Talk:Vitamin D/Archive 1

message: ...what's this about D5 being also known as "irridated 7-dehydrositosterol"? Is that supposed to be "irradiated", perhaps? Does anyone have any clue as to what this means? Google shows "irridate" and "irridation" being used only as misspellings for "irradiate" and "irradiation", and "irridated" is only found in Wikimirrors of this very article - but giving the formal name of a substance as "irradiated (whatever)" doesn't make any sense.
Normally, I'd consider it to be just tiny gibberish-vandalism, and snip it out wholesale, but the fact that it was contributed by a registered user with a substantial edit history who continued making reasonable edits afterwards... I dunno.
I'm going to be bold and snip it out, but I left him a (slightly more detailed) message on his talk page about this, and if anyone else knows what the hell it means, could you explain? Thanks. DS 14:23, 14 September 2005 (UTC)
replies: text: Yeah, AFAIK they produce it by exposing fat bearing products to UV (i.e. irradiated with UV); and the vitamin D gets created automagically (or some such thing). That's how the fortification works. So you snipped out correct info. Congrats.WolfKeeper 12:23, 28 August 2006 (UTC)
thread_title: "Irridated"?

message: From typing in some ingredients from my calcium/vit D supplement into google, I have found:
vitamin D is more of a horomone, not a vitamin
and we make more than enough vitamin D with 20 minutes of sunshine a day, but taking supplements risks overdose (we obviously wouldnt produce it ourselves to the point of poisoning, however)
:It's not true *most* of the year in *most* of Europe for example. Between summer exposures you're running on stores which gradually deplete. The stores are large, but studies have shown that say more than 10% of people in even very sunny climates (India!) are clinically deficient at any one time. That's not good! From the figures I've seen, the risks of overdose from pills provided you don't take absolutely ridiculous numbers of pills is, quite frankly, zero. I suppose if you lived in Hawaii, went out in the midday sun for 20 minutes everyday, AND took handfulls of pills, maybe you might, eventually hit overdose. But probably skin cancer would get you first.WolfKeeper 08:39, 23 September 2005 (UTC)
thread_title: gasp

message: The following refrences show that if the Mother has sufficent amounts of Vitamin D it will be passed on the the child.
American Journal of Clinical Nutrition, Vol. 79, No. 5, 717-726, May 2004. Other references can be found by searching Sunlight Deficiency, Vitamin D, and Breastfeeding by AMMAWELL since Im new at this I will correct the info when I figure it out Smilesalot2u 01:15, 1 December 2005 (UTC)
thread_title: Correction needed in refrence to Breastfeeding and Vit D deficenciey

message: Hmm, here in America anyway, 200 I.U. equates to 50% RDA. 400 I.U. is, according to at least three of the supplements I have, in fact 100% RDA of Vitamin D. I would request the figures be corrected to correspond with reality, if no one objects. Please, folks, are my pill bottles lying or is the info on this particular Wiki article incorrect/outmoded? Is 100% RDA of Vitamin D 200 I.U. or 400 I.U.? —Preceding unsigned comment added by 70.226.168.195 (talk • contribs) 17:21, 1 February 2006
:In the UK I have pills marked: 10 micrograms, 400 IU 'EC RDA 200%'. And another marked: 7.5 micrograms 300 IU, RDA 150%WolfKeeper 02:39, 2 February 2006 (UTC)
replies: text: See  they have different RDAs for different age groups. Maybe your pills are for seniors???WolfKeeper 02:42, 2 February 2006 (UTC)
thread_title: Correction of RDA figure needed

message: The following link says that it's a steroid. WolfKeeper 20:54, 2 April 2006 (UTC)
replies: text: Many people (physicians, physiologists, university professors) make the mistake of saying that vitamin D is a steroid. This is probably because (like steroids) it is derived from cholesterol and has carbon backbone that resembles the steroid backbone. Nevertheless, all steroids have four fused rings. Vitamin D does not have four fused rings, hence it is not a steroid. --David Iberri (talk) 20:58, 2 April 2006 (UTC)

text: I've also encountered the term lysosteroid and used it in a related article (though I can't immediately recall which one) a while back. I'll see if I can dig that up when I have a moment. --David Iberri (talk) 04:46, 26 April 2006 (UTC)
replies: text: Apparently no one else has heard of lysosteroid, as googling returns a single page—the one I recently edited (Cholecalciferol). :-( So I've changed it to secosteroid, which is in very wide use. Now I'm off to complain to my biochem professor for using lysosteroid to begin with... Thanks for clearing this up, srlasky. --David Iberri (talk) 16:24, 28 April 2006 (UTC)
thread_title: Steroid?

