the sorts of things that happen to raise vitamin D.
“Correlation does not necessarily mean a cause-and-effect relationship,” said Dr. JoAnn E. Manson, a Harvard professor who is chief of preventive medicine at Brigham and Women’s Hospital in Boston.
“People may have high vitamin D levels because they exercise a lot and are getting ultraviolet-light exposure from exercising outdoors,” Dr. Manson said. “Or they may have high vitamin D because they are health-conscious and take supplements. But they also have a healthy diet, don’t smoke and do a lot of the other things that keep you healthy.”
Dr. Manson is leading a major study over the next five years that should provide answers to these questions and more. The nationwide clinical trial is recruiting 20,000 older adults, including men 60 and older and women 65 and older, to study whether high doses of vitamin D and omega-3 fatty acids from fish-oil supplements will lower risk for heart disease and cancer. (Learn about taking part in the study at www.vitalstudy.org.)
Dr. Manson said fish-oil supplements were included in the study because they are another promising treatment that suffers from a dearth of clinical trial evidence. In addition, both vitamin D and fish oil are known to have an anti-inflammatory effect, but each works through a different pathway in the body, so there may be an added health benefit in combining them.
Study participants will be divided into four groups. One will take both vitamin D and fish oil pills. Two will take either a vitamin D or a fish-oil supplement and a placebo. The fourth will take two placebo pills.
Vitamin D is found throughout the body and acts as a signaling mechanism to turn cells on and off. Right now, the recommended dose from food and supplements is about 400 international units a day for most people, but most experts agree that is probably too low. The Institute of Medicine is reviewing guidelines for vitamin D and is expected to raise the recommended daily dose.
Study participants will take 2,000 I.U.’s of vitamin D3, believed to be the form most easily used by the body. The study will use one-gram supplements of omega-3 fish oil, about 5 to 10 times the average daily intake.
The vitamin D dose is far higher than what has been used in other studies. The well-known Women’s Health Initiative study, for instance, tracked women taking 400 units of vitamin D and 1,000 milligrams of calcium. The study found no overall benefit from the supplements, although women who consistently took their pills had a lower risk of hip fracture. Even so, many experts think 400 units is far too low for any additional health benefits.
Another study, of 1,200 women, looked at the effects of 1,500 milligrams of calcium and 1,000 units of vitamin D. Women who took both supplements showed a lower risk for breast cancer over the next four years, but the numbers of actual cases — seven breast cancers in the placebo group and four in the supplement group — were too small to draw meaningful conclusions.
Although consumers may be tempted to rush out and start taking 2,000 I.U.’s of vitamin D a day, doctors warn against it. Several recent studies of nutrients, including vitamins E and B, selenium and beta carotene, have proved disappointing — even suggesting that high doses do more harm than good, increasing risk for heart problems, diabetes and cancer, depending on the supplement.
Despite the promise of vitamin D in observational studies, research into other supplements shows it’s difficult to document a benefit in otherwise healthy people, and virtually impossible to predict potential harms, notes Dr. Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic. Dr. Klein recently worked as national coordinator for Select, a study of vitamin E and selenium for prostate cancer. The study seemed promising, but in the end it showed no benefit from the supplements and a potentially higher risk for diabetes in selenium users.
“My sentiment is that the lesson we have learned form large trials with other vitamin supplements, including Select, is that there is no proven health or preventative benefit for dietary supplements in nutritionally replete populations, which accounts for most of the people who enter this sort of clinical trial,” Dr. Klein said. “It makes more sense to me to study dietary supplements or vitamins in populations who are deficient.”
People most at risk for vitamin D deficiency are older, have diabetes or kidney disease, stay indoors or have darker skin. African-American teenagers are at particularly high risk, possibly because in addition to their dark skin, they are less likely at that age to drink milk or play outside.
The scientific community continues to debate the optimum level of vitamin D. In general, people are considered to be deficient if they have blood levels below 15 or 20 nanograms per milliliter. But many doctors now believe vitamin D levels should be above 30. The ideal level isn’t known, nor is it known at what point a person is getting too much vitamin D, which can lead to kidney stones, calcification in blood vessels and other problems.
