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The Best Science Writing Online 2012
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Physicians have recommended vitamin D supplements to their patients for a decade, with good reason: dozens of studies have shown a correlation between high intake of vitamin D—far higher than most people would get in a typical diet and from exposure to the sun—and lower rates of chronic diseases, such as cancer and type 1 diabetes. So when the Institute of Medicine, which advises the government on health policy, concluded in November that vitamin D supplements were unnecessary for most Americans and potentially harmful, patients were understandably confused.
The issue exposes a rift among experts over what constitutes valid proof when it comes to nutrition and could affect medical advice on many other supplements. On the one hand are scientists who insist that the only acceptable standard is the randomized clinical trial, which often compares the effects of a medical intervention, such as high intake of vitamin D, with those of a placebo. The scientists who reviewed the vitamin D findings fall heavily into this camp: trials “typically provide the highest level of scientific evidence relevant for dietary reference intake development,” they wrote. Their report set intake levels based only on clinical trial data.
The institute panel, however, discarded a raft of observational studies, in which researchers compare the health of populations who take vitamin D supplements with those who do not. In theory, such epidemiological studies are inferior to clinical studies because they rely on observations out in the real world, where it is impossible to control for the variables scientists seek to understand. Researchers compensate for the lack of control by using large sample sizes—some vitamin D studies track 50,000 people—and applying statistical techniques. According to these studies, high levels of vitamin D are generally beneficial.
In the aftermath of the institute report, some physicians are now taking potshots at clinical studies. In nutrition, they say, true placebo groups are hard to maintain—how do you prevent people in a control group from, say, picking up extra vitamin D from sunlight and food, which can lead to underestimating the vitamin’s benefits? It is also tough to single out the effect of one vitamin or mineral from others, because many work in tandem. “It is wrong-headed thinking that the only kind of evidence that is reliable is a randomized controlled trial,” says Jeffrey Blumberg, a Tufts University pharmacologist.
The next chapter in this debate may come in the spring, when the Endocrine Society releases its own vitamin D guidelines. The organization now recommends higher blood levels of the vitamin than the institute suggested—30 nanograms per milliliter as opposed to 20—which would require supplements. Stay tuned.
This article was originally published with the title Which Pills Work?.
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26 Comments
Add CommentThe previous commenter neglected to copy this fine print from the bottom of that Web page: "Note: This document contains statements ... that are not yet generally accepted by the scientific community. These theories and research fit the medical model of inflammation therapy which has provided considerable supporting anecdotal evidence. We make no claims as to the accuracy of these statements and they will be up-dated whenever new information becomes available."
Reply | Report Abuse | Link to thisBeware quack science.
At a minimum, an independent study should be undertaken to determine the source of discrepancy between the two findings.
Reply | Report Abuse | Link to thisIMO, rather than debating the accuracy of the two methods of analysis on philosophical grounds, there must be some procedural or analytical basis for the differing results. Identifying the cause of the discrepancy should provide a rational basis for determining which result is valid.
The true question is whether vitamin D supplements are unnecessary. Therefore, why would it matter if a controlled study had part of the population obtain vitamin D from sunlight or food? Shouldn't that be a good thing? The only control necessary is no source of vitamin D from supplements.
Reply | Report Abuse | Link to thisNormally I resent long quoted comments like jnbhubregs's, but was drawn in due to my health situation with diabetes (II) and taking 2,000 mg. of D3 per day. I have noticed lowered immunity while taking this dosage, and increased immunity when not taking it. I recall bone pain which decreased when I discontinued taking the statin drug Lovastatin (since a strict diet has brought my colesterol down to the range of 100 and I don't need to lower colesterol further).
Reply | Report Abuse | Link to thisHowever, I still have experienced some bone pain, which went away when I discontinued the D3 supplementation. Unfortunately, I continued the supplementation due to general theory that more D3 is better. Now I'm not so sure, and after reading jnbhubregs's exhaustive quote, will discontinue D3 for a while and observe is symptoms again dissipate.
The use of vitamin D3 in rat poison is telling, considering that I have experienced a few of the symptoms of hypercalcemia (http://www.mayoclinic.com/health/hypercalcemia/DS00976/DSECTION=symptoms), namely excessive thirst, muscle and joint aches, and need for lots of sleep ("lethargy and fatigue"?). Fortunately I have not experienced the really wicked symptoms outlined at this Mayo Clinic link, but enough to warrant a suspension of taking this supplement.
