Talk:Vitamin D/Archive 4

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AAAS workshop on vitamin D (part 2)

The article is going to have to reflect the conclusion of the Institute of Medicine of the National Academies "Scientific evidence indicates that calcium and vitamin D play key roles in bone health. The current evidence, however, does not support other benefits for vitamin D or calcium intake. More targeted research should continue. Higher levels have not been shown to confer greater benefits, and in fact, they have been linked to other health problems, challenging the concept that "more is better." Overagainst (talk) 19:06, 17 April 2011 (UTC)

Even if we were to decide to do this, you would still have the problem that the IOM recommendation for 600 IU per day is for US citizens, while Wikipedia is written for a World Wide audience. Mr. Bongo who emigrated from Congo to Edinburgh Scotland may also read this article, but he lives almost as far north as Churchill, Canada where polar bears are frequently seen in Winter and he is a black as coal. In the US and Canada, not many people live this far north. Even inhabitants of New York are considered to have a potential Vitamin D problem in winter, because the flux of UVB light is then too low, yet New York is on a similar latitude as Madrid, Spain! Count Iblis (talk) 20:34, 17 April 2011 (UTC)

(When I give a link followed by a quote the original text can generally be found at the link, usually on the same page)

Dietary Reference Intakes for Calcium and Vitamin D "To help clarify this issue, the United States and Canadian governments asked the IOM to assess the current data on health outcomes associated with calcium and vitamin D, as well as updating the nutrient reference values, known as Dietary Reference Intakes (DRIs.) In this report, the IOM proposes new reference values that are based on much more information and higher-quality studies than were available when the values for these nutrients were first set in 1997. The IOM finds that the evidence supports a role for vitamin D and calcium in bone health but not in other health conditions. Further, emerging evidence indicates that too much of these nutrients may be harmful, challenging the concept that “more is better.”" (I think the IOM is aware of the existence of people with very dark skin in Canada (and Alaska). Indeed, as already mentioned many of the First Nations -not Inuit- people in Canada are rather dark skinned although their traditional diet was Caribou which contains hardly any vitamin D) Overagainst (talk) 18:40, 18 April 2011 (UTC)

Ok. but then, since Vitamin D only acts via regulating gene expression, you would expect that indiginous people who don't get enough vitamin D have evolved to do without it. If a gene needs to be turned on for the body to function optimally, there is no reason why that won't happen eventually, vitamin D or no vitamin D. Presumably, letting vitamin D control the expression of certain genes maximizes survival probability under usual circumstances. Count Iblis (talk) 17:13, 19 April 2011 (UTC)

"you would expect that indiginous people who don't get enough vitamin D have evolved to do without it". Virtually everyone gets enough vitamin D from the sun including indigenous Canadians. What happens when they get more than they need by the evolutionarily unprecedented route of oral supplementation is beginning to be understood:" emerging evidence indicates that too much of these nutrients may be harmful" Overagainst (talk) 21:28, 19 April 2011 (UTC)

Evolution is not good at correcting deficiencies. For instance you would expect evolution to have evolved black chlorophyll - but I see green everywhere. -- cheers, Michael C. Price ^talk 18:21, 19 April 2011 (UTC)

Greg Cochran on evolution"The power of natural selection decreases with age, especially after the reproductive years, so bad stuff happening to 80 year olds is no anomaly. If homosexuality hit at 85, like Alzheimer's, it wouldn't be anomalous. But of course that is not the case. It's an evolutionary anomaly. Almost all evolutionary anomalies of comparable size are caused by infection. It's the way to bet. Failure of key adaptations, in the absence of some kind of exterior insults, is rare. It has to be, else how could you walk and talk and say silly things? Do you realize how many different organs and biochemical systems have to work correctly in order for you to successfully have breakfast and read the comics? Hundreds, at minimum - this is why biochemistry texts are _thick_. If correct function of hundreds or thousands of separate biochemical mechanisms is required in order for adequate performance at an organismal level, the probability of failure of any one system is and _has_ to be very low. And natural selection keeps that probability low. That is why geese seldom fly north for the winter. It is why a fox seldom attacks a human - unless it has rabies." Overagainst (talk) 20:59, 19 April 2011 (UTC)

I'm not sure what part of the green chlorophyll example - a glaring inefficiency that has persisted for c 2 by - was unclear. How does evolution cope with, say, a zinc deficiency? Do we evolve a substitute for zinc fingers? I don't think so. Why is vitamin D any different? -- cheers, Michael C. Price ^talk 11:06, 20 April 2011 (UTC)

Fred Hoyle suggested that green chlorophyll is adapted to outer space, even if that were true, if black chlorophyll offered an overall advantage on earth it would have supplanted green by now. Zinc is fundamentally different in that it can not be synthesized, 'vitamin' D can be synthesized by humans. There are example of how natural selection can find a substitute for vitamin D how about the Mole Rats, they seem to be doing OK; Naked Mole-Rat: A New Long-Living Model for Human Aging Research. I think it's important to grasp that the UV-B which strikes the average person in northern regions like Canada or Europe is NOT a bare minimum, actually it would synthesize far too much vitamin D - hundreds of thousands of IU per day in the summer if there was no limiting mechanism. There are several mechanisms to limit vitamin D synthesis which modern Europeans have retained. There is the switch off in skin synthesis after 10-20 minutes (or 1 minute in some circumstances Vitamin D production depends on ultraviolet-B dose but not on dose rate: a randomized controlled trial.); there is the system of vitamin D metabolism which even Vieth 99 calls 'a system better designed to cope with an abundance of supply, not a lack of it"; there are also alleles which reduce the effectiveness of the vitamin-D binding protein, and their homozygotes account for 9% and 18% of the subjects in Sinotte et al., 2009. So the idea that UV-B exposure is directly proportional to vitamin D synthesis and/or vitamin D levels is wrong. The only evidence that vitamin D has been in short supply for humans in temperate latitudes is that in Europeans skin turned white, but the simple latitude /UV hypothesis is not supported by the date for skin lightening mutations. (Some people have suggested that white (and black) skin has nothing to do with vitamin D.) Anyway, this rather speculative discussion is not really relevant to the article which must reflect the established scientific consensus as given by the IoM report. Overagainst (talk) 20:16, 20 April 2011 (UTC)

To conclude, vitamin D synthesis is not that different from zinc, since the former depends on the availability of coenzyme and minerals (and UV) which we can't synthesize. So there is no basis for claiming that studies looking for a connection with health lack theoretical basis and are just deluded, wishful thinking fishing expeditions. -- cheers, Michael C. Price ^talk 20:38, 20 April 2011 (UTC)

Do the cited IOM conclusions really state that "Scientific evidence indicates that calcium and vitamin D play key roles in bone health. The current evidence, however, does not support other benefits for vitamin D or calcium intake. ? If the IOM really made that proveably untrue statement, that makes the IOM an unreliable source and should therefore not be cited in Wikipedia. It sounds as obsolete as something copied from a report dated half a century ago. Greensburger (talk) 02:44, 18 April 2011 (UTC)

I think, reading the entire IOM report, you'll find that perhaps "does not prove rigorously those other benefits", is what the IOM report really says. One can argue with that as well, of course. But for argument's sake, accepting this, it is still an arbitrary choice to keep the RDA at 600 IU if one isn't more than 99.999% sure that there are other benefits at higher doses. Also, it is quite clear that the IOM wanted to deal with another problem: Many US citizens are demanding Vit. D tests, thereby straining the blood laboratory test system in the US. These are mostly healthy people who want to reduce their chances of geting serious diseases like cancer (I think that the IOM report itself mentions this, but at least JoAnn Manson, the leader of the IOM panel has said that she considers this to be a huge problem that has to be dealt with, in an interview given before the report was completed).

So, by saying that the evidence isn't clear and by keeping the RDA low because of that, they have tried to stop the flood of Vit. D tests being performed. But then, not everyone takes vitamin D supplements to prevent cancer. I take them because I'm pretty sure it leads to better general fitness. Count Iblis (talk) 14:39, 18 April 2011 (UTC)

(1) The IOM really did make that statement. (2) Just because a reliable source disagrees with your POV, that does not make the source unreliable. (3) If you think that the IOM report is an unreliable source in the context of this article, the reliable sources noticeboard is thataway. (4) This page is no place for amateur analyses of reliable sources, so until such time as another reliable secondary source reaches a different conclusion, the article needs to report what the reliable secondary source that we have says. --RexxS (talk) 18:18, 19 April 2011 (UTC)

And if other reliable sources disagree, we should also report what they say. The problem is that if the IOM is deemed infallible, then any other sources, even those published in peer-reviewed science journals, that conflict with IOM findings, will be deemed unreliable sources solely because they conflict with IOM findings. Both sides should be reported. Greensburger (talk) 23:50, 19 April 2011 (UTC)

Perhaps Europeans evolved a white skin, so that the vitamin D variations they would experience during the year would be a strong enough signal for the body to use to regulate important functions. If the body "knows" in Fall that in a few weeks time Winter is coming, it makes sense cut a bit back on energy expensive functions, such as the immune system. It is no good having a slightly lower risk of getting cancer if you are not going to have enough fat reserves to survive Winter if there are food shortages. And, obviously, the less fat you have, the sooner in Fall you should start cutting back. Since vitamin D is stored in fat, the less fat you have the sooner your vitamin D levels are going to go down, so Vit. D naturally implements this optimal algorithm for survival. Count Iblis (talk) 21:14, 16 April 2011 (UTC)

New approach in determining RDA

This is announced in this article, the results are yet to come.