message: I would flag this article for cleanup, but I am unsure which cleanup tag to use. At the current point in time, the article is missing critical information in various sections, and as such, is troublesome to understand. If you read through the overview, you should understand what I mean. So, yeah. If someone with a little more experience at this than me put the right cleanup tag on the article, that would be great. LuNatic 03:40, 8 June 2006 (UTC)
thread_title: Cleanup Request

message: I see that the Vitamin D analogues redirect to here. But recent developpements of analogues like the KH 1060 are considerable enought to brake the redirect, at least an article for those analogues now used as potent inhibitors of proliferation in studies. Fad (ix) 00:17, 11 July 2006 (UTC)
thread_title: Analogues like the KH 1060

message: "Melanin screens UV rays oflight so dark skin is much less efficient at generating vitamin D. It would therefore be expected that people with darker skin originally with lighter skin would suffer from deficiencies more frequently, especially if they live at higher latitudes or have an urban lifestyle, and there is much evidence that this is the case. Vitamin D deficiency and osteomalacia are known to be endemic in dark-skinned populations in the UK (particularly those from South Asia)."   
    
Isn't this the very selective pressure that favored fair skin in Europeans and Asians? If so, this should be mentioned (with appropriate source). — Philwelch t 07:57, 23 July 2006 (UTC)
replies: text: They would get a lot of vitamin D from their diet. The kinds of foods they eat has plenty.WolfKeeper 17:50, 15 September 2006 (UTC)
thread_title:  Evolution of human skin color 

message: Article says: "For example, in the United States, those living north of a line from San Francisco to Philadelphia (about 40 degrees of latitude) will not be able to produce it in significant quantities for 3 to 6 months a year."
What about those that often live around snow cover during winter? Snow reflects a high percentage of UV. Peoplesunionpro 19:10, 30 October 2006 (UTC)
thread_title:  Snow? 

message: It is a good idea to learn how it works.  WP is not short of essays on how it works.  Midgley 15:09, 3 December 2006 (UTC)
replies: text: That is certainly good advice. But to whom/what are your comments directed? If you feel that I have done something wrong, please tell me or I am likely to do it again.--DO11.10 21:35, 3 December 2006 (UTC)
thread_title:  Before working on a project 

message: in her 1954 book, Adelle Davis wrote, "Most medical textbooks say that vitamin D is formed by sunlight on the oils IN the skin although it was proved 16 years ago[A.C. Helmer and C.H. Jansen] that the oils must first be ON the skin, then exposed to ultraviolet light, and later absorbed back into the body. If persons take a bath before going into the sunshine, the oils are washed off, and no vitamin D is formed; if they do not bathe before exposure to sunshine but bathe immediately afterward, the oils are removed before the vitamin can be absorbed into the body." what is the latest information?Sanfranciscojim 21:57, 18 January 2007 (UTC)
replies: text: I came to this article looking for an answer to the question of "where specifically is Vitamin D produced?" and was unable to find that information. Is it produced by cells of the epidermis, the dermis, or both? What is the role of oils, as brought up in the above comment? Provophys 18:28, 19 January 2007 (UTC)
thread_title:  Vitamin D3 created 'in' or 'on' the skin 

message: Vitamin D is produced photochemically IN the skin from 7-dehydrocholesterol (not an "oil").
 
First off some background about the skin: It consists of two primary layers: the inner dermis, composed largely of connective tissue, and the outer thinner epidermis (see image). The thickness of the epidermis is <25 um and it contains five strata; from outer to inner they are the stratum corneum, (sometimes the lucidum), granulosum, spinosum, and basale. 
"The highest concentrations of 7-dehydrocholesterol are found in the stratum basale and stratum spinosum. Accordingly, these two layers have the greatest capability for production of previtamin D3 and vitamin D3, whereas the other layers have a lesser capability." 
Bathing removes dead skin cells from the stratum corneum, you can't "wash off" the deeper spinosum, and basale layers of the skin.
On another note "UVB affects the epidermis, and the two principal determinants [of generating Vitamin D] are the quantity (intensity) and quality (appropriate wavelength) of the UVB irradiation reaching the 7-dehydrocholesterol deep in the stratum basale and stratum spinosum."
* I will add this information to the article. And to answer the question below, you don't need sunlight to convert D2 (or D3) that you have ingested into active hormone, you just need sunlight to MAKE pre-vitamin D3 from 7-dehydrocholesterol, which is converted to active hormone, only when the vitamin is required, in the kidney.
*The following article is quoted and referenced here and provides more details: Sunlight, season, skin pigmentation, vitamin D, and 25-hydroxyvitamin D:integral components of the vitamin D endocrine system Anthony W Norman 1998. (Also, stop reading medical texts from 1954 :))
Hope this helps---DO11.10 19:41, 19 January 2007 (UTC)
thread_title: Answers