People’s vitamin D levels are influenced by whether they have light or dark skin, where they live, how much time they spend outdoors and by fish and milk consumption. To raise vitamin D without supplements, a person could increase sun exposure for 10 to 15 minutes a day. Eating more fish can help — a 3.5-ounce serving of wild fresh salmon has 600 to 1,000 I.U.’s of vitamin D — but it would take a quart of milk a day to get the recommended dose of vitamin D.
“What we know is that there are a lot of people who are vitamin D deficient based on estimates from national surveys,” said Dr. Michal L. Melamed, assistant professor of medicine at Albert Einstein College of Medicine in the Bronx. “But we don’t know what happens when the curve shifts to the other end. There probably is a risk to having too much vitamin D in the system.”
By TARA PARKER-POPE
Imagine a treatment that could build bones, strengthen the immune system and lower the risks of illnesses like diabetes, heart and kidney disease, high blood pressure and cancer.
Some research suggests that such a wonder treatment already exists. It’s vitamin D, a nutrient that the body makes from sunlight and that is also found in fish and fortified milk.
Yet despite the health potential of vitamin D, as many as half of all adults and children are said to have less than optimum levels and as many as 10 percent of children are highly deficient, according to a 2008 report in The American Journal of Clinical Nutrition.
As a result, doctors are increasingly testing their patients’ vitamin D levels and prescribing daily supplements to raise them. According to the lab company Quest Diagnostics, orders for vitamin D tests surged more than 50 percent in the fourth quarter of 2009, up from the same quarter a year earlier. And in 2008, consumers bought $235 million worth of vitamin D supplements, up from $40 million in 2001, according to Nutrition Business Journal.
But don’t start gobbling down vitamin D supplements just yet. The excitement about their health potential is still far ahead of the science.
Although numerous studies have been promising, there are scant data from randomized clinical trials. Little is known about what the ideal level of vitamin D really is, whether raising it can improve health, and what potential side effects are caused by high doses.
And since most of the data on vitamin D comes from observational research, it may be that high doses of the nutrient don’t really make people healthier, but that healthy people simply do the sorts of things that happen to raise vitamin D.
“Correlation does not necessarily mean a cause-and-effect relationship,” said Dr. JoAnn E. Manson, a Harvard professor who is chief of preventive medicine at Brigham and Women’s Hospital in Boston.
“People may have high vitamin D levels because they exercise a lot and are getting ultraviolet-light exposure from exercising outdoors,” Dr. Manson said. “Or they may have high vitamin D because they are health-conscious and take supplements. But they also have a healthy diet, don’t smoke and do a lot of the other things that keep you healthy.”
Dr. Manson is leading a major study over the next five years that should provide answers to these questions and more. The nationwide clinical trial is recruiting 20,000 older adults, including men 60 and older and women 65 and older, to study whether high doses of vitamin D and omega-3 fatty acids from fish-oil supplements will lower risk for heart disease and cancer. (Learn about taking part in the study at www.vitalstudy.org.)
Dr. Manson said fish-oil supplements were included in the study because they are another promising treatment that suffers from a dearth of clinical trial evidence. In addition, both vitamin D and fish oil are known to have an anti-inflammatory effect, but each works through a different pathway in the body, so there may be an added health benefit in combining them.
Study participants will be divided into four groups. One will take both vitamin D and fish oil pills. Two will take either a vitamin D or a fish-oil supplement and a placebo. The fourth will take two placebo pills.
Vitamin D is found throughout the body and acts as a signaling mechanism to turn cells on and off. Right now, the recommended dose from food and supplements is about 400 international units a day for most people, but most experts agree that is probably too low. The Institute of Medicine is reviewing guidelines for vitamin D and is expected to raise the recommended daily dose.
Study participants will take 2,000 I.U.’s of vitamin D3, believed to be the form most easily used by the body. The study will use one-gram supplements of omega-3 fish oil, about 5 to 10 times the average daily intake.
The vitamin D dose is far higher than what has been used in other studies. The well-known Women’s Health Initiative study, for instance, tracked women taking 400 units of vitamin D and 1,000 milligrams of calcium. The study found no overall benefit from the supplements, although women who consistently took their pills had a lower risk of hip fracture. Even so, many experts think 400 units is far too low for any additional health benefits.
Another study, of 1,200 women, looked at the effects of 1,500 milligrams of calcium and 1,000 units of vitamin D. Women who took both supplements showed a lower risk for breast cancer over the next four years, but the numbers of actual cases — seven breast cancers in the placebo group and four in the supplement group — were too small to draw meaningful conclusions.