What I've read elsewhere about the research Wagner et al. are conducting is the following. Instead of looking at serious illness for which the evidence is not always conclusive and controversial, one can look at the need for infants, which is far less ambiguous. Babies need about 400 IU per day and they drink about 1 litre of breast milk. Since the breast milk of most women does not provide for the baby's vitamin D needs (it typically contains 25 IU/litre), supplementation for babies is recommended (and that recommendation is also not controvesial, the IOM e.g. also recommends this)

You can now make the leap from babies to adults, by asking what the mother's calcidiol level should be so that her breast milk does contain 400 IU per litre. What I've read elsewhere is that the preliminary results are that the calcidiol levels should be in the range of 120 to 150 nmol/l and to achieve those values, about 6000 IU/day is necessary.

I don't know about the details, but I assume that the next step would be to look at increasing the calcidiol levels in women to see if the vitamin D levels in the milk flattens out at some level X. Then X would be the RDA for babies and the calcidiol level for the mother where you are a bit above the minimum to reach X would be the minimum target for adults. But what is already clear from what has been leaked about the research result is that you're looking at an RDA for adults of about 10,000 IU/day. The UL will then presumably have to be increased to, say, 20,000 IU/day. But these figures, of course, refer to total intake, i.e. supplements plus what you get from Sun exposure. Count Iblis (talk) 02:59, 15 April 2011 (UTC)

Equivalence of D2 and D3?

The article states under Measuring vitamin D status: "One study found that vitamin D3 raised 25-hydroxy-vitamin D blood levels more than did vitamin D2,[73] but this difference has been adequately disproved to allow reasonable assumption that D2 and D3 are equal for maintaining 25-hydroxy-vitamin D status.[74]" where reference 74 is to Michael Holick.

A new Holick report published in June 2011[1] is quoted as saying that D3 (animal-derived) is 10 times more potent than D2 (plant-derived) following a single dose of 50,000 IU from either source. Two weeks later, D3 was still peaking whereas D2 had fallen back to baseline.

The question remains of whether the important measurement is the blood level of D2 or D3, or the converted compound from either source -- 25OHD. It's possible, for example, that the above differences at two weeks could result from D2 converting faster to 25OHD than D3 does, and therefore would be more efficient.

Comments? --Zefr (talk) 21:57, 9 June 2011 (UTC)

Authors and abstract of the published guidelines are here[2] and MedPage news summary with a video of Holick here.[3] --Zefr (talk) 22:18, 21 June 2011 (UTC)

Should be included in the article. More in general, the current article doesn't say a lot about treatment of Vit. D deficiency (for which sometimes Vit D2 in high doses is used). Count Iblis (talk) 15:17, 23 June 2011 (UTC)

Results of new study published

See here. This study debunks pretty much everything that is written in this Wiki-article, it clearly points to the so-called "megadoses" being absolutely necessary for good health. While it says that supplements didn't have much effect, note that this study ran for ten years and high dose supplement use was not common until recently, and in Europe it actually still isn't to this day. Supplements containing more than 400 IU or 1000 IU are outlawed in almost all European countries.

So, a study like this that points to UVB exposure being the dominant factor is a highly significant pointer toward the neccessity of at least 10,000 IU/day of vitamin D. Count Iblis (talk) 15:25, 23 June 2011 (UTC)

Endocrine society

Dr Michael Holick led the Endocrine+Society 'Taskforce' which came up with 'Clinical Practice Guidelines' "these guidelines for endocrinologists and other clinicians go a long way towards providing a sensible, evidence-based rebuttal of the Institute of Medicine’s (IOM’s) recently released recommendations". Here is a little background on Hollick In 2004 "A Boston professor of dermatology has been asked to resign because he advocates moderate exposure to sunlight. Michael F. Holick, MD, PhD, a professor at Boston University, was asked to resign in April from BU's Department of Dermatology because of a book he wrote, in which he describes the importance of sunlight in boosting vitamin D levels. He was also severely criticized for his ties to the indoor tanning industry. Department chair Barbara Gilchrest, MD, told the Boston Globe that the book "is an embarrassment for this institution and an embarrassment for him." As demanded, Holick resigned his post. [...]his statements, superficially at least, seem to be at odds with the medical profession's consensus on the damaging effects of sunlight." Here is the soi-disant 'worlds leading expert on Vitamin D' plugging his book Overagainst (talk) 15:31, 17 July 2011 (UTC)

Old news. Since then the consensus has moved. -- cheers, Michael C. Price ^talk 15:34, 17 July 2011 (UTC)

Please give a reference for the assertion that dermatologists changed their mind about the dangers of sunbathing . I think you'll find Holick's advice on sunbathing is still way out of line with professional opinion in the dermatology community.And now (after the Iom report on vitamin D) he is way out of line with the IoM on vitamin D. The point is that Holick's positions on sun exposure and D supplements are in no way part of a new consensus. Gilchrist called his ideas 'shlock science'. To be fair Holick seems to understand some of the implications of the fact that, as he puts it, " Vitamin D made in the skin lasts at least twice as long in the blood as vitamin D ingested from the diet.". I would be interested in knowing how much vitamin D you take yourself Michael.Overagainst (talk) 16:49, 17 July 2011 (UTC)

Not sure about Michael, but I'm doing ok. with the dose I take. Count Iblis (talk) 17:25, 17 July 2011 (UTC)

Same dose as Iblis. -- cheers, Michael C. Price ^talk 17:27, 17 July 2011 (UTC)

10,000 IU is not known to be safe, even in the medium term. That's why no research being done with anything like that that amount. The highest dose being given in a proper study is the one Iblis mentions below (a study of 5000IU/d plus fish oil currently in it's early stages). R.Vieth opines but gives no studies (there are none) attesting to the long term safety of ingesting 10,000IU a day. I believe there is a single study of vitamin D supplementation of 4000IU a day but it did not last more than a few months. That is why the IoM set a Tolerable Upper Intake Level of 4000 IU. Overagainst (talk) 19:04, 17 July 2011 (UTC)

Not known to be safe and known to be not safe are two different things. BTW the authors of the Nov 2007 scientific american article on vitamin D, Luz E. Tavera-Mendoza and John H. White, take 1000 and 4000 IU /day respectively. -- cheers, Michael C. Price ^talk 19:15, 17 July 2011 (UTC)

Frank C. Garland was not exactly in the fullness of his years; does Robert P. Heaney look healthy to you; does Dr. Reinhold Vieth ? Overagainst (talk) 20:14, 17 July 2011 (UTC)

Depends on their ages. -- cheers, Michael C. Price ^talk 20:30, 17 July 2011 (UTC)

FYI, Frank Caldwell Garland (June 20, 1950 – August 17, 2010) he had been battling Esophageal cancer for a year. Heaney looks terrible and you know it. Vieth has a bloated torso and spindly arms legs and neck. Both are very poor advertisements IMO. Overagainst (talk) 21:29, 17 July 2011 (UTC)

Wake me up when you have Heaney's and Vieth's ages. zzzzzzzzzzzzzzz -- cheers, Michael C. Price ^talk 21:34, 17 July 2011 (UTC)

I've got to admit that some D advocates look good for their age He is also zzzzzzzzzzzz sleeping, sleeping forever. Michael C Price is putting his life into fast forward with his pill popping(see following link) 'What would a 55y/o be CRAZY not to take?' The advice of the IoM. Overagainst (talk) 09:03, 18 July 2011 (UTC)

Only time will tell - although by your reasoning I should be dead already, since I've been in fast forward for 30 years. -- cheers, Michael C. Price ^talk 10:28, 18 July 2011 (UTC)

If possible, could we steer this conversation back on topic to the article itself? Article talk sections are not a forum (See WP:NOTFORUM). Although I find the conversation interesting, we should keep the discussion on track about the article itself, and not about fellow editors supplementation routines. Agreed?  Leef5  ^{TALK | CONTRIBS} 11:26, 18 July 2011 (UTC)

I think it is relevant to point out that Michael C. Price has taken various supplements. In 2004 he was taking (among other things) an whopping 150,000 IU of beta catotene, a substance which subsequently has been proven to cause cancer in those supplementing it at much lower levels that he took (and doubtless still would be taking if trials had not proven it to be dangerous). When he advocates taking an astronomical amount of vitamin D against the advice of the IoM it should be remembered that he has a track record of being terribly wrong.