message: does one still need to have UV exposure when taking D2 for the correct metabolic process to proceed?Sanfranciscojim 22:06, 18 January 2007 (UTC)
thread_title:  Vitamin D2 vs D3 

message: I added a wikilink to the ligand term in the Role in immunomodulation section, but I'm not absolutely positive that it's the correct term.  Could someone knoweldgable about the subject make sure it is correct please?  Thanks.WLU 18:25, 23 January 2007 (UTC)
replies: text: That is the right term- thanks!--DO11.10 21:16, 23 January 2007 (UTC)
thread_title:  Ligand 

message: Hi,
This is my first time ever posting to wikipidia so I'm not sure how this works.  I hope I've come to the correct place.  
In the Overdose section the third sentence reads:
Although normal food and pill vitamin D concentration levels are too low to be toxic, because of the high vitamin A content in cod-liver oil it is possible to reach poisonous levels, if taken in multiples of the normal dose.
I am confused by the mention of vitamin A.  Either the mention of vitamin A is a typo or (more likely – given my lack of medical knowledge)  somehow vitamin A increases the toxicity of vitamin D.  If the latter case it true, perhaps, one of the contributors could put in a sentence or two about how high levels of vitamin A can cause one "to reach poisonous levels" of vitamin D.
Thanks (and if I'm in the wrong place please let me know)
-Kevin —The preceding unsigned comment was added by 208.237.178.229 (talk) 16:10, 31 January 2007 (UTC)
replies: text: This is the right place. Yes that was a typo, I think that sentence was directly copied from the vitamin A article or something. I have changed it to vitamin "D". Good catch.--DO11.10 18:50, 31 January 2007 (UTC)
thread_title:  Possible typo in Overdose  

message: The following addition is dubious.
The toxicity limit on Vitamin D is often questioned. Reinhold Vieth, a published vitamin D researcher, recommends 4000IU per day as an ideal amount for good health and points out that only levels above 95μg/day (3800 IU/day) may cause hypercalcemia.Vieth, Rheinhold, [http://www.insinc.com/onlinetv/directms13oct2005/softvnetplayer.htm 
Prospects for Vitamin D Nutrition], Friday, October 21, 2005 Also, no normal human being (i.e not suffering from vitamin D hypersensitivy or other ilnesses) has ever contracted Vitamin D toxicity, despite the fact that a fair-skinned person who exposes themselves to the sun for 20 minutes can produce up to 20,000 IU per day.''
*The first citation is quite poor, there must be a peer reviewed source out there. 
*"Normal human being" is inappropriate, and pejorative. 
*The second sentence will require citation for the amount produced. But, really, so what? People don't get vitamin D toxicity from the sun, toxicity comes from supplements or industrial accidents this was already stated above in the same passage.--DO11.10 18:22, 12 February 2007 (UTC)
thread_title:  Citation tag explained 

message: Hemp seed appears to have a lot of Vitamin D.  This should probably be added along with shiitake mushrooms as a vegan source.  But is it D2 or D3?  Badagnani 19:22, 14 March 2007 (UTC)
thread_title:  Hemp seed 

message: Note: Parathyroid hormone stimulates the activation of vitD so that osteocytes become activates and Ca concentration is increased.  —Preceding unsigned comment added by 134.36.123.158 (talk) 17:18, 28 April 2008 (UTC)
thread_title: Note

message: Legacy recommendations call for people from age 50 to 69 to get 400 international units (IUs) of vitamin D per day and for those over age 70 to get 600 IUs. Many researchers, however, suggest that 1000 to 4000 IUs may be needed.  Brian Pearson 04:52, 23 April 2007 (UTC)
thread_title:  For some, diet may not be enough for Vitamin D 

