Vitamin D supplements a waste of time?

[HughJass]

Report Questions Need for 2 Diet Supplements
By GINA KOLATA

The very high levels of vitamin D that are often recommended by doctors and testing laboratories — and can be achieved only by taking supplements — are unnecessary and could be harmful, an expert committee says. It also concludes that calcium supplements are not needed.

The group said most people have adequate amounts of vitamin D in their blood supplied by their diets and natural sources like sunshine, the committee says in a report that is to be released on Tuesday.

“For most people, taking extra calcium and vitamin D supplements is not indicated,†said Dr. Clifford J. Rosen, a member of the panel and an osteoporosis expert at the Maine Medical Center Research Institute.

Dr. J. Christopher Gallagher, director of the bone metabolism unit at the Creighton University School of Medicine in Omaha, Neb., agreed, adding, “The onus is on the people who propose extra calcium and vitamin D to show it is safe before they push it on people.â€

Over the past few years, the idea that nearly everyone needs extra calcium and vitamin D — especially vitamin D — has swept the nation.

With calcium, adolescent girls may be the only group that is getting too little, the panel found. Older women, on the other hand, may take too much, putting themselves at risk for kidney stones. And there is evidence that excess calcium can increase the risk of heart disease, the group wrote.

As for vitamin D, some prominent doctors have said that most people need supplements or they will be at increased risk for a wide variety of illnesses, including heart disease, cancer and autoimmune diseases.

And these days more and more people know their vitamin D levels because they are being tested for it as part of routine physical exams.

“The number of vitamin D tests has exploded,†said Dennis Black, a reviewer of the report who is a professor of epidemiology and biostatistics at the University of California, San Francisco.

At the same time, vitamin D sales have soared, growing faster than those of any supplement, according to The Nutrition Business Journal. Sales rose 82 percent from 2008 to 2009, reaching $430 million. “Everyone was hoping vitamin D would be kind of a panacea,†Dr. Black said. The report, he added, might quell the craze.

“I think this will have an impact on a lot of primary care providers,†he said.

The 14-member expert committee was convened by the Institute of Medicine, an independent nonprofit scientific body, at the request of the United States and Canadian governments. It was asked to examine the available data — nearly 1,000 publications — to determine how much vitamin D and calcium people were getting, how much was needed for optimal health and how much was too much.

The two nutrients work together for bone health.

Bone health, though, is only one of the benefits that have been attributed to vitamin D, and there is not enough good evidence to support most other claims, the committee said.

Some labs have started reporting levels of less than 30 nanograms of vitamin D per milliliter of blood as a deficiency. With that as a standard, 80 percent of the population would be deemed deficient of vitamin D, Dr. Rosen said. Most people need to take supplements to reach levels above 30 nanograms per milliliter, he added.

But, the committee concluded, a level of 20 to 30 nanograms is all that is needed for bone health, and nearly everyone is in that range.

Vitamin D is being added to more and more foods, said Paul R. Thomas of the Office of Dietary Supplements at the National Institutes of Health. Not only is it in orange juice and milk, but more is being added to breakfast cereals, and it now can be found in very high doses in supplement pills. Most vitamin D pills, he said, used to contain no more than 1,000 international units of it. Now it is easy to find pills, even in places like Wal-Mart, with 5,000 international units. The committee, though, said people need only 600 international units a day.

To assess the amounts of vitamin D and calcium people are getting, the panel looked at national data on diets. Most people, they concluded, get enough calcium from the foods they eat, about 1,000 milligrams a day for most adults (1,200 for women ages 51 to 70).

Vitamin D is more complicated, the group said. In general, most people are not getting enough vitamin D from their diets, but they have enough of the vitamin in their blood, probably because they are also making it naturally after being out in the sun and storing it in their bodies.

The American Society for Bone and Mineral Research and other groups applauded the report. It is “a very balanced set of recommendations,†said Dr. Sundeep Khosla, a Mayo Clinic endocrinologist and the society’s president.

But Andrew Shao, an executive vice president at the Council for Responsible Nutrition, a trade group, said the panel was being overly cautious, especially in its recommendations about vitamin D. He said there was no convincing evidence that people were being harmed by taking supplements, and he said higher levels of vitamin D, in particular, could be beneficial.

Such claims “are not supported by the available evidence,†the committee wrote. They were based on studies that observed populations and concluded that people with lower levels of the vitamin had more of various diseases. Such studies have been misleading and most scientists agree that they cannot determine cause and effect.

It is not clear how or why the claims for high vitamin D levels started, medical experts say. First there were two studies, which turned out to be incorrect, that said people needed 30 nanograms of vitamin D per milliliter of blood, the upper end of what the committee says is a normal range. They were followed by articles and claims and books saying much higher levels — 40 to 50 nanograms or even higher — were needed.