Michael C. Price says "by your reasoning I should be dead already, since I've been in fast forward for 30 years". In 2004 Michael C. Price was only taking 2400 IU of vitamin D, it is irresponsible of him to imply that he's living proof that taking 10,000 IU of vitamin D a day for 30 years is harmless. The continuing existence of people who have been taking massive doses of vitamin D merely proves that (because humans are tough enough to cope reasonably well with all sorts of insults to their health) it requires large scale carefully designed studies or metastudies or meta meta studies (like the IoM report on vitamin D) to find adverse effects. Sure, some people can cope with high dose vitamin D supplements but the IoM has found that they offer no benefit and may damage health. The article must reflect the scientific consensus among qualified professionals as given in the conclusions of the IoM report. It can be mentioned that some figures disagree with the IoM but a dissenting view should not be presented as a countervailing one. Overagainst (talk) 12:57, 18 July 2011 (UTC)

"...but the IoM has found that they offer no benefit and may damage health." And this is the central point of disagrement w.r.t. editing this article. This statement should be qualified, what the IoM did was to try to establish if the recent results that suggest that there are benefits consititute "proof beyond a reasonable doubt". They found that as things stand now, you can still have reasonable doubt. Accordingly, the IoM jury returned a not-guilty verdict for the charge that vitamin D is involved in improving non-bone health at high doses. Count Iblis (talk) 14:46, 18 July 2011 (UTC)

There is no need for you to try and explain the IoM to us Iblis. The IoM committee is made up of experts, people who are superbly qualified and know how to explain things. We can just read their words "Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. [...] Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use" These conclusions of the IoM should be quoted in the article. The reasons that that certain lesser figures give for disagreeing with the IoM can be briefly mentioned. Overagainst (talk) 20:18, 18 July 2011 (UTC)

Interesting word "may" in the middle of that IoM statement! Iblis's analysis is correct. The IoM's verdict is "not proven". -- cheers, Michael C. Price ^talk 21:44, 18 July 2011 (UTC)

The IoM's team of acknowledged experts exhaustively examined all of the evidence and found there is no benefit whatsoever from Vitamin D supplementation.

"Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. ".

You are now reduced to claiming that, because the IoM report's assertion of an association between adverse health outcomes and 'current levels of supplement use' is not phrased in terms of absolute certainty, it should not be the central authority and reference for the article. I would just like to point out to the unwary reader that Michael C. Price has a track record of refusing to accept that supplements cause excess mortality; he thought Patrick ("AZT, the first prescribable anti-HIV drug, is potentially harmful, and proving less effective than vitamin C") Holford's criticism of a peer reviewed meta study of anti oxidants and mortality was 'sound'. It wasn't as has now been conclusively established (see Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2007). "Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis". JAMA 297 (8): 842–57.)

As you have introduced notions of forensic responsibilty into the discussion let me say that 'not proven' is the 'bastard verdict'. Overagainst (talk) 09:11, 19 July 2011 (UTC)

ZZZZZZZZZZZZZZZ -- cheers, Michael C. Price ^talk 13:30, 19 July 2011 (UTC)

Hazzzzzzzard ratios of risk of death according to baseline serum 25OHD level. Overagainst (talk) 14:47, 19 July 2011 (UTC)

As with almost everything in science which isn't 100% understood, it matters what your prior assumptions are. Results on hypothesis testing depend on what your null hypothesis is, or you can proceed in a Bayesian way, and then you need to assign prior probabilities. So, you can't escape making prior judgements based on some vague picture of what you think is most likely to be true. Alternatively, if you approach the problem from wanting to rule out that vitamin D supplements may do harm, then you need to choose a null hypothesis that assumes that vitamin D does do harm in those doses where it hasn't been rigorously ruled out. That is what the IoM did. Count Iblis (talk) 15:12, 19 July 2011 (UTC)

The IoM committee members are scientific experts who are more than capable of delivering an objective report. Overagainst (talk) 17:31, 19 July 2011 (UTC)

Yes, but they have themselves explained in the report itself, in a susequent BMJ article and in interviews, how they have analyzed the data and what their rationale for that was. That information should also be included when we give the IoM's conclusions.

If we don't do this, then the IoM's conclusions read like the matter having been settled in favor of the hypothesis that large doses are of no benefit, but that is in conflict with the opinion of the IoM members themselves, let alone the critics of the IoM. The critics of the IoM reject the report mainly because they disagree with the IoM's choice of the burden of evidence. So, if we give the views of the critics in this article, we also have to specify clearly the way they look at this. You can't e.g. include a statement cited from some article by Vieth and "rebut" that by a statement from the IoM report, because they make different assumptions. Count Iblis (talk) 17:54, 19 July 2011 (UTC)

Here is an except from a NYT article quoting Dennis Black, a reviewer of the IoM report who is a professor of epidemiology and biostatistics at the University of California, San Francisco. (I think he may know about null hypothesis ect)

"'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.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.”"

I think you are misrepresenting both the IoM (as a bunch of scare tactic merchants) and their report (as of equal standing to dozens of other reviews). The IoM committee are quite impartial and their report stands above all other authorities. The members are chosen because they are experts and have no conflict of interest. The IoM were tasked with reviewing all the available data (a vast undertaking) and they did just that. The report of a committee is going to be a matter of reaching a consensus and the fact that some committee members may dissent from certain parts of the report simply replicates the situation in the wider scientific community. There is never going to be perfect unanimity. Look at the Dietary Reference Intakes for Calcium and Vitamin D (2011) : Perspectives on Evaluating Data for Determining Reference Values for Vitamin D and Calcium You can see that the big names in pro-supplementation including Vieth, Hollis, C.Garland, Heaney and Holick were all allotted time to make any points they wished. And as you point out there were those on the committee who were friendly to the idea of supplementation, that shows that the IoM picked a cross section of opinion. The IoM's conclusions are in no way merely one side of an ongoing controversy as you seem to think. Wikipedia articles have to accurately represent the scientific consensus, while dissenting views can be mentioned they can not be given equal weight. The article must make it clear that the IoM report represents the balance of expert opinion in the scientific community. Overagainst (talk) 19:24, 19 July 2011 (UTC)

There might be some IOM conflicts of interest, actually. I read that one of the authors, Glenville Jones, PhD, seems to have conflicts due to his work with Cytochroma and advisory board position at Receptor Therapeutics. Has anyone got more details on this potential conflict? 99.97.37.127 (talk)

POV tag

Someone who doesn't know that there is a vigorous debate in the scientific community about appropriate calcidiol levels, about whether vitamin D does anything else besides beng involved in calcium metabolism, and if so, what exactly, and if the evidence for that is strong or weak etc. etc. would not get anything at all about this from the current version of the aticle.

Such a reader, who only reads this article and does not check the IOM report, but simply takes the referenced statemens to be "correctly verified", would belief that the isues have been settled in the favor the idea that 600 IU/day is enough and that vitamin D's main role is in bone health. Such a reader would probably think that most scientists support this idea (otherwise, one whould think that there would be a vigorous debate in the scientific community, but then this Wiki article would mention something about this).

Count Iblis, what the IoM says is slightly different to "issues have been settled in the favor the idea that 600 IU/day is enough". The IoM has concluded that is a suffient oral intake for someone (of a certain age )who gets minimal sun exposure. This is important because the claims that dark skinned people need more are irrelevant when minimal sun exposure is assumed. The IoM have not issued a recommendation for those with normal sun exposure I think. Overagainst (talk) 11:04, 16 July 2011 (UTC)

So, I tink a POV tag is justified. The article should, at the very least, mention that many experts in the field completely reject the IOM's conclusions, there are plenty of peer reviewed articles in relevant journals that make this abundantly clear. Count Iblis (talk) 15:44, 15 July 2011 (UTC)

It is not POV,I gave clear references for every one of the assertions in my edit. It is denialism to claim that an exhaustive report from a committee of the Institute of Medicine of the U.S. National Academy of Sciences is not sufficiently authoritative to supersede other, (obviously lesser) references. References are not all equal. here are some quotes from Wikipedia:No original research If your viewpoint is in the majority, then it should be easy to substantiate it with reference to commonly accepted reference texts Tertiary sources are publications such as encyclopedias or other compendia that mainly summarize secondary sources. Wikipedia is a tertiary source. Many introductory undergraduate-level textbooks are regarded as tertiary sources because they sum up multiple secondary sources. Policy: Reliably published tertiary sources can be helpful in providing broad summaries of topics that involve many primary and secondary sources, especially when those sources contradict each other The IoM report was commissioned by the US and Canadian governments, the report of the IoM represents the gold standard for medical opinion. "Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake (...)“ Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use. ". Is this POV too? "In 1988, a panel of the Institute of Medicine of the U.S. National Academy of Sciences found that the evidence that HIV causes AIDS is scientifically conclusive". As it stands the article is misleadingly giving equal weight to criticism of the IoM's tertiary source report from what are secondary sources at best. I ackowledge the article should make mention of the fact that that certain figures disagree with the IoM but this was done because the quotes from the IoM made it clear that there are all sorts of claims for vitamin D. Overagainst (talk) 09:11, 16 July 2011 (UTC)

It is POV, because the IOM used a double standard see if the evidence for the benefits at higher doses stands up to scruteny compared to potential risks (i.e. extremely high threshold for verifying results claiming benefits, extremely low standards for suggestions of harm). They don't make a secret about it, the issue is not whether or not the IOM was justified to do that. The POV issue comes about when the Wiki article presents the IOM's conclusions, but then doesn't mention this double standard explicitely.