The first comment or explanation of vitamin D tells it ALL...Now, what is the answer, should a normal stay-indoors, stuck on a computer person take vitamin D? Can I substitute red wine instead? More fun!
Reply | Report Abuse | Link to thisSpiff
Spiff, I'm starting to think there are more variables to whether D3 supplementation is recommended. Indoors, computer type, but what is your diet? Your health conditions? I think there are lots of questions that only tests can answer (I'm a member of an HMO that includes extensive blood tests periodically to determine levels of practically everything, and now I'm confused as to whether D3 is poisoning my body and causing bone deterioration.)
Reply | Report Abuse | Link to thisApparently some of the people on this panel had been explicitly rejected from it in previous years.
Reply | Report Abuse | Link to thisAnd one of them, Dr. Grenville Jones, is one of the founders of this company,
http://www.cytochroma.com/about_us/scientific_ad_board/jones.html
which is trying to create a vitamin D analog.
Which, presumably they will market by saying something like 'new research shows that vitamin D doesn't work like we thought it did just look what this government report says, but our new grossly expensive fake vitamin D works great!'
Focalist, I hope you're right because even if I stop taking a 2000 mg dosage (or is it 2000 UI, whatever) per day, I still take Omega 3 gel caps from natural Alaskan salmon farmed in the wild sustainably (that I buy at VitalChoice.com). This has natural vitamin D3, so there's no escaping it.
Reply | Report Abuse | Link to thisI would caution folks with liver and/or kidney problems to get advice from their doctors as to whether excess D3 stresses these organs during filtration (which could cause polyuria or excess urination which could lead to major health problems if caused by a disfunctional liver and/or kidney). As a diabetic (type II) I get regular tests (I think for creatine levels but not sure) to check for impaired liver/kidney function. Thankfully no problems there (knock on wood)!
As a result, I'm very cautious about anything that could stress my liver/kidneys because if these fail, game over. Machines are no fun, unless of course they're amusing contraptions like iPads, perhaps.
Who takes vitamin D ? Vitamin D is a pill . Who sells it ?
Reply | Report Abuse | Link to thisWhen is Scientific American going to print the facts about vitamin D ? If vitamin D is the sunshine vitamin , then where is it ? We need food . Where is the food ? Why is vitamin D sold in drugstores ? Should we ban vitamin D in drugstores , or close all drugstores ?
The article you quote is reasonable only in this respect:
Reply | Report Abuse | Link to thisIf you are suffering from systemic inflamatory response syndrom due to "intracellular bacteria" you do NOT need vitamin D suppliments.
Instead, you need to rush to the nearest emergency room before you die from sepsis.
These researchers probablly do not know, that Quebec had the most cases of MS in girls and women.r It was called Cabin Fever, because during the long winter they stayed indoors and did not get the Vitamin C from the sun. Their men worked outside cutting wood and were seldom affected.
Reply | Report Abuse | Link to thisThe article paints a misleading picture of the IoM's conclusions. The report (available at http://www.nap.edu/catalog.php?record_id=13050) did not say that vitamin D pills don't work or that we don't need higher levels of vitamin D. On the contrary, the IOM upped the adequate intake from 200 IU adequate intake to a 600 IU Recommended Dietary Intake with a 4,000 IU tolerable upper limit. In their analysis, they recommend ignoring vitamin D from sunlight. In their video release (see the video http://iom.edu/Reports/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Report-Release.aspx), it was pointed out that this implied that many people might have to take a vitamin D supplement since it isn't that easy to get 600 IU of vitamin D from diet.
Reply | Report Abuse | Link to thisAs the panel pointed out, we've seen promising observational trial evidence from vitamin E, which was subsequently refuted by randomized clinical trials. So it's best to wait and get good solid evidence.
How hard is it to simply do a blood test for Vit D, comparing the un-supplemented summer and winter blood levels with disease rates?
Reply | Report Abuse | Link to thisGary 7
Do we need vitamin D? Yes. But most people probably get enough. Are some people deficient? Certainly. However, there is very little non-observational, non-correlational evidence that extensive vitamin D supplementation is required.
Reply | Report Abuse | Link to thisReally the only controversy here has been produced by people who have been making extreme claims based upon limited evidence. All of this stuff about vitamin D as a panacea for various ills is speculation and little more. As I understand it, this recent study pretty much just reinforces this point.
As full disclosure, right now I am taking 1500-2000 IU per day because I'm suffering through a rainy Vancouver winter spent cooped up in my lab for 10 hours a day. But that doesn't mean I think supplements are going to cure all my ails or save me from MS.