After reviewing the data, the committee concluded that the evidence for the benefits of high levels of vitamin D was “inconsistent and/or conflicting and did not demonstrate causality.â€

Evidence also suggests that high levels of vitamin D can increase the risks for fractures and the overall death rate and can raise the risk for other diseases. While those studies are not conclusive, any risk looms large when there is no demonstrable benefit. Those hints of risk are “challenging the concept that ‘more is better,’ †the committee wrote.

That is what surprised Dr. Black. “We thought that probably higher is better,†he said.

He has changed his mind, and expects others will too: “I think this report will make people more cautious.â€


http://www.nytimes.com/2010/11/30/health/30vitamin.html

I'm thinking of shitcanning it after reading this, but I'm not familiar with the science behind the supposed necessity of taking vit D supplements (or lack thereof) and I'm too lazy to do any of my own research.

 

[CCS]

Keep your pills. 2000-4000IU is probably ideal. Even a lot of vitamin D propenents say not to go to far over 4000 IU. Those number include what you make from the sun.

Funny how medical boards keep saying low numbers are best, yet every year the requirments go up and up. 250IU, 400IU, now 600IU. They were wrong before, why not now. Answer: they are afraid of getting sued and are overly cautions.

Take finasteride for example. Some doctors say you should wait 10 days without taking finasteride before trying to get your wife pregnant, or 30 days before giving blood or plasma. Finasteride has a 4 hour half life in the blood. At doses below 0.02mg per day, it has virtually no effect on serum DHT levels. A man who took finasteride 24 hours ago probably has the same blood as a woman: low DHT levels, virtually no finasteride. Now I'm not saying anyone act on my statements here and later use them as an excuse to sue me over something that was probably caused by something else. Just do your own research and make your own decisions. Suppose you have a ton of dutasteride in your blood. How much of that do you think is in your semen? Let's see: your semen weighs 5 grams, and you weigh 80,000 grams. ... This is a hard one. The only reason I would hold off is to make sure you are firing live, healthy sperm. FDA even says women should not hold propecia pills... they are in chalk, which I guess is a prime skin delivery vehicle. Maybe that is just FDA covering their butts from a law suit.

Me: I take 2000IU of D3 per day, and get the rest from my food, and a tiny bit of sun that I try to avoid, placing me under the 4000 IU mark.

If you are really concerned about auto

 

[barcafan]

Take your D3, its been proven safe to take 10k IU or more over long periods, its very good for you.

 

[Petchsky]

Last winter I took 5000IU vitamin D supps, mostly because living in England, you don't see much of the sun in winter...not got round to buying any yet, but reading your post Aussie hasn't convinced me not to bother...but I also can't be arsed to look through all the studies. I have on things in the past, but they normally contridict each other anyway.

And, I think what CSS said has merit

"Funny how medical boards keep saying low numbers are best, yet every year the requirments go up and up. 250IU, 400IU, now 600IU. They were wrong before, why not now. Answer: they are afraid of getting sued and are overly cautions."

 

[HughJass]

hmmm

anybody have any data showing the alleged benefits I'll get from taking d3 everyday?

 

[The Natural]

And while, admittedly, it may be entertaining to read competing views on the subject of vitamin D3, our health would best be left in the hands of trained professionals like those at Harvard University who believe that supplementing is a good idea:


"Known as the “sunshine vitamin,†vitamin D is made by skin exposed to the sun’s ultraviolet rays. However, people who live in northern climates or spend little time out of doors year round don’t make enough.

Dietary sources of vitamin D include fatty fish and fortified milk, but it is very difficult to meet daily requirements through diet alone.

Supplements of at least 800 IU per day can help ensure that people receive sufficient amounts of vitamin D.

While vitamin D’s role in strengthening bones is well established, its links to cancer and immune-system malfunctions have only recently emerged. At the Harvard School of Public Health, nutrition experts say large segments of the population don’t get enough vitamin D and are urging the U.S. Food and Drug Administration to raise the daily recommended dose, from 400 international units to 800. For an update on what’s known so far about this important nutrient, the Harvard Public Health Review spoke with HSPH Professor of Nutrition and Epidemiology Edward Giovannucci.

Q: What are the documented benefits of vitamin D?

A: Vitamin D’s best-known role is in building strong bones. We’ve seen plenty of advertising urging people to take calcium to strengthen bones, but people also need to know that calcium can’t do the job well if they’re low on vitamin D. The two micronutrients work synergistically, and a deficiency in either can lead to osteoporosis and associated bone fractures.

Q: What other benefits of vitamin D are researchers starting to uncover?

A: A growing number of human metabolic, epidemiologic, and animal studies suggest important new roles for vitamin D. Certain cancers and immune dysfunction are strongly associated with vitamin D deficiency.