Let me give a simple example. Suppose that particle physicists claim that the Higgs particle has been observed with very high degree of certainty, say the signal is 3 sigma's above the noise. But a review panel rejects the claim of this discovery because to qualify, the signal has to be 5 sigma's. It would then be wrong to write in Wikipedia that "a signal was seen but that a review panel rejected this as a detection of the Higgs particle because of insuffcient statistical significance", without giving the details here.

If that is your idea of a simple (accessible) example I'd hate to see you showing off ! Overagainst (talk) 13:29, 17 July 2011 (UTC)

Even though this could be a literal quote and would seem to meet all the Wikipedia guidelines, it would be extremely misleading, as most people reading that sentence would be led to think that the signal was what they personally would consider to be not very signifiant, like less than 2 sigma's. Count Iblis (talk) 16:02, 16 July 2011 (UTC)

In Wikipedia the statements of the Institute of Medicine are taken as definitive of the scientific consensus. In highly contentious medical matters, such as the AIDS denialism article, Wikipedia uses the Institute of Medicine as THE source - I quote the AD article "The scientific community considers the evidence that HIV causes AIDS to be conclusive" (the reference given for this is the IoM).

As it stands the Vitamin D article is propounding a species of pseudoscience rather similar to AIDS denialism. The article cannot continue to allow the IoM's conclusions about vitamin D to be subjected to countervailing claims for the beneficial effect of (what the IoM has concluded are) doses of vitamin D with adverse health outcomes. Arguments to the contrary are necessarily "conspiracy theories, faulty reasoning, cherry picking, and misrepresentation of mainly outdated scientific data". It would not be allowed on the AIDs article and it should not be allowed here. The IoM is an unimpeachable source and the conclusions of its vitamin D report must be accepted. Overagainst (talk) 14:17, 17 July 2011 (UTC)

I am not arguing that the report should not have a prominent place in the article, however to just throw everything else out claiming that it is pseudoscience is really not logical. For comparison, consider Colony collapse disorder. The Environmental Protection Agency continues to insist that they see no connection between CCD and pesticides. Dozens of authorities and studies point to a connection in combination with other known stress problems. By your thinking one could go around deleting all studies that point to a pesticide/CCD connection claiming that the EPA said there was none. Is that not correct? Gandydancer (talk) 15:21, 17 July 2011 (UTC)

No, Overagainst. Equating vitamin D research which points to higher desirable intakes with AIDS denialism is kooky. I don't care how you rationalise it, they are simply completely different. -- cheers, Michael C. Price ^talk 15:32, 17 July 2011 (UTC)

Quite. But what can be equated is AIDS denialists' refusal to accept that the IoM represents the scientific consensus about AIDS and vitamin D enthusiasts' refusal to accept that the IoM represents the scientific consensus about vitamin D. Both cases have a refusal to accept the competence of the National Academies’ rigorous research process, aimed at providing objective and straightforward answers to difficult questions of national importance.

"For those at the top of their field, membership in the IOM reflects the height of professional achievement and commitment to service." Overagainst (talk) 16:08, 17 July 2011 (UTC)

Still no. AIDS denialism is pseudoscience, high dose vitamin D is science; the debate is ongoing on the latter, not on the former. -- cheers, Michael C. Price ^talk 16:25, 17 July 2011 (UTC)

The debate on AIDS denialism did not end it was, in effect, terminated by Wikipedia because benighted proponents of the minority view would not accept defeat. "Furthermore, it reflects the consensus among editors here and has been discussed several times in the past (see Talk:AIDS denialism/Archive 8#RfC on AIDS denialism). Before starting another discussion about the article title, please consult the above policy and guideline, and read through the archives to see if your concern has already been addressed." "[T]he consensus among editors here" on AIDs reflected the scientific consensus on AIDs as determined by the IoM. Among those actually qualified the scientific debate on vitamin D has been terminated by the IoM report. Holick is not the world authority on vitamin D nor is Vieth, the IoM committee is. Denialism is no more harmless about vitamin D than it is about AIDs. Overagainst (talk)

This Nature News article points to vigorous debate going on. Also, if the matter were settled, how come the head of the IOM group who has publically defended the IOM conclusions, is herself conducting a large scale double blind trial involving 5000 IU/day of vitamin D? What she has said is that at this time, you can't rigorously prove that such large doses have benefits. It's not the case that the IOM has concluded that there are no such benefits, they just insist on large scale double blind trials over many years. Other researchers don't agree that this is the way forward. Count Iblis (talk) 17:55, 17 July 2011 (UTC)

There is a rationale for taking massive amounts of vitamin D (a substance which, you should note, the body has several mechanisms to limit). But, several other supplements for there was a very good theoretical rationale (much better that for D) have been found to increase mortality in large scale trials. In some cases the excess mortality was so apparent that the trials were quickly terminated. Now many of those trials were for vitamins that unlike 'vitamin' D could not be synthesized and were in genuinely short supply in the environment (judging by the dose response). Yet they did the opposite of what everyone expected them to do, what in vitro and observational studies had led the scientists who ran the studies to expect. What these substances do to humans when ingested in in evolutionary unprecedented amounts is only just beginning to be understood. Extending life span by increasing oxidative stress. The worse case scenario is that the deleterious effects of vitamin D supplementation will be something too subtle for short term studies. Vitamin D and aging Overagainst (talk) 19:54, 17 July 2011 (UTC)

Feedback kicks in at above approx 10,000 IU/day, so I am not worried. -- cheers, Michael C. Price ^talk 20:24, 17 July 2011 (UTC)

A situation where 10,000 IU a day was being ingested every day would have been too rare for such adaptations to have evolved only hapless human guinea pigs in the modern world do that. Plasma vitamin D and mortality in older men: a community-based prospective cohort study" In contrast, high concentrations of vitamin D suppress the farnesoid X receptor that detoxifies carcinogenic bile acids (12, 20, 21), suggesting a mechanism for increased cancer risk with high vitamin D concentrations. In addition, vitamin D induces osteocalcin (26), which is expressed in pancreatic cancer cells and increases their growth, proliferation, and invasion (35). Also intriguing is the fact that the synthesis and excretion of bile acids were observed to be dramatically elevated in Klotho-deficient mice (36) that ex- hibit altered mineral homeostasis due to high vitamin D activity" Overagainst (talk) 21:16, 17 July 2011 (UTC)

Deleted cancer, cardiovascular, etc., sections

Why have these sections been deleted? Gandydancer (talk) 11:43, 15 July 2011 (UTC)

Because editor Overagainst doesn't like it, it's against his POV. Count Iblis (talk) 15:02, 15 July 2011 (UTC)

To just write an edit summary saying that the IOM says so is not going to work. Their perspective is one of many and they are currently in the minority if they are saying that there is no evidence that D is beneficial for several diseases. Unless this editor can show evidence that the IOM trumps all other sources and somehow turns the many studies that have shown benefit into some sort of odd mistakes, the disease sections should be restored. Gandydancer (talk) 16:45, 15 July 2011 (UTC)

I've restored the last stable version before the broad, sweeping changes. My hope is that through WP:BRD, discussion will begin on this rapid series of major changes to the article.  Leef5  ^{TALK | CONTRIBS} 16:56, 15 July 2011 (UTC)

I haven't gone through the edits individually, but I have to say that there is way too much reliance on primary studies, and replacing them with secondary systematic reviews (like the IOM report, or others published in the peer-reviewed medical literature) is definitely something that should be done (per WP:MEDRS, WP:PSTS, and to determine the WP:WEIGHT in the medical field). Rather than whole-sale changes to the article, a section by section approach to allow for everyone to see what changes are being made may be preferable. In this sense, I support expanding the weight and use of the IOM report (the IOM being one of the premiere medical institutions in the world, its weight has to be near the top of any discussion). Yobol (talk) 17:00, 15 July 2011 (UTC)

The problem is that the IOM report is just too controversial, See e.g. here. If people cited by the IOM are now saying that the IOM wrongly analyzed their results then, at the very least, one has to mention that there is a dispute about the IOM's conclusions. Count Iblis (talk) 17:28, 15 July 2011 (UTC)

That there is controversy when vested interests are involved is not new, for any recommendations. The IOM report is not "too" controversial to be used as a reliable source. It, however, should not be the only source for information. For instance, the Endocrine Society recommendations should likewise be included, as would any systematic review published in quality literature; if the IOM did make a mistake, it will be borne out in the systematic reviews done independently of it. Yobol (talk) 18:00, 15 July 2011 (UTC)

Yes, I agree. See here for instance from The College of Family Physicians of Canada: http://www.cfp.ca/content/57/1/16.full It is my understanding that many oncology docs now routinely check D levels and include supplements in their medications for their patients. I've been involved with medicine for many years and I've never seen new information take hold so rapidly. Gandydancer (talk) 18:13, 15 July 2011 (UTC)

I also agree. I'm not saying that we can't consider the IOM report as a reliable source, the issue is that because of the controversies surrounding this (there is strong criticism from multiple leading authors who are experts in the field), you can't use it in the way Overagainst was using it, i.e. as an authoritative report that should be awarded such a high weight that everythig else can be dismissed a priori. If this were not the case, then you could base everything on the IOM report, because what you would find in there would already be consistent with what you would find from more primary sources.