message: Following this sentence These wavelengths are present in sunlight at sea level when the sun is more than 45° above the horizon, or when the UV index is greater than 3. it might useful to add that the required solar elevation occurs daily within the tropics, daily during the spring and summer seasons at mid latitudes, and almost never within the arctic circles.  The point to make apparent is that for many countries there is an annual cycle of boom and bust, which is a huge factor in the health issues associated with vit D.  
Suggestion: 
:At the latitude of Seattle, Montreal, Venice, and Christchurch NZ the sun rises to this elevation during spring and summer, but not during fall and winter, resulting in annual vitamin D cycles. 
I picked well-known, longitudinally distant cities at 45 degree latitude; there are few such cities in the southern hemisphere apart from Christchurch.  See List of cities by latitude. 
From http://www.theglobeandmail.com/servlet/story/RTGAM.20070428.wxvitamin28/BNStory/specialScienceandHealth/home
:For the rest of the population, vitamin D levels tend to be lower, and crash in winter. In testing office workers in Toronto in winter, Dr. Vieth found the average was only about 40 nanomoles/L, or about one-quarter to one-third of what humans would have in the wild.  
MaxEnt 14:30, 28 April 2007 (UTC)
thread_title: Latitude factor

message: This is a shocking number, and hard to believe on face value.  Twice the effect as compared to smoking.  I did a little arithmetic on that.  
http://www.bccancer.bc.ca/HPI/CancerStatistics/FF/AgeStan/Inc/default.htm
Cancer rates for women in BC run about 330/10,000 per year.  1200 women broken into two equal groups and followed for four years gives you 2400 women-years per group.  At a rate of 330/10,000 with a 60% reduction in the non-control group gets you incidence rates of 7 and 2.8.  How does one measure 2.8 cancers?  Quite possibly, the actual numbers were 10 and 4.  14 total cancers in 4800 women-years is a rate of 291/100,000, which is quite realistic.  If it breaks down 7 and 7, you have no result.  Standard deviation sqrt(14) = 3.7.  It looks to me like both sides of the study are within one standard deviation of a possible mean.  I don't know off the cuff how to compute the null hypothesis properly, but it's certainly large enough to cast doubt. MaxEnt 16:24, 28 April 2007 (UTC)
replies: text: I thought about this some more.  My calculation above assumed age-standardized rates.  For a study of this size, it's extremely hard to achieve statistical significance with a mean rate this low.  Almost certainly the population was biased toward older age groups to achieve a higher mean rate.  Women over the age of 65 have a mean rate four times as high.  http://www.bccancer.bc.ca/HPI/CancerStatistics/FF/Rates/incidence.htm  If the mean rate for the age-skewed study group was 800/100,000, then 20 cancers are expected in the control group, and the 8 observed cancers in the experimental group (-60%) comes out 2.7 deviations below the mean.  The study is much stronger if the experimental population was tilted toward advanced age.  MaxEnt 17:47, 28 April 2007 (UTC)
replies: text: I would like to know if there has been less tanning recently than in years past when people seemed to believe tanned people were nicer looking and possibly more "healthful" looking. Brian Pearson 03:03, 6 May 2007 (UTC)

text: I am confused. The article history shows that the results of this study were (first) added to the article by you. Are you disputing information that you - yourself - added?--DO11.10 00:28, 30 April 2007 (UTC)
replies: text: I don't think he is disputing it so much as he is wondering aloud how a reduction of that magnitude is possible. WatchAndObserve 14:56, 6 May 2007 (UTC)
replies: text: Cathelidicin also seems to be directly anti-carcinogenic though I don't know whether this is due to an anti-pathogenic effect, which i8t has, or some other cause. Though I'd be careful with some of these studies on Vit-D "deficiency". People with low 25-D are likely to be so because of either existing infection or liver or kidney problems, or overconversion to 1,25D. Most studies fail to account for these possibilities. --76.166.24.76 (talk) 03:20, 2 January 2009 (UTC)
thread_title: 60% cancer reduction

message: I am taking issue with the following statement:
One recent consensus concluded that for optimal prevention of osteoporotic fracture the blood calcidiol concentration should be higher than 30 ng/mL (US units), which is equal to 75 nmol/L (System International units).
The reference given is http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp, but I don't see this information anywhere on the page.  If nobody objects, I will be removing the reference from this statement and adding a 'citation needed' tag.WatchAndObserve 14:59, 29 April 2007 (UTC)
replies: text: I have changed the citation.--DO11.10 00:28, 30 April 2007 (UTC)
thread_title: Reference questioned

message: Please note that the article entitled "Vitamin D" includes a citation by one Martin Mittlestadt. See citation no. 39.  The name is incorrect. The correct form of his name is Martin Mittelstaedt. Cf. 
http://www.theglobeandmail.com/servlet/story/RTGAM.20070428.wxvitamin28/BNStory/specialScienceandHealth/home
Boytinck 17:45, 1 July 2007 (UTC)
replies: text: Done--DO11.10 02:29, 3 July 2007 (UTC)
thread_title:  Vitamin D; spelling of Mittelstaedt, Martin 