In March, several HSPH and Harvard Medical School colleagues with the Physicians’ Health Study and I found a connection between prostate cancer and low blood levels of vitamin D (specifically, of proteins produced as vitamin D is metabolized). Men also unlucky enough to have certain variant genes involved in vitamin D processing were 2.5 times as likely to develop aggressive, deadly prostate cancers. Moreover, more than two-thirds of the nearly 15,000 men in this study were significantly deficient in the vitamin.

My own research with the large, long-term Health Professionals and Nurses’ Health studies found that populations with adequate vitamin D levels have about half the risk of colon cancer as people who don’t get enough. Other cancers have been linked to lower vitamin D levels, too, particularly those of the digestive tract.

Vitamin D deficiency also translates into a weakening of the immune system and an increased risk of so-called autoimmune diseases, including type 1 diabetes. A recent study led by Associate Professor of Epidemiology and Nutrition Alberto Ascherio found that the higher the vitamin D levels one has, the lower the risk of multiple sclerosis. Last year, HSPH Dean Barry Bloom and collaborators showed that the immune system’s response to some infections is critically dependent on vitamin D.

Their study seems to help explain why people have historically seen sunshine (a major source of vitamin D) as a useful therapy for patients with tuberculosis infections.

Q: How much vitamin D do people need daily?

A: The current daily recommended allowance varies with age from 200 to 600 international units (IU), a standard set by the Nutrition Board of the National Academy of Sciences in 1997. Randomized trials have since found that individuals receiving 800 IU per day had a lower risk of osteoporosis fractures, while 400 IU per day did not show this benefit. Most experts now believe 1,000 to 2,000 IU per day from all sources—sun, diet, supplements—may be what we need for optimum health.

The body is smart: It makes no more vitamin D than it needs. But a total intake greater than 2,000 IU per day has generally not been recommended. This upper limit, imposed for safety’s sake, is probably very conservative. Recent evidence suggests that even doses upwards of 10,000 IU a day aren’t toxic, though such high intakes are not recommended.

Q: What are the best sources of vitamin D?

A: The sun is the most potent source. When the sun’s ultraviolet rays hit the skin, the skin makes the vitamin, which is rapidly absorbed in the blood and can be stored for several months, mostly in the blood and fat tissue. This is why it’s hard to figure out how much supplemental vitamin D people might need.

If you spend a fair amount of time outdoors, you probably don’t need a vitamin D supplement. A light-skinned person living in Boston who takes walks in the summer with the face, neck, and arms exposed for 15 minutes gets enough. A 30-minute, full-body exposure to summer sun at noon without any sunscreen protection triggers the release of about 20,000 IU into the bloodstream. Most of that is stored. Someone dark-skinned would, with the same exposure, generate about half or less as much vitamin D.

For people who rarely get sun exposure or who live in the north, where the body can’t make vitamin D in the late autumn and winter months, even 800 IU per day during these months may be too low. Dark-skinned individuals, whom research suggests are more prone to colon cancer than whites, should probably take vitamin D supplements, considering that their colon cancer risk may be related to insufficient vitamin D.

Evidence shows modest exposure to sun can have long-term benefits. However, I don’t recommend excessive sun exposure because of the well-known risk of skin cancer.

Q: What are other good sources?

A: It’s hard to get vitamin D from diet. That’s why supplements are often a good idea. In the United States, some foods are fortified with vitamin D, such as milk. A glass is supposed to contain about 100 IU but in reality may contain as little as 50 IU on average. To get 800 IU from milk, one would have to drink at least 8 glasses of milk a day.
Fatty fish is the only natural source of vitamin D. A 3.5 oz serving of cooked salmon, for example, has 360 IU; 3 oz. of canned tuna has 200; and 13.4 oz. of canned sardines has 250.

Q: Who might benefit most from supplements?

A: Most people will benefit. The elderly; dark-skinned individuals; obese individuals, in whom fat cells extract vitamin D from blood and hoard it; and those who avoid the sun are all at risk for a less-than-adequate intake or a deficiency. People living in northern latitudes—for Americans, that means north of an imaginary line connecting San Francisco to Philadelphia—only make vitamin D from March through September. Although vitamin D stored from summer sun exposure lasts for some months, most of these individuals will be deficient by late winter.

Q: What’s the bottom line?

A: I suggest taking supplements of no more than 2,000 IU per day of vitamin D without specific medical reasons until researchers have more definitive data on the benefits and risks. Look for supplements that contain vitamin D3 (cholecalciferol), which is three to four times more potent than vitamin D2 (ergocalciferol).
Throughout human evolution, people were naturally and continually exposed to the sun. But today, many of us spend most of our day indoors. Researchers are not recommending massive doses of vitamin D. Instead, we’re saying that many people are vitamin D deficient—and therefore at higher risk for everything from bone fractures and certain cancers to immune-system-related disorders."


(http://www.hsph.harvard.edu/review/spri ... aminD.html)