A good example where this would work is climate science. Despite the public controversy, there isn't much controversy in the scientific community. it doesn't matter if you base a Wiki article on IPCC reports or if you consider articles published in leading peer reviewed articles. Clearly, the controversy about Vitamin D is of a different nature. Count Iblis (talk) 18:25, 15 July 2011 (UTC)

I will try to see what I can drag up on the topic, but let's be clear on this point: all IOM reports carry significant weight in the medical community, and therefore they should do so on Wikipedia as well. Let's not kid ourselves that narrative reviews in relative obscure journals should get the same weight and coverage as the systematic review in the IOM report. Yobol (talk) 18:27, 15 July 2011 (UTC)

This Nature News article should be good enough. The journal Nature is not going to publish such comments if there isn't anything of substance here. Note that the essay by Oreskes about the scientific consensus on climate change, was also published in Nature, and that's also cited in the Wiki-article on global warming. Count Iblis (talk) 18:44, 15 July 2011 (UTC)

Not really. The Endocrine Society guidelines and the meta-analysis mentioned in the article should meet WP:MEDRS, as would any other meta-analysis or high quality review. News reports generally don't meet WP:MEDRS for medical claims, and in this case there does not appear to be a need to use it as we can cite the opposing meta-analysis and clinical guidelines themselves. Yobol (talk) 19:00, 15 July 2011 (UTC)

"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." NYT. So the IoM report is the most independent, authoritative and objective source there is for information on vitamin D. Here's what they found "Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake" So the sections on cancer, TB, cardiovascular health, Influenza ect ect are now established to be just plain wrong.

And here is why the article has to be changed, the IoM stated:

"Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use". Overagainst (talk) 10:41, 16 July 2011 (UTC)

IoM's statement about "adverse health outcomes" (quoted above in bold by Overagainst) seems quite strong, so I wanted to check (and quote) the actually figures they give in the report, at least to save others reading the talk page the trouble of looking it up. It pretty much reflects what is already written in this Wikipedia article. The report is available here (free registration requried). From p429-430:

Doses below 10,000 IU/day are not usually associated with toxicity, whereas doses equal to or above 50,000 IU/day for several weeks or months are frequently associated with toxic side effects including documented hypercalcemia.

DeLuca (2009) concluded that, overall, the toxicity of hypercalcemia becomes evident at vitamin D intakes above 25,000 IU/day, corresponding to a serum 25OHD level of about 500 nmol/L. Hathcock et al. (2007), following an analysis of more than 20 publications, concluded that there was no association between harm and intakes of 10,000 IU/day. Although toxic effects associated with 400 IU/day seem implausible, the diverse range of intakes and serum 25OHD levels is notable. Most reports suggest that the toxicity threshold is between 10,000 and 40,000 IU of vitamin D per day. Also, most do not identify toxicity until serum 25OHD levels of 500 to 600 nmol/L or higher are reached; frank toxicity has been associated with a serum 25OHD level of 750 nmol/L (Jones, 2008; Deluca, 2009).

It may also be referring to the studies which show a slight declines in outcomes when serum concentrations get high enough. Graphs from the report here: [4], [5]. Summary (p435):

Because the trials did not evaluate particularly high doses and as observational studies are subject to confounding, one cannot interpret conclusively whether or not this U-shaped relationship is real or causal. However, the data are clearly suggestive of a U-shaped or reverse-J-shaped risk curve between serum 25OHD level and all-cause mortality; increases in risk are suggested at thresholds in the range of 75 to 120nmol/L for the white population, with lower levels for the black population.

Anyway, would love to see more of the report incorporated into the article in future. —Pengo 11:57, 16 August 2011 (UTC)

Format of references to IoM report

As the IoM report has many pages I think the references to it should give a link to the relevant page to make it easy to verify content. Please don't standardise the refs to that report as it makes it very difficut to find the relevant page, even google only sends you to the begining of thr relevant chapter. --Overagainst (talk) 09:35, 20 July 2011 (UTC)

Tolerable Upper Intake Levels

"The Tolerable Upper Intake Level (UL) is not a recommended intake. Rather, it is intended to specify the level above which the risk for harm begins to increase, and is defined as the highest average daily intake of a nutrient that is likely to pose no risk of adverse health effects for nearly all persons in the general population. As intake increases above the UL, the potential risk for adverse effects increases. In short, the UL is a reference value intended to guide policy-makers and scientists charged with ensuring a safe food supply and protecting the health of the U.S. and Canadian populations. It applies to intakes on a chronic basis among free-living persons. Those responsible for determining the appropriate dosages of nutrients to be studied in carefully controlled experimental trials conducted in clinical or community settings have the opportunity to bring other considerations into play when deciding on the acceptable levels of nutrients that are appropriate for subjects taking part in such studies. ULs are not designed to address experimental protocols in which safety monitoring occurs." Source: Dietary Reference Intakes for Calcium and Vitamin D (2011) page 403 Overagainst (talk) 09:35, 20 July 2011 (UTC)

Are you making a particular point about something in relation to the article? —Pengo 02:43, 26 August 2011 (UTC)

New edits

Was there a consensus established before these were done I can't find where they have been discussed at all. " Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use"

I can't find the above statement by the IOM at all now. Where the article always started with the biochemistry of D. Now , suddenly there is is a 'Health effects' section right under the lede with a plethora of subsections . And the IOM is given as a reference for saying "There is no definitive benefit of health outcomes other than bone health as the evidence is not yet in.[5]" Click on the link and here is what it actually says

"Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. Although the current interest in vitamin D as a nutrient with broad and expanded benefits is understandable, it is not supported by the available evidence. The established function of vitamin D remains that of ensuring bone health, for which causal evidence across the life stages exists and has grown since the 1997 DRIs were established (IOM, 1997). The conclusion that there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health does not mean that future research will not reveal a compelling relationship between vitamin D and another health outcome. The question is open as to whether other relationships may be revealed in the future."

I think that the text does not reflect the reference and suspect that is not the only case. Previously there was a lot of direct quotation now we get rather misleading sentences. I propose reverting to the extensive use of direct quotations from the IoM. The dissenting opinions section could be considerably enlarged as proposed by Greensburger. Overagainst (talk) 15:47, 23 October 2011 (UTC)

Per WP:MEDRS we should be using review articles rather than primary research. We also tend to paraphrase sources rather than use large direct quotes (as this can create issues of copyright). The layout of the article is that outlined here WP:MEDMOS. Cheers Doc James (talk · contribs · email) 11:57, 24 October 2011 (UTC)

The Institute of Medicine's 2011 report is a tertiary source it should be given the fullest weight, I asked before using the quotes and was told that there is no problem at all as long as they are correctly attributed. The removal of primary reseach and its replacement with reviews is not what I am querying. I have given an example above of what I think is misleading wording "There is no definitive benefit of health outcomes other than bone health as the evidence is not yet in.[5]" . In the green text I don't think the IoM said that. If we use quotes from the report there is no problem of interptation. The new layout of the article puts health outcomes in an extemely prominant place above the biochemistry and implies that this is important. The IoM did not find that, they looked at all the reearch and found

"Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. Although the current interest in vitamin D as a nutrient with broad and expanded benefits is understandable, it is not supported by the available evidence. The established function of vitamin D remains that of ensuring bone health, for which causal evidence across the life stages exists and has grown since the 1997 DRIs were established (IOM, 1997). The conclusion that there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health does not mean that future research will not reveal a compelling relationship between vitamin D and another health outcome. The question is open as to whether other relationships may be revealed in the future."

Also, the lede now has this on the end of it "The health effects of vitamin D supplementation in the general population is poorly determined." That is not what the IoM says. If you disagree please cite where it does and quote from the IoM report. Overagainst (talk) 12:53, 24 October 2011 (UTC)

"The health effects of Vit D are poorly determined with little evidence for effects other than improving bone health" is supported by "there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health does not mean that future research will not reveal a compelling relationship between vitamin D and another health outcome. The question is open as to whether other relationships may be revealed in the future."Doc James (talk · contribs · email) 13:11, 24 October 2011 (UTC)

We still have the quote "An Institute of Medicine report states: "Outcomes related to cancer/neoplasms, cardiovascular disease and hypertension, diabetes and metabolic syndrome, falls and physical performance, immune functioning and autoimmune disorders, infections, neuropsychological functioning, and preeclampsia could not be linked reliably with calcium or vitamin D intake and were often conflicting."" Doc James (talk · contribs · email) 13:13, 24 October 2011 (UTC)

Can you propose a better way to summarize these conclusions? The exact quote is too wordy IMO.Doc James (talk · contribs · email) 13:13, 24 October 2011 (UTC)

Re. the lede edit to "The health effects of vitamin D supplementation in the general population is poorly determined with little evidence for effects other than improving bone health" Not bad but here is what I would put it- "An authoritative Institute of Medicine report on vitamin D came to the conclusion 'that there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health'. Some experts continue to dispute the IOM's conclusion."