message: I'd like to add a video in which Dr. DeLuca from University of Wisconsin discusses the history of the discovery and applications of Vitamin D. The link is http://www.researchchannel.org/prog/displayevent.aspx?rID=3751&fID=345 (this does not automatically open the video). Please let me know what you think. (ResearchChannel 19:42, 17 July 2007 (UTC)
replies: text: While the content of this video is great, (from what I saw... the history part was fascinating) the streaming quality was –well– bad. I tried the video in both WMP and Quicktime. In WMP the video paused to buffer seven or eight time in the first minute, and didn't get any better when I skipped around. The Quicktime version was better, no buffering issues, but when I tried to skip I lost the sound(?). Given that the video is 1 hour 18 minutes long both issues will probably hinder it's usefulness here. Granted it could be my settings or something (probably not my connection speed though, I am running at over 2,000 kbps). If it is possible to address these issues, I think that the video is certainly relevant and I would like to add a link. --DO11.10 18:30, 20 July 2007 (UTC)
thread_title:  External Link Video Add 

message: I cannot find this information on the milk page: it is my understanding that Vitamin D is fat-soluble. Does this mean that skim milk cannot be fortified with it? Staypuft9 16:07, 20 August 2007 (UTC)
replies: text: My skimmed milk claims it is fortified with D. --Michael C. Price talk 16:29, 15 November 2007 (UTC)

text: I'm pretty sure most skim milk has at least some fat Nil Einne (talk) 12:22, 27 December 2007 (UTC)
replies: text: I read that whole milk contains about 3% fat and skim milk contains about 0.5% fat, but I don't recall where I read it. Greensburger (talk) 17:35, 27 December 2007 (UTC)
thread_title:  Vitamin D in milk 

message: In a meta-analysis of 18 studies, vitamin D (mean dose 528 IU) reduced the mortality risk by 7%. Exact mechanisms remain unclear, and more trials are needed. URL JFW | T@lk 21:43, 10 September 2007 (UTC)
thread_title:  Mortality benefit 

message: The article currently states, "Vitamin D regulates the calcium and phosphorus levels in the blood by promoting their absorption from food in the intestines, and by promoting re-absorption of calcium in the kidneys."
It is my understanding that parathyroid hormone (PTH) promotes the re-absorption of calcium in the kidneys.  Is it is actually vitamin D that does this, or a combination of vitamin D and PTH?  If vitamin D is involved, what is the process?
An answer to this question, with a reference to an online medical research or review article, would be appreciated?
Leeirons (talk) 16:42, 11 December 2007 (UTC)
replies: text: The reference given (The Merck Manual) states the vitamin D and it metabolites "Enhance Ca reabsorption by the [kidney] tubules". "The conversion to 1,25(OH)2D [active vitamin D hormone] is regulated by its own concentration, parathyroid hormone (PTH), and serum concentrations of Ca and phosphate."--DO11.10 (talk) 18:43, 11 December 2007 (UTC)
thread_title:  Does vitamin D actually promote reabsorption of calcium in kidneys? 

message: Hibernation
"hibernating bears wake up when given vitamin D" looking for confirmation or reliable source/citation for this.
http://www.arthritistrust.org/Articles/Sunshine%20Deficiency%20Diseases/index.htm
hibernating bears also have elevated parathyroid hormone which protects against bone loss. 
http://jeb.biologists.org/cgi/content/abstract/209/9/1630
Morbidly obese humans have decreased vitamin D and elevated PTH. (before and after gastric bypass, so surgery did not cause it). Vitamin D suggested as an additional factor.
http://www.springerlink.com/content/c3387p46381j6113/
Anecdotal evidence for euphoric states/elevated/sleep disturbance mood during the summer months at high latitudes.
Vitamin D depletion and correlation with activity/anxiety/nervousness as adaptive behavior - preparation for winter? (might explain some angry bears in the fall and spring!). Looking for citations
 
Tanning and UV exposure:
would be good to reference the 20,000 IU of vitamin produced by 20 minutes of natural UV exposure and whether tanning beds produce this same effect.  The human body's vitamin D production is naturally limited to about 20,000 IU/day. After the precursor is used up, no more vitamin D is produced. www.vitamindcouncil.com
216.18.16.98 (talk) 20:21, 17 December 2007 (UTC)
thread_title:  Obesity, hibernation in other mammals. Cross reference to tanning/tanorexia/tanning addiction 