Honestly, I think most of this "debate" is built on shoddy evidence, public misinformation and fear. But then again, I'm a skeptic.
Yeah, 2000 mg is 80 million IU of vitamin D. :)
Reply | Report Abuse | Link to thisI share your thoughts exactly. Using only observational data can have some severe shortcomings and the case of vitamin D is no exception. In fact, it makes for a superb example. Vitamin E and hormone replacement therapy are two examples. But, in the case of vitamin D, you have the the distinct possibility of reverse causation and all of the confounders associated with it, each and every one of which do a better job at explaining why these divergent vitamin D levels are found in people with and without various diseases and conditions. Without going into too much detail, if you have one of these various conditions, you're generally less likely to be active and go outside and get exposed to sunlight, which, all alone, can explain many of these findings.
Reply | Report Abuse | Link to thisYet, it seems more likely that it is a combination of the above as well as the fact that myriad associations between factors associated with a healthy lifestyle and vitamin D levels have already been found. They have already found that those with higher vitamin D levels are more likely to be physically active, consume less read meat and more fish, less likely to smoke, more likely to have less clothing when going outdoors, due to being in better shape (think people wearing less clothing at the beach in the summer), have more muscle, less fat, and are from a higher socioeconomic level than their counterparts with lower vitamin D levels. Of more interest is that vitamin D levels are directly related to physical activity and have been used as a way to determine outdoor activity as well. So, which is more likely, that vitamin D is the influencing factor? Or, that consuming less red meat, more fish, smoking less, exercising more and being in better shape (i.e., less fat mass and more muscle) are the factors that are associated with reduced disease rates?
As a direct example, obesity is associated with low vitamin D levels. Does this mean supplementing with vitamin D will cure obesity? Of course not! People that are obese have lower vitamin D levels because of lifestyle factors (i.e., staying indoors and being less likely to consume foods with vitamin D, multivitamins, etc.). Vitamin D is nothing more than a byproduct of a poor lifestlye, not the cause of it.
Randomized controlled trials are the only way to determine whether these observational studies have any merit and sure enough, every one I've found has shown little to no benefit from high doses of vitamin D. See next post for more info:
http://www.ncbi.nlm.nih.gov/pubmed/16595781
Reply | Report Abuse | Link to thishttp://www.ncbi.nlm.nih.gov/pubmed/20681994
http://www.ncbi.nlm.nih.gov/pubmed/14687355
http://www.ncbi.nlm.nih.gov/pubmed/20439594
http://www.ncbi.nlm.nih.gov/pubmed/19850735
http://www.ncbi.nlm.nih.gov/pubmed/19512949
http://www.ncbi.nlm.nih.gov/pubmed/19276997
http://www.ncbi.nlm.nih.gov/pubmed/19402866
http://www.ncbi.nlm.nih.gov/pubmed/19321573
http://www.ncbi.nlm.nih.gov/pubmed/19276997
http://www.ncbi.nlm.nih.gov/pubmed/18663544
http://www.ncbi.nlm.nih.gov/pubmed/20843488
http://www.ncbi.nlm.nih.gov/pubmed/20054189
http://www.ncbi.nlm.nih.gov/pubmed/17923796
http://www.ncbi.nlm.nih.gov/pubmed/17616775
http://www.ncbi.nlm.nih.gov/pubmed/21194910
http://www.ncbi.nlm.nih.gov/pubmed/20305368
http://www.ncbi.nlm.nih.gov/pubmed/20596692
http://www.ncbi.nlm.nih.gov/pubmed/21083597
What such statistically based studies cannot tell me or any other individual is what effect taking extra doses of vitamin D will have on them personally. Each of us is a unique biochemical organism living in an environment that may be quite similar or vastly dissimilar to other individuals, so the studies add nothing really in helping us make informed choices about our health. It is still one big craps shoot.