I don't see a problem in quoting a couple of the the key passages of the IOM report summary We can be sure that we are getting it right when we quote them. What is the point of having 9 subsections in a 'Health effects' to say what the IoM said in a nice little paragraph. You cite Zittermann, A; Gummert, JF, Börgermann, J (2009 Nov). "Vitamin D deficiency and mortality.". Current opinion in clinical nutrition and metabolic care 12 (6): 634-9. PMID 19710612. in the mortality section. Why? It is inferior to the IoM report as a reference. I that we should return to the previous layout and text. However, as there seems to be pressure for a supplement friendly approach to be given a bigger voice and there are many experts who disagree with the IOM, there should be a much larger 'Dissenting opinions' section that is a couple of paragraphs long. Introduce the IoM as authoritative and give their conclusions first though, what they says carries a lot of weight. Any departure from the IoM line is departing with the balance of informed scientific opinion so it should be made clear that the dissenting opinions section represents a minority view among the scientific-medical community. Overagainst (talk) 17:55, 24 October 2011 (UTC)

It is a recent review article and thus I would say not inferior. Community consensus is away from using extensive quotes. We currently use one quote and place it prominently. Also we just state the facts and do not typically add "An authoritative Institute of Medicine report on vitamin D". This is the same that we do not state the journal that publishes stuff, the date it was published, or the authors. If people wish to know this stuff they can find it in the reference. No one here is recommended we not reflect the literature. Doc James (talk · contribs · email) 23:41, 24 October 2011 (UTC)

Changes

Before your underdiscussed edits de-included it there was a a small section 'Dissenting opinions on vitamin D levels' - "One school of thought maintains that human physiology is fine tuned to an intake of 4000 — 12,000 IU/day from sun exposure with concomitant serum 25-hydroxyvitamin D levels of 40 to 80 ng/mL and that this is required for optimal health. Proponents of this view include dissenting members of the panel which drafted a now superseded 1997 report on vitamin D from the Institute of Medicine. The dissenters contend that the Institute of Medicine's warning about serum concentrations above 50 ng/mL lacks biological plausibility.ref wasHeaney, Robert P., Holick, Michael F., Perspective: Why the IOM Recommendations for Vitamin D are Deficient 2011 Journal of Bone and Mineral Research, DOI 10.1002/jbmr.328

[6]" Now as far as I can see that is the latest canonical statement from those are the most well known advocates for vitamin D and dissenters from the IOM. This section needs to be put back in and greatly extended.

The current lay out has skewed the whole article we used to have an encyclopedic article that explained what vitamin D was, how it is synthesized in the body, and how it is not a vitamin in the sense that vitamin C is. Then the IoM's findings, then came a small section on dissenting opinions. look at the old sections that sat under the lede.1 Forms, :1.1 Evolution' 1.2 Production in the skin 2 Discovery , 2.1 Industrial production 2.2 Synthesis mechanism (form 3) 2.3 , Mechanism of action.

Now there is a nine subsection 'Health effects' section right under the lede. :Contents, 1 Health effects, 1.1 Mortality, 1.2 Bone health, 1.3 Cardiovascular disease, 1.4 Cancer' 1.5 Multiple sclerosis, 1.6 Allergies, 1.7 Influenza, 1.8 Deficiency, 1.9 Overdose.

That gives the impression that the most important thing about vitamin D is its potential for improving these health outcomes. And a lot of people do think that. But the best sources have to be given due weight "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." NYT. So the IoM report is the most independent, authoritative and objective source there is for information on vitamin D. Here's what they found "Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake" So there is no need for sub sections on Cancer, Cardiovascular disease, Influenza, MS ect ect, certainly not right under the lede.

The new layout is misleading. And the 'Overdose' section does not include the following inportant statment from the IoM, it stated: "Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use". Check out the Institute of Medicine. They stand above all other authorities they are the best source and must be given proper prominence and weight.Overagainst (talk) 09:02, 25 October 2011 (UTC)

We use review articles. If there are opposing positions published in different reviews yes we will present them. We present the health effects of Vit D. The "dissenting views" does not state that their is good evidence and is not a review. The new layout is not misleading. Most people care more about the health effects of a substance. Thus the layout for medication and vitamins as per WP:MEDMOS. Cochrane collaboration is by the way a a better source but I have no issue with the IOM as it AGREES basically with the other reviews. It does not deserve big quotes. Just state the conclusions. I do not understand you issue sorry. Doc James (talk · contribs · email) 11:01, 25 October 2011 (UTC)

I came back to this article after a long absence, only to find it unrecognizable. Now, it reads POV to me:

• "The quality of the evidence is, however, poor." Nowhere is this assertion reflected in the source cited.
• "Moderate to high doses may reduce cardiovascular disease risk but are of questionable clinical significance." How can a reduced disease risk not be of clinical significance? "Questionable" according to whom? One can write "the clinical significance is disputed" and quote a source. The moment qualifiers like "questionable" are used, it is POV.
• "Low vitamin D levels are associated with some cancers. When supplementation is used to treat people with prostate cancer, however, there does not appear to be a benefit. Results for a protective or harmful effect of vitamin D supplementation in other types of cancer are inconclusive." First, the writer grudgingly acknowledges the evidence of a correlation between vitamin D levels and cancer, then promptly glosses over it with a single example from a study in which it was used as a treatment and not prophylaxis. Then, to write it off completely, a single systematic review is quoted, one commissioned by the Food and Nutrition board of the IOM for the purposes of the DRI process, which is adequately cited elsewhere in the article.
• "Vitamin D fortification has been suggested to have caused a pandemic of allergic disease and an association between vitamin D supplementation in infancy and an increased risk of atopy and allergic rhinitis later in life has been found." This is too much. The bulk of the published science suggests the opposite, yet not a single example is mentioned here. The paper cited at the end of the second sentence is a historical analysis to explore a hypothesis, and not a population study. This makes me uncomfortable, since the writer seems happy to pass judgment on the quality of published research and cast vitamin D supplementation in a negative light in other parts of the article, but when it supports the writer's position, it is okay and flaws are not worth mentioning.
• "Lack of vitamin D synthesis during the winter is a possible explanation for high rates of influenza infection during winter; however, see flu season for the factors apart from vitamin D that are also hypothesized to influence rates of infection during winter. For viral infections, other implicated factors include low relative humidities produced by indoor heating and cold temperatures that favor virus spread during winter." Every potentially positive interpretation is immediately followed by a negative rebuttal. This is POV.

I could go on -- the article is full of stuff like this -- but it would take me all day. It just reads like a polemic against vitamin D supplementation, when it shouldn't read like a polemic at all.

To sum up:

1. Wikipedia's role is that of an encyclopedia -- meaning encompassing -- and not as a gatekeeper. The IOM 2011 DRI on vitamin D is rigorous, but it is neither a clinical guideline (acknowledged by its authors) nor is it the "last word." It is not Wikipedia's role to regurgitate the IOM. It is a valid source, and an important source, yes -- but it is only one source. Interested parties can read it directly. By omitting the other high-quality sources which contradict the IOM, we are doing Wikipedia readers a disservice.
2. This article is about vitamin D, not its health effects. As such, a discussion of the molecule, its biochemistry, synthesis, pharmacokinetics, and its biological role should come before a detailed discussion of its implications for health.
3. I am against a "dissenting opinions" section. That is negatively connoted and inherently POV. Just present the available evidence in the relevant sections of the article and be done with it.

The article in its current form is not balanced. Let's try to come to a consensus. --Rhombus (talk) 12:29, 25 October 2011 (UTC)

Rombus, please don't do that to the sections in Talk it confuses things. The IoM is the highest quality source. I agree with your second point this is an encyclopedic article not a medical dictionary. Third point, ok the section presenting The Heaney and Holick school of thought could be called 'Other opinions on vitamin D', but it can't be presented as countervailing. The IoM carries more weight.

Doc James, the IoM'S report was comissioned by the US government "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." NYT. So the IoM report is the most independent, authoritative and objective source there is for information on vitamin D. While the Cochrane collaboration may be a better source for you in your professional capacity it is not for editing Wikipedia. The articles are not to give medical advice in any case. I know that you have no objection to the IoM as a reference the problem is what you are say they are saying does not reflect the reference as whan you put "There is no definitive benefit of health outcomes other than bone health as the evidence is not yet in.[5]" The IoM didn't say that.Overagainst (talk) 13:27, 25 October 2011 (UTC)

Overagainst: I respectfully disagree, and that still doesn't mean that it should displace all other sources in the article. I also never wrote that this was a medical dictionary, I wrote that this is an encyclopedia article and as such should encapsulate, to the extent possible in a small space and for a lay audience, the current state of scientific understanding of vitamin D, which means that the order in which things appear in the article should be changed. I also explicitly stated I was against a separate section for "dissenting opinions", or "other opinions". I agree with Doc James we should preferentially include reviews and meta-analyses, but there are enough of those which contradict the IOM recommendations that it shouldn't be a problem to give this article the balance it deserves while maintaining a high standard.