message: As not a specialist around this field, first, I thought "UV" good for vitaminD could include UVA (blacklight) -- as for tanning. I thought, rotating the body-portions exposed to light, would lessen the skin-age problems associated with (also) UVA.
That UVB is necessary (as this wikipedia article is informing), that heightens the risk of that in-house-D-light plan of mine. Truly? Or, may we keep that in check, such that with UVB lights, could people fortify their bones with light at home?  (If sun is good, how is a handheld UVB-light not? Why not talking about that?)
The rotating of the exposure is again a tool to lessen the strain on the skin-spot, probably (unless the skin gets used to that in time). cf. How diabethic people rotate insuline-injections, not to inject at a single spot all the time. What guidelines for amounts of such locally-applying UVB -- in turns? That would fortify this vitD article, I think.
--FerzenR (talk) 09:44, 8 January 2008 (UTC)
thread_title:  are there safety studies/estimates for rotating a UVB light (around the body, locally-applying, in turns) ? 

message: The text summarizing the action of UVB in respect to wavelength segment is far too ambiguous, carries a factual error,  and is not representative of actual process involved.  It has been understood from experimentation and the resultant literature since the 1980s that optimal synthesis of 7-DHC to preD3 occurs in a relatively narrow band, from 295-300nm, with maximum conversion at 297nm.  This segment is often referred to as D-UV.  
As such, I am making necessary corrections to the text, and including corroborating references.
Pragmatist (talk) 17:36, 7 February 2008 (UTC)
thread_title:  Spectral sensitivity and synthesis of previtamin D3 

message: "fortified milk typically provides 100 IU per glass" Is that a big glass or a small glass? perhaps we can create the Big Glass and the Small Glass as a units of measurement specifically for the US, so that we can talk about 2.735642367 Big Glasses of something.  80.2.199.213 (talk) 16:32, 8 March 2008 (UTC)
replies: text: Checking the source I see that they meant a one pint glass. --Michael C. Price talk 17:49, 8 March 2008 (UTC)

text: Milk contains 100 U of vitamin D per 8 oz, (240 ml).  It is of interest that soy milk contains D2 and cow mild D3, at 100 IU per 8 oz serving.  With D2 having less activity, and D2 assaying similarly to D3 in the usual 25 OH-D assay there is much potential for blood assays to misidentify individuals on Soy milk as having adequate Vitamin D levels.  I usually get a 25-OH D level by LC/MS/MS to fractionate the D2 and D3.  Kd4ttc (talk) 03:48, 28 January 2009 (UTC)
thread_title:  "Per glass" 

message: There is evidence that vitamin helps hearts, and other evidence that it may raise cholesterol and harm hearts.  
The reason may be that there is a window of ideal vitamin D nourishment, and levels below the lower threshold cause coronary problems while levels above the higher threshold tend to raise cholesterol (and harm hearts).  
It may be that the cancer-preventing benefits of vitamin D may be maximized, while the possible heart-harming effects are minimized, if one takes three times the chosen dose every third day, with no vitamin D supplementation on the two days in-between.  
Perhaps the title to this section lacks nuance, and the section should be re-titled to reflect that the relationship between vitamin D intake and cardiac events may be a bit more complicated than a straight-line correlation between so that higher and higher supplement levels must always result in lower and lower rates of cardiac events.  —Preceding unsigned comment added by 68.166.202.4 (talk) 01:51, 21 March 2008 (UTC)
replies: text: Or it could be the opposite. High cholesterol leads to more hormone D3 (the more accurate term for vitamin D, since it's not really a vitamin but is produced in-vivo). Inflammation triggers toll-like receptors which upregulate CYP27B1. CYP27B1 converts 25D (which is usually what is measured to determine deficiency) into the active form 1,25D creating an apparent deficiency, however 1,25D3 would be abundant in such a state. Higher 1,25D3 leads to increased activation of the hormone D receptor in individuals with functional hormone D receptors leading to increased blood levels of calcium. Activation of the hormone D receptor also stimulates demineralization of bone (Calcium from bones goes into the blood stream.) In the absence of sufficient Vitamin K (either from a lack in the diet or from a number of drugs, particularly blood thinners, which inhibit Vitamin K metabolism), this leads to calcification of soft tissue rather than bone mineralization, arteriosclerosis and heart disease in the long term. This seems accurate to me and I could source any step in the chain. The sequence as a whole, however, may constitute original research. There's good evidence, for instance that statins, which prevent cholesterol synthesis, actually help with osteoporosis.  This is not what you'd expect if Vitamin D were the cure for osteoporosis. --Ryan Wise (talk) 05:55, 26 August 2008 (UTC)
thread_title: Role in coronary disease prevention?