Although consumers may be tempted to rush out and start taking 2,000 I.U.’s of vitamin D a day, doctors warn against it. Several recent studies of nutrients, including vitamins E and B, selenium and beta carotene, have proved disappointing — even suggesting that high doses do more harm than good, increasing risk for heart problems, diabetes and cancer, depending on the supplement.
Despite the promise of vitamin D in observational studies, research into other supplements shows it’s difficult to document a benefit in otherwise healthy people, and virtually impossible to predict potential harms, notes Dr. Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic. Dr. Klein recently worked as national coordinator for Select, a study of vitamin E and selenium for prostate cancer. The study seemed promising, but in the end it showed no benefit from the supplements and a potentially higher risk for diabetes in selenium users.
“My sentiment is that the lesson we have learned form large trials with other vitamin supplements, including Select, is that there is no proven health or preventative benefit for dietary supplements in nutritionally replete populations, which accounts for most of the people who enter this sort of clinical trial,” Dr. Klein said. “It makes more sense to me to study dietary supplements or vitamins in populations who are deficient.”
People most at risk for vitamin D deficiency are older, have diabetes or kidney disease, stay indoors or have darker skin. African-American teenagers are at particularly high risk, possibly because in addition to their dark skin, they are less likely at that age to drink milk or play outside.
The scientific community continues to debate the optimum level of vitamin D. In general, people are considered to be deficient if they have blood levels below 15 or 20 nanograms per milliliter. But many doctors now believe vitamin D levels should be above 30. The ideal level isn’t known, nor is it known at what point a person is getting too much vitamin D, which can lead to kidney stones, calcification in blood vessels and other problems.
People’s vitamin D levels are influenced by whether they have light or dark skin, where they live, how much time they spend outdoors and by fish and milk consumption. To raise vitamin D without supplements, a person could increase sun exposure for 10 to 15 minutes a day. Eating more fish can help — a 3.5-ounce serving of wild fresh salmon has 600 to 1,000 I.U.’s of vitamin D — but it would take a quart of milk a day to get the recommended dose of vitamin D.
“What we know is that there are a lot of people who are vitamin D deficient based on estimates from national surveys,” said Dr. Michal L. Melamed, assistant professor of medicine at Albert Einstein College of Medicine in the Bronx. “But we don’t know what happens when the curve shifts to the other end. There probably is a risk to having too much vitamin D in the system.”
By TARA PARKER-POPE
Stuart Bradford
Imagine a treatment that could build bones, strengthen the immune system and lower the risks of illnesses like diabetes, heart and kidney disease, high blood pressure and cancer.
Some research suggests that such a wonder treatment already exists. It’s vitamin D, a nutrient that the body makes from sunlight and that is also found in fish and fortified milk.
Yet despite the health potential of vitamin D, as many as half of all adults and children are said to have less than optimum levels and as many as 10 percent of children are highly deficient, according to a 2008 report in The American Journal of Clinical Nutrition.
As a result, doctors are increasingly testing their patients’ vitamin D levels and prescribing daily supplements to raise them. According to the lab company Quest Diagnostics, orders for vitamin D tests surged more than 50 percent in the fourth quarter of 2009, up from the same quarter a year earlier. And in 2008, consumers bought $235 million worth of vitamin D supplements, up from $40 million in 2001, according to Nutrition Business Journal.
But don’t start gobbling down vitamin D supplements just yet. The excitement about their health potential is still far ahead of the science.
Although numerous studies have been promising, there are scant data from randomized clinical trials. Little is known about what the ideal level of vitamin D really is, whether raising it can improve health, and what potential side effects are caused by high doses.
And since most of the data on vitamin D comes from observational research, it may be that high doses of the nutrient don’t really make people healthier, but that healthy people simply do the sorts of things that happen to raise vitamin D.
“Correlation does not necessarily mean a cause-and-effect relationship,” said Dr. JoAnn E. Manson, a Harvard professor who is chief of preventive medicine at Brigham and Women’s Hospital in Boston.
“People may have high vitamin D levels because they exercise a lot and are getting ultraviolet-light exposure from exercising outdoors,” Dr. Manson said. “Or they may have high vitamin D because they are health-conscious and take supplements. But they also have a healthy diet, don’t smoke and do a lot of the other things that keep you healthy.”