The point is that the article reads like somebody's agenda, in other words, it reads POV. The sources have been cherry-picked and the tone is against supplementation, which doesn't reflect the body of research. The article needs to be changed. --Rhombus (talk) 14:12, 25 October 2011 (UTC)

I agree with Rhombus the IOM is just one source. I encourage others to add the conclusions of systematic reviews and meta analysis (both of which are review articles). I too am against dissenting opinion sections, we need to just state the conclusions. If it is a review in a respect journal the conslusions are typically notable. And do not need to be hidden in a POV section. Doc James (talk · contribs · email) 10:57, 26 October 2011 (UTC)

IOM's position is disputed?

If we are going to state that their position is disputed can someone provide one reliable ref from a review article showing this dispute? I will than be happy to include this. Thanks --Doc James (talk · contribs · email) 23:59, 24 October 2011 (UTC)

How is a review article going to tell us that something is disputed? A review is just that, a review. There are no reviews that say, "this assertion is disputed." A review can only say that the results are either inconclusive or suggestive of something. There is already at least one reference, the Holick and Heaney paper, in which they substantiate their reasons for disputing the IOM recommendations. That's a valid source. It's published in a peer-reviewed journal, it was written by scientists with an acknowledged body of work in the field and whose own work is quoted in the IOM DRI. It is not our job to tell readers what to think, and they cannot make up their own minds if they aren't presented all the information. --Rhombus (talk) 12:29, 25 October 2011 (UTC)

"It is not our job to tell readers what to think, and they cannot make up their own minds if they aren't presented all the information" I think the IoM can be presented as the most reliable source, its findings carry a lot of weight in medical matters. People should understand that Heaney and Hollick differ from IoM.Overagainst (talk) 12:59, 25 October 2011 (UTC)

Different reviews will come to different conclusions. Please provide one review that concludes their are health benefits other than bone health. Thanks Doc James (talk · contribs · email) 13:31, 25 October 2011 (UTC)

Do you mean systematic reviews? And what about meta-analyses? --Rhombus (talk) 15:04, 25 October 2011 (UTC)

Here is a meta-analysis evaluating total mortality in supplemented populations: http://www.ncbi.nlm.nih.gov/pubmed/17846391, and here is a systematic review of all-cause mortality: http://www2.cochrane.org/reviews/en/ab007470.html. It ought to be clear that there are unanswered questions here which are not answered by the IOM either (the authors admit as much), and if more research is needed (something about which nobody seems to disagree) then that is what needs to be clear from the Wikipedia article also. Narrative reviews have their place here too, and there are many narrative reviews which can show the reader the range of scientific opinion on this subject. --Rhombus (talk) 15:33, 25 October 2011 (UTC)

The IOM report already discusses all-cause mortality. See [page http://www.nap.edu/openbook.php?record_id=13050&page=433 433]. It does not seem to dispute the studies if I recall correctly. II | (t - c) 15:40, 25 October 2011 (UTC)

The point is that there are associations with things other than bone health, and these observations are not given adequate voice in the WP article. It can't just turn into another copy of the IOM recommendations, otherwise we can just post a link to it and close it to edits right now. One more thing. The spirit of Wikipedia is to inform. Holick and Heaney sat on the 1997 IOM panel. They have pointed out legitimate flaws in the IOM's most recent recommendations (and they aren't the only ones). They work in the field, are widely published, and are recognized specialists, so their professional credibility is not in question. These aren't even fringe opinions, they are at the centre of a legitimate scientific debate. If they take substantive issue with the recommendations, which they have done, then that merits mention in the article too, review or not. --Rhombus (talk) 15:59, 25 October 2011 (UTC)

Yes that is exactly there are ASSOCIATIONS. Associations are poor quality evidence. You notice that the first review you provide states randomized controlled trials are needed. Will add the Cochrane review.Doc James (talk · contribs · email) 10:51, 26 October 2011 (UTC)

The version of October 5th (this one: http://en.wikipedia.org/w/index.php?title=Vitamin_D&oldid=454013061) is more like what this article should look like, at least in structure.--Rhombus (talk) 16:29, 25 October 2011 (UTC)

I agree with Rombus, the format should not have been changed without discussion. Certainly not at the same time as big changes were made to the text also without discussion. OK we go back to old format and discuss the changes to the text.

Discuss the current 'Dissenting views...' section. It could be renamed the "Other opinions on Vitamin D" section and expanded. Any suggestions for the new expanded text of that section? Overagainst (talk) 19:58, 25 October 2011 (UTC)

Consensus is that we use review articles. Have moved this content lower in the article. We can continue discussion of the layout.Doc James (talk · contribs · email) 10:51, 26 October 2011 (UTC)

Review articles

There are a great number of review articles on the topic of health effects of vitamin D. There is little reason to be using primary research in this article.Doc James (talk · contribs · email) 11:22, 26 October 2011 (UTC)

Layout, weight to be given to the Institute of Medicine's report

Should we follow a similar layout to that discussed here WP:MEDMOS. Also if you look at the article caffeine which is a featured article we should be using something similar here.Doc James (talk · contribs · email) 10:53, 26 October 2011 (UTC)

Is this a medical article though? I would say it is about a vitamin, if you look at the vitamin C article it is basically similar to the long established format of this article. Biological significance , synthesis ect. The vitamin E article does follow your suggested format, but you've been editing that one!. Overagainst (talk) 13:59, 26 October 2011 (UTC)

Yes these are definitely medical articles. I have changed some of the layout back while we discuss this and asked for further input.Doc James (talk · contribs · email) 14:10, 26 October 2011 (UTC)

Changing the layout of the article at the same time as making significant changes to the text makes it very difficult to follow what changes you have made. I'm going to discuss your vitamin E page edits first to point up some problems I see with your approach. The health effects section there says 'Vitamin E has no effect on mortality, even at large doses.[9] Neither does it improve blood sugar control in an unselected group of people with diabetes mellitus[9] or decrease the risk of stroke.[10]".

The results of studies of E and mortality have been inconsistent. You cite the latest big study found no effect. But, you mentioned Cochrane as the best source of health info, maybe you are onto something there.

Antioxidant supplements: An evidence-based approach to health benefits and risks"The Cochrane approach to systemic reviews is to look at the whole evidence for the effect of an intervention[...]Our analyses showed antioxidant supplements (including vitamin E) significantly increased mortality."

It is misleading not to mention problems other than mortality Vitamin E and the Risk of Prostate Cancer concluded " Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men". That is very recent finding admittedly.Overagainst (talk) 18:17, 26 October 2011 (UTC)

About the layout, I like the latest modification you made. My main objection to the original new format was the synthesis section wasn't above above the health effects section. Let me explain why (THESE REFS ARE NOT PROPOSED FOR BEING INCLUDED IN THE ARTICLE they are relevant to part of the discussion though IMO) : Vitamin D is not a vitamin Measures of the serum levels reflect endogenous synthesis from sun exposure as well as intake from the diet and it is believed that synthesis may contribute generally to the maintenance of adequate serum concentrations. The evidence indicates that the synthesis of vitamin D from sun exposure works in a feedback loop that prevents toxicityit can be synthesized in the presence of UVB.

Interdependence between body surface area and ultraviolet B dose in vitamin D production: a randomized controlled trial"Notably, a very small UVB dose of 0·75 SED (∼8 min of sun exposure on a clear day around the summer solstice in Denmark, 56°N) and a small body surface area of 12% resulted in significant 25(OH)D production."

Vitamin D production depends on ultraviolet-B dose but not on dose rate: a randomized controlled trial. " the increase in 25(OH)D after UV-B exposure depends on the dose but not on the dose rate (1-20 min). Further, a significant increase in 25(OH)D was achieved with a very low UV-B dose."

The Pharmacology of Vitamin D Vieth himself remarks on the way humans handle vitamin D calling it "a system better designed to cope with an abundance of supply, not a lack of it" - "remarkably inefficient" -"no way to correct for deficiency".

Just to be clear here is a longer except "If one looks at the system of vitamin D metabolism in Figure 2 from the perspective of a system designed to control something, it becomes clear that this is a system better designed to cope with an abundance of supply, not a lack of it. The flow of vitamin D toward 25(OH)D is remarkably inefficient, with most bypassing it. Furthermore, there is no way to correct for deficiency of vitamin D, other than to redirect utilization of 25(OH)D toward 1,25(OH)2D production, which is the pathway most acutely important for life. That is, when supplies of vitamin D are severely restricted, its metabolism is directed only toward the maintenance of calcium homeostasis. To expand on the point that the system of vitamin D metabolism is effectively a designed for adjusting for higher inputs, not lower inputs, I offer the example of an air-conditioner system. Air conditioners are designed to compensate for excessive heat, but they are a useless way to compensate for a cold environment."