message: Sorry -- added, but can't seem to format.68.166.202.4 (talk) 02:31, 21 March 2008 (UTC)
thread_title:  Footnotes format in coronary disease prevention need fixing 

message: There was a study published which I think successfully explains why the flu is a winter illness, and why vitamin D supplementation in the winter months may help fend off the flu. I've included a link to the paper's abstract below (google scholar):
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=529704
It would be great to get information from this paper into the wiki article on Vitamin D, and maybe also on the influenza page....  —Preceding unsigned comment added by L8daRa (talk • contribs) 18:12, 17 April 2008 (UTC)
thread_title: Add section about benefits of vitamin D and fending off and/or fighting influenza

message: # Vitamin D Fact Sheet from the U.S.National Institutes of Health  —Preceding unsigned comment added by 68.165.11.156 (talk) 04:03, 19 May 2008 (UTC)
thread_title: External links should start with the superb Vitamin D Fact Sheet from the U.S.National Institutes of Health 

message: http://news.yahoo.com/s/ap/20080516/ap_on_he_me/vitamin_d_breast_cancer;_ylt=A0WTUdfM9TBIGHAB0Q4R.3QA
:page not found --Ryan Wise (talk) 13:17, 2 June 2008 (UTC)
thread_title: Too much D, like too little, a risk factor for breast cancer

message: "According to the researchers, due to rapid skeletal growth, children and adolescents are more likely to be vitamin D deficient, and are far less likely to reach vitamin D levels that doctors would consider toxic."  Brian Pearson (talk) 22:55, 27 June 2008 (UTC)
replies: text: "Warfarin-induced artery calcification is accelerated by growth and vitamin D."--Ryan Wise (talk) 04:18, 26 August 2008 (UTC)
thread_title: Children can tolerate more Vitamin D, though optimum is debateable

message: I think there's some cause to question whether Vitamin D supplementation is helpful. 
There are some who say that low levels of 25 D are caused by infection which causes 25 D to be converted to 1, 25 D in unhealthy amounts due to disregulation of the vitamin D receptor. Testing for 25 D showed lower levels in unhealthy people, but I can't find any controlled study demonstrating that D3 supplementation alone increased bone density superior to either calcium supplementation + D3 or calcium alone. 
Likewise, it's anti-cancer effects only appear in short term trials and are comparable with other immunosuppressives such as prednisone in this regard. Benefits disappear with long term use.
see
http://bacteriality.com/2007/09/15/vitamind/
and
http://trevormarshall.com/BioEssays-Feb08-Marshall-Preprint.pdf  —Preceding unsigned comment added by 63.166.226.83 (talk) 18:38, 4 June 2008 (UTC)
replies: text: In the article, it said, "In one study, hypercalciuria and bone loss occurred in four patients with documented vitamin D toxicity." Could 25,000 IU have actually caused some demineralization? Brian Pearson (talk) 03:42, 3 June 2008 (UTC)
replies: text: It should, yes. Especially in such high doses. --Ryan Wise (talk) 18:21, 13 June 2008 (UTC)
thread_title: Is D3 supplementation helpful?

message: It  mentions COMA -- Committee on Medical Aspects of Food and Nutrition Policy (UK; disbanded in 2000). It had recommended, "...For individuals confined indoors, pregnant and lactating women, an intake of 0.01 mg/day..." I think this is a bit outdated. It's my understanding 2000 IU is more appropriate. Brian Pearson (talk) 22:54, 27 June 2008 (UTC)
thread_title: Re Reference #54

message: See http://www.thelancet.com/journals/lancet/article/PIIS014067360668971X/abstract
http://sci.tech-archive.net/Archive/sci.med.nutrition/2007-09/msg00331.html Incidently, took daily 400iu pill last winter - no colds at all. 80.2.194.251 (talk) 15:53, 28 June 2008 (UTC)
thread_title: An explaination for the [[French paradox]]

message: I suggest moving the part in the lede explaining the functions of vitamin D into a new, separate section, as are done with most other vitamin articles. Afterwards, we can start gradually incorporating infos about vitamin D's functions that were formerly scattered in the article or left unmentioned. If no one objects...... Keith Galveston (talk) 09:11, 29 June 2008 (UTC)
thread_title:  A new separate section on "function" 

message: Considering all the talk of increasing vitamin D levels, this study entitled Calcium and vitamin D intakes are positively associated with brain lesions in depressed and non-depressed elders seems intriguing. It is cited by Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial, which is cited by an editorial called Mixed messages, as well as a [Assessing benefits and risks of hormone therapy in 2008:
New evidence, especially with regard to the heart review of hormone therapy in women]. II | (t - c) 02:51, 16 July 2008 (UTC)
replies: text: Yes, the abstract was vague about dosage. Wonder if the article has more detail. Brian Pearson (talk) 05:44, 22 July 2008 (UTC)