Reply | Report Abuse | Link to thisThis "controversy" is not a controversy at all. The IOM has been corrupted by their panel not having one single real vitamin D scientist on their panel. Not Robert Heaney, Hollick, Hollis, Vieth or any other expert. However, it did have a scientist, Dr. Glenville Jones, who is entirely compromised by her for-pay relationship with drug companies (CYTOCHROMA) who are making vitamin D analog drugs. If it did have any of the dozen real vitamin D expert scientists on the panel, their recommendations would be much higher AND be credibly based on the available scientific studies. As it happened, these same experts gave their recommendations to the panel, which ignored them, and these experts have made statements about the inadequacies of the IOM recommendation, including statements that the biggest problem was that the IOM had created credibility questions that never have happened in it's history before. It's appalling that the IOM has now been tainted this way. See: http://www.michaelmooney.net/VitaminDRecommendationsInadequate.html
Reply | Report Abuse | Link to thisAnd the proponents that are strangely obsessed with having everyone take large doses of vitamin D for unproven non-skeletal effects don't have any potential conflicts of interest? So none of them are sponsored by any organizations that would benefit from people taking more vitamin D? Maybe perhaps an indoor tanning industry? Maybe a supplement manufacturer that sells vitamin D? Exactly.
Reply | Report Abuse | Link to thisI think the panel did a great job considering what it was tasked with. It's difficult to make a blanket recommendation when you're tasked with trying to figure a dose out for millions of people. I've had my vitamin D levels monitored and even at their lowest, I'm still above 35 ng/ml (no sun exposure and 600 IU/day from food and multivitamin consumption) and I easily get into the 80's and 90's during the summer (and I don't live in a state known for sunshine or outdoor activity). There is a significant portion of the population that already have more than adequate vitamin D so an increase is unnecessary and may even cause harm in a small subset. Is it worth that? Not to mention the unknown effects of these high dose protocols.
And if we want to start having a real scientific debate about the subject, how about starting with the scientific literature itself instead of this political nonsense about who has ties to what. Like I tried to do in an earlier post, let's examine these purported benefits by comparing what many of these proponents are claiming from observational studies with results of randomized controlled trials. In doing so, I am quite convinced thus far that vitamin D levels (when it comes to non-skeletal effects) are largely a byproduct of multiple lifestyle factors and health status, not the other way around. People seem to forget that correlation is not causation and the lessons of the past (vitamin E, female HRT). This is why RCT's are crucial, yet proponents are conveniently ignoring them.
There is no conspiracy, the panelists are simply being conservative while waiting for evidence to support higher intakes as they wish to do no harm. The data are not there yet. Yes, we need vitamin D (that was established long ago), but what is "optimal" for an entire population hasn't been truly determined. All that is really known is at what level deficiencies which cause (confirmed) maladies, tends to occur.
Take a look at these observational studies for yourself and then compare them with the few RCT's to date. You'll find that the RCT's, in virtually every case, aren't supporting the claims made based upon the observational epidemiological data. If non-white, obese, high-LDL-ridden, low muscle mass, high fat mass, less educated, higher red meat and saturated fat consuming, smoking, hypertensive, high blood glucose, less fish consuming, non-physically active people are that way because of low vitamin D, why doesn't high dose vitamin D supplementation correct any of these (behavior, education and race obvious exceptions of course) in the RCT's? Why is it that when observational studies adjust for physical activity, education, and lifestyle factors in general, most, if not all of these associations are no longer significant for vitamin D? Confounders and reverse causation are the likely culprits.
Reply | Report Abuse | Link to thisIf you go to DOCSTOC and look at my documents:
Reply | Report Abuse | Link to thisTrace elements & active transport
Air pollution & Alzheimer's Disease
Protons, life & evolution
which explain how vitamin D works, then the need for supplements becomes easier to understand. By converting sunlight into chemical energy, it enables proper use of fluorine to control bone metabolism and protects the brain against dementia.
Ms. Piume Bentarage - Sri Lanka
Reply | Report Abuse | Link to thisVitamin D is an element where it act on the Melenin of the skin and controlls the coagulation of the blood.But I found in southern hemisphier where black skin is they have more melanine level in the skin than that to the Northern hemispher of the world. I wonder what is the reasone behind this? Why black skin could not make to white skin if this problem lies with the level of Vitamin D relation. I hope there should be a way to make the skin.What will happen if Black skin person not used vitamin D? What is the co-relation of not using of vitamine D and taking appropiate vitamin D? Can peopel servived with out vitamine D? What is the minimam level of vitamin D requiement for a human to servive? Is vitamin D is an eccential for human body?
As usual ennui is completely incoherent in his posts.
Reply | Report Abuse | Link to thisWhy would we do anything based on a suggestion from a complete stranger on the internet? You have absolutely no authority to me.
Reply | Report Abuse | Link to thisDear bucketofsquid
Reply | Report Abuse | Link to thisIf you won't listen to a stranger, you must use your own intelligence. My authority comes from the application of logic to a lifetime's experience.