Dr. Manson is leading a major study over the next five years that should provide answers to these questions and more. The nationwide clinical trial is recruiting 20,000 older adults, including men 60 and older and women 65 and older, to study whether high doses of vitamin D and omega-3 fatty acids from fish-oil supplements will lower risk for heart disease and cancer. (Learn about taking part in the study at www.vitalstudy.org.)
Dr. Manson said fish-oil supplements were included in the study because they are another promising treatment that suffers from a dearth of clinical trial evidence. In addition, both vitamin D and fish oil are known to have an anti-inflammatory effect, but each works through a different pathway in the body, so there may be an added health benefit in combining them.
Study participants will be divided into four groups. One will take both vitamin D and fish oil pills. Two will take either a vitamin D or a fish-oil supplement and a placebo. The fourth will take two placebo pills.
Vitamin D is found throughout the body and acts as a signaling mechanism to turn cells on and off. Right now, the recommended dose from food and supplements is about 400 international units a day for most people, but most experts agree that is probably too low. The Institute of Medicine is reviewing guidelines for vitamin D and is expected to raise the recommended daily dose.
Study participants will take 2,000 I.U.’s of vitamin D3, believed to be the form most easily used by the body. The study will use one-gram supplements of omega-3 fish oil, about 5 to 10 times the average daily intake.
The vitamin D dose is far higher than what has been used in other studies. The well-known Women’s Health Initiative study, for instance, tracked women taking 400 units of vitamin D and 1,000 milligrams of calcium. The study found no overall benefit from the supplements, although women who consistently took their pills had a lower risk of hip fracture. Even so, many experts think 400 units is far too low for any additional health benefits.
Another study, of 1,200 women, looked at the effects of 1,500 milligrams of calcium and 1,000 units of vitamin D. Women who took both supplements showed a lower risk for breast cancer over the next four years, but the numbers of actual cases — seven breast cancers in the placebo group and four in the supplement group — were too small to draw meaningful conclusions.
Although consumers may be tempted to rush out and start taking 2,000 I.U.’s of vitamin D a day, doctors warn against it. Several recent studies of nutrients, including vitamins E and B, selenium and beta carotene, have proved disappointing — even suggesting that high doses do more harm than good, increasing risk for heart problems, diabetes and cancer, depending on the supplement.
Despite the promise of vitamin D in observational studies, research into other supplements shows it’s difficult to document a benefit in otherwise healthy people, and virtually impossible to predict potential harms, notes Dr. Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic. Dr. Klein recently worked as national coordinator for Select, a study of vitamin E and selenium for prostate cancer. The study seemed promising, but in the end it showed no benefit from the supplements and a potentially higher risk for diabetes in selenium users.
“My sentiment is that the lesson we have learned form large trials with other vitamin supplements, including Select, is that there is no proven health or preventative benefit for dietary supplements in nutritionally replete populations, which accounts for most of the people who enter this sort of clinical trial,” Dr. Klein said. “It makes more sense to me to study dietary supplements or vitamins in populations who are deficient.”
People most at risk for vitamin D deficiency are older, have diabetes or kidney disease, stay indoors or have darker skin. African-American teenagers are at particularly high risk, possibly because in addition to their dark skin, they are less likely at that age to drink milk or play outside.
The scientific community continues to debate the optimum level of vitamin D. In general, people are considered to be deficient if they have blood levels below 15 or 20 nanograms per milliliter. But many doctors now believe vitamin D levels should be above 30. The ideal level isn’t known, nor is it known at what point a person is getting too much vitamin D, which can lead to kidney stones, calcification in blood vessels and other problems.
People’s vitamin D levels are influenced by whether they have light or dark skin, where they live, how much time they spend outdoors and by fish and milk consumption. To raise vitamin D without supplements, a person could increase sun exposure for 10 to 15 minutes a day. Eating more fish can help — a 3.5-ounce serving of wild fresh salmon has 600 to 1,000 I.U.’s of vitamin D — but it would take a quart of milk a day to get the recommended dose of vitamin D.
“What we know is that there are a lot of people who are vitamin D deficient based on estimates from national surveys,” said Dr. Michal L. Melamed, assistant professor of medicine at Albert Einstein College of Medicine in the Bronx. “But we don’t know what happens when the curve shifts to the other end. There probably is a risk to having too much vitamin D in the system.”
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