text: Vitamin D only puts calcium into the blood. Without adequate vitamin K extra Vitamin D can lead to calcification of soft tissues. Menaquinone (K2) seems to be the best form of K to prevent this. Also, blood thinners (warfarin, aspirin) often interefere with K metabolism leading to increased calcification. --Ryan Wise (talk) 04:15, 26 August 2008 (UTC)
thread_title:  Brain lesions and vitamin D 

message: Here is my edit
The article says that the findings were experimental.  Prior to my edit, the wikipedia article sounds as if I go to the store today and buy them, that I'm buying the kind that were exposed to UVB ionizing radiation (specifically 295-297 nanometer).  Mushrooms do not deserve to be on the list, but I'll let it slide since I dont want to offend the person who put in the work and cited it.  Is a very interesting article you can read it here.  
Also there seems to be misunderstanding about how the IU system works.  IU measures effects of a serving, not the measurement of how many vitamins are in it.  This is the reason why vitamin pills can't list serving size of 100% daily serving (measured in IU's) of a vitamin, unless it is absorbed and is equivalent to the biological benefits of eating a healthy diet which also yields those same 100% IU benefits for whatever vitamin in question.  The explanation over at the IU page is very biased and makes it look like doctors/scientists are dumb since measurements are not easily understood, and actually more misunderstood.  
If someone puts back mushrooms into the list and lets readers make the assumption that mushrooms have a full serving of vitamin D, please leave a message on my talk page, or try to work it out with them, as they may not have read the discussion page.  Thanks Sentriclecub (talk) 21:02, 5 August 2008 (UTC)
replies: text:  Perhaps something like this should be included:  Faro0485 (talk) 05:40, 27 September 2008 (UTC)
thread_title:  Can someone watch this page?  Dont let the misleading part about mushrooms get reverted. 

message: I have some concerns regarding one anon user's edits to this article: http://en.wikipedia.org/wiki/Special:Contributions/76.113.156.31 Could someone take a look at them to see if they're alright? Thanks. --Phenylalanine (talk) 03:41, 5 September 2008 (UTC)
thread_title:  Request 

message: I believe the citation given for depression is inappropriate - I've given my reasons over at Talk:Hypovitaminosis D, which uses the same citation. --144.53.226.17 (talk) 00:16, 6 January 2009 (UTC)
thread_title:  Depression? 

message: Mushrooms are not discussed in this article.  Monterey Mushrooms, in California, is selling UV treated mushrooms which purport to have 869 percent the daily value of vitamin D.  This is currently being studied by the FDA 
American Journal of Clinical Nutrition, Vol. 69, No. 1, 95-98, January 1999 reports on a study of the bioavailabily of Vitamin D in some Finish mushrooms, and found that they were a real source of Vitamin D.
Various mushrooms are listed as a good source of vitamin D on other websites, and it seems like this is a real omission from your article.
67.183.202.117 (talk) 19:24, 6 January 2009 (UTC)
replies: text: You're wrong. See the subsection on biochemistry of D. You didn't read the whole article! SBHarris 04:11, 28 January 2009 (UTC)
thread_title:  Mushrooms 

message: The reference to the PDR on the web went to the consumer PDR site.  There was no support there for safety at a dosage of up to 10000 units per day.—Preceding unsigned comment added by User:Kd4ttc (talk • contribs)  
:The book does. I've removed the link, it was just for convenience anyway.--DO11.10 (talk) 06:50, 28 January 2009 (UTC)
thread_title:  Reference to PDR 

message: VITAMIN D : The power of the sun, sometimes.
Here is an important lead that hopefully someone can follow up on...
I had the opportunity to ask a Dr. Lower, whose office is located on Bay Street in Thunder Bay 
While sunlight is an important source of Vitamin D, we should understand that being in the Northern Hemisphere, (people above the 40th parellel) during the winter the Sun's usefulness is severely  restricted by the angle of the earth which increases the filtering process of the essential light rays.   The earths atmosphere renders most natural light exposure during the winter months useless (the same effect as sunlight rays being filtered through glass).
The conclusion he suggested that most all people living in the Northern Hemisphere take a Vitamin D3 supplement, or the old fashioned treatment, Cod Liver Oil
--Caesar J.B. Squitti: Son of Maryann Rosso and Arthur Natale Squitti (talk) 20:35, 20 February 2009 (UTC)
thread_title:  VITAMIN D : The power of the sun, sometimes.