Alleles which reduce the effectiveness of the vitamin-D binding protein, and their homozygotes account for 9% and 18% of the subjects in Sinotte et al. So the idea that UV-B exposure is directly proportional to vitamin D synthesis and/or vitamin D levels is wrong IMO. Why is this important well there are beginning to be the same indications about Vitamin D that there were about antioxidants. First they are said to be beneficial, then have no effect. Then maybe some unexpected correlations with cancer are found Vitamin D Levels Appear to Be Associated With Risk of Skin Cancer, Although Relationship Is Complex.

The forgoing is just my opinion however the following quotes represent the scientific consensus and must be taken into account in the article. "Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use"." Implications and Special Concerns. You've taken that important statement completely out of the article. Why?

Your edits cite lesser authorities which suggest there might be some benefit using vague highly qualified phrasing ( 'questionable clinical significance' , 'inconclusive' , 'not known'). Is this telling people what the want to know. Your refs are not particularly recent Wang, L; Manson, JE, Song, Y, Sesso, HD (2010 Mar 2). "Systematic review: Vitamin D and calcium supplementation in prevention of cardiovascular events.". Annals of internal medicine 152 (5): 315-23. PMID 20194238.

^ Buttigliero, C; Monagheddu, C, Petroni, P, Saini, A, Dogliotti, L, Ciccone, G, Berruti, A (2011). "Prognostic role of vitamin d status and efficacy of vitamin d supplementation in cancer patients: a systematic review.". The oncologist 16 (9): 1215-27. PMID 21835895.^ a b Chung, M; Balk, EM, Brendel, M, Ip, S, Lau, J, Lee, J, Lichtenstein, A, Patel, K, Raman, G, Tatsioni, A, Terasawa, T, Trikalinos, TA (2009 Aug). "Vitamin D and calcium: a systematic review of health outcomes.". Evidence report/technology assessment (183): 1-420. PMID 20629479.

These papers have been superseded by or are inferior to the IoM report ""Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. Although the current interest in vitamin D as a nutrient with broad and expanded benefits is understandable, it is not supported by the available evidence. The established function of vitamin D remains that of ensuring bone health, for which causal evidence across the life stages exists and has grown since the 1997 DRIs were established (IOM, 1997). The conclusion that there is not sufficient evidence to establish a relationship between vitamin D and health outcomes other than bone health does not mean that future research will not reveal a compelling relationship between vitamin D and another health outcome. The question is open as to whether other relationships may be revealed in the future."sourceDietary Reference Intakes for Calcium and Vitamin D (2011)page 480 Your edit says "Vitamin D appears to have a protective effect against multiple sclerosis". That is news to the IoM.

The IoM report again Implications and Special Concerns "Of great concern recently have been the reports of widespread vitamin D deficiency in the North American population. Based on this committee's work and as discussed below, the concern is not well founded. In fact, the cut-point values used to define deficiency, or as some have suggested, “insufficiency,” have not been established systematically using data from studies of good quality. Nor have values to be used for such determinations been agreed upon by consensus within the scientific community. When higher cut-point values are used compared with those used in the past, they necessarily result in a larger proportion of the population falling below the cut-point value and thereby defined as deficient. This, in turn, leads to higher estimations of the prevalence of deficiency among the population and possibly to unnecessary intervention incorporating high-dose supplementation in the health care of individuals. National survey data suggest that the serum 25-hydroxyvitamin D (25OHD) levels in the North American population generally exceed the levels identified in this report as sufficient for bone health, underscoring the inability to conclude that there are significant levels of deficiency in the population."Overagainst (talk) 19:37, 26 October 2011 (UTC)

This is the vitamin D page ? These are recent reviews that I site. They are replacing primary sources. Describing 2010 as not particularly recent is not going to move things forwards. Guideline specifically states last 3-5 years. 2010 is 1 year ago? And than you quote a bunch of older papers that are not reviews. Also please provide PMIDs. It makes things easier to follow. Have not seen the Cochrane review of vitamin E that shows it increases mortality. If resent should be added though.--Doc James (talk · contribs · email) 00:35, 27 October 2011 (UTC)

This one PMID:18425980 --Doc James (talk · contribs · email) 00:55, 27 October 2011 (UTC)

I have no problem with the removal of primary sources and their replacement by more reliable sources, I think I already said that. My problem is that your edits are sourced to reviews rather than the IoM report. What you are doing is privileging secondary sources like reviews over the IoM report which is an extremely recent tertiary source (at the very least). The IoM report on vitamin D carries far more weight. Read the NYT on the IoM report. Overagainst (talk) 12:39, 27 October 2011 (UTC)

The NYTs carries little weight when it comes to medicine. I have no problems with the IoM especially since it agrees with the majority of review articles. We still have a large quote from them in the lead of the health effects section. This is the only direct quote in that whole section. Doc James (talk · contribs · email) 13:02, 27 October 2011 (UTC)

You have this in the article "Vitamin D appears to have a protective effect against multiple sclerosis.[30] While the initial hypothesis was based on that fact that MS occurred at high rates in the region of the world with long periods with little sunlight further supportive evidence is now available.[30] Whether vitamin D supplements during pregnancy can lessen the likelihood of the child developing MS later in life is not known.[31][32]". That is simply wrong ! Dietary Reference Intakes for Calcium and Vitamin D (2011), page 485. Quote:"An important question that will undoubtedly be asked given this committee’s report, is: Why is it that so much information about the positive effects of vitamin D on outcomes such as cancer, diabetes, and immunity is said to exist and is reported almost daily in the press, but this committee found no basis to support these causal relationships? The short answer is that a systematic examination of the evidence, using established guidelines for measuring the strength and quality of studies, revealed that the claimed benefits based on the associations of low or high intakes of vitamin D on non-skeletal health outcomes could not be supported by the studies—the evidence was inconsistent and/or conflicting or did not demonstrate causality"

IoM Report Brief.Quote: "The committee assessed more than one thousand studies and reports and listened to testimony from scientists and stakeholders before making its conclusions. It reviewed a range of health outcomes, including but not limited to cancer, cardiovascular disease and hypertension, diabetes and metabolic syndrome, falls, immune response, neuropsychological functioning, physical performance, preeclampsia, and reproductive outcomes. This thorough review found that information about the health benefits beyond bone health—benefits often reported in the media—were from studies that provided often mixed and inconclusive results and could not be considered reliable. However, a strong body of evidence from rigorous testing substantiates the importance of vitamin D and calcium in promoting bone growth and maintenance."

Reviews which you cite are small scale and do not warrant the ignoring of the IoM warning Dietary Reference Intakes for Calcium and Vitamin D (2011),Page 481. Quote:"Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use." You took this out the article . Why?

Dietary Reference Intakes for Calcium and Vitamin D (2011)Page 436 Quote:"To address the dissimilarity in results from individual large cohort studies, Stolzenberg-Solomon et al. (2010) conducted a pooled nested case–control analysis of participants from several cohorts (the ATBC Study, CLUE, the Cancer Prevention Study II Nutrition Cohort, the New York University Women’s Health Study, the PLCO Cancer Screening Trial, and the Shanghai Women’s and Men’s Health Studies) to determine associations between serum 25OHD levels pre-diagnosis and risk for incident pancreatic cancer. This large-scale pooled analysis (n = 2,285) found a statistically significant two-fold increased risk for pancreatic cancer in participants withserum 25OHD levels at or above 100 nmol/L compared with those with levels between 50 to 75 nmol. Further, the association was strongest for whites, participants in northern latitudes (> 35°N), and participants whose blood was collected in summer months. Thus, a pooled analysis of large cohort studies suggests an association for increased risk of pancreatic cancer with serum 25OHD levels greater than 100 nmol/L that is not consistently seen in analyses of individual large cohorts"

One more time "Thus, a pooled analysis of large cohort studies suggests an association for increased risk of pancreatic cancer with serum 25OHD levels greater than 100 nmol/L that is not consistently seen in analyses of individual large cohorts". Moral; use the biggest and best sources. the IoM is the biggest and the best.Overagainst (talk) 13:43, 27 October 2011 (UTC)

May be bring this up at WT:MED or WT:MEDRS Doc James (talk · contribs · email) 14:48, 27 October 2011 (UTC)

No one is trying to deny that reviews are better than primary sources and that systemic reviews are better still. I never wanted so many primary studies (I tried to take many out however I discuss major edits beforehand, there was opposition). The IoM report should be the reference except for things that it does not discuss. You are giving a collage of selected reviews and presenting the Institute of Medicine committee's report as a reference alongside reviews of far less standing. The IoM is a good enough ref on its own, it's a tertiary source (at least). Overagainst (talk) 16:11, 29 October 2011 (UTC)

There are a number of attempts by Price to remove the 10 or so reviews I have added and return the primary research. I have no issues with the IoM and think it is a great source whose conclusions should be place prominently. I guess the only thing we may disagree on is that I feel that we should summarize the IoM and add this and you wish to use quotes. I do not mind one or two quotes but feel we need to be careful not to overuse them.--Doc James (talk · contribs · email) 10:50, 31 October 2011 (UTC)