Talk:Vitamin C/Archive 2

This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Archive 3

Ester C (non acidic)

Why is ther no mention of Ester C or non acidic Vit C? It is very prominent, just do a google search or check your local pharamacy.

It looks like you are referring to ascorbyl palmitate (Ester C). It's a distinct compound from ascorbate, though chemically very similar (and perhaps biologically so, although relevant citations would have to be made to demonstrate this). It might merit its own article since it is distinct from Vitamin C, but it would not be unreasonable to add a section to this article discussing Ester C with references. Ante lan ^talk 04:56, 18 April 2007 (UTC)

I've created/modified the redirects Ester C and Ester-C, to redirect to ascorbyl palmitate, as well as editing all the forms of vitamin C into this article. — Jack · talk · 01:14, Thursday, 19 April 2007

Thanks. Nice work! Ante lan ^talk 20:03, 19 April 2007 (UTC)

Ester C isn't ascorbyl palmitate, it's some variety of Calcium Ascorbate. Pocopocopocopoco 15:27, 22 July 2007 (UTC)

Along this line, I would like to see a discussion about what properties are needed to synthesis collagen in the body. For instance, some think that you need molecularly natural vitamin C to achieve this effectively. What is the difference in synthetic Vitamin C, Ester C, and GNLD Vitamin C. GNLD (made and marketed by GNLD - www.gnld.com) is made wholly from natural fruits and vegetables and contains properties found in a whole orange for which the manufacture (GNLD) call it a molecularly natural vitamin C and state that it works better in the body than "synthetic" vitamin C. Some claim there is no difference in Vitamin C. I do not believe this to be true. Having taken the cheap Vitamin C found in health food stores and the GNLD Vitamin C products, I have seen, in myself a huge difference between the products. The relevance to this discussion on the TYPE of Vitamin C is in regards to a year long mini study I did with 7 puppies using GNLD Vitamin C with some of the puppies to reduce the risk of hip dysplasia. The study had astounding results, but was only a very small one. When studies are done regarding Vitamin C, I would like to know what kind of Vitamin C was used in the study. The GNLD Neo-C Vitamin C contains the following properties: Ascorbic Acid (Vitamin C) 230 mg Neo-Plex Concentrate:

Citrus sinensus fruit juice dry 90 mg
Citrus sinensis fruit peri dry 620 mg
Citrus bioflavonoids extract (orange) 410 mg
Malpignia punicifolia (Acerola cherry)Extract – EQIV to fresh fruit 8 mg
Rosa canina (Rose hips) fruit powder 2 mg
Rutin 5 mg
Hesperidin 5 mg
Citrus Bioflavonoids extract (lemon) 5 mg

How does this differ from synthetic Vitamin C that is not made wholly from fruits and vegetables and does not contain all the properties relative to a natural orange? I keep hearing that synthetic Vitamin C contains petroleum. Can we have a discussion on this please. What other nasty little things might be lurking in "Vitamin C." Syguthsy (talk) 04:23, 1 February 2009 (UTC)

Please post a link to the study you have done, or a link to a scanned upload of your studies papers. 120.16.166.62 (talk) 02:33, 14 July 2010 (UTC)

Red Links

Treatise on the Scurvy - do we usually give published works their own article? I was thinking of just redirecting it to the lind guy as that article talks about that paper sufficiently anyway..
Axel Holst - Created Article
Theodor Frølich - Very difficult to find info on this guy, all i know when hes born and died and that hes a paediatrician(sp?), then the rest goes on about the discovery he made along with the axel guy... i checked norwegian wiki and theres an article on axel guy but nothing on this guy.... so dunno what should we do about this? Someone might have to dive into a lib book about 18/19th centuary norwegian paediatricians lol..if there is such a book...
Joseph L Svirbely - from what i understand Albert Szent-Györgyi was the guy who actually discovered Ascorbic acid (just thought of it as a diff name), in 1927 and then later concluded that it was ascorbic acid with the Joseph guy... it would explain why the joseph guy didnt win the nobel prize.. However he aint a nobody as he has written 4 journal articles back in the 30's, 3 by himself and one as a group to do about ozone... but no actual info about him... So yeah another dilema..
J.J. Burns - unable to find what his first name was so impossible to find..... his journal articles just list his name as in the article and the info stated is exactly what is said in ascorbic acid..... so Again another dilemma... i guess no one actually sat down and said, ok let's get some info from these guys...
Takeda ... dunno why this was shown in the article as BASF/Takeda .... that implies they are the same yes? Or the most important distributors.. found an article about Takeda Pharmaceutical Company.... whos betting that they are the same? If you think so make a redirect.

Thanks for ur attention. petze 14:47, 20 April 2007 (UTC)

Anonywiki

User:Anonywiki continues making edits containing false information about the tolerable upper limit of Vitamin C, claiming it is 5,000mg/day. He then sources these edits to this page, which does not contain any information directly but links to these articles that support the 2,000mg/day TUL, not the 5,000mg/day value that he is plastering across this page. He continued after I explained this to him. For this and other changes that exemplify a pattern of troubling edits, I have created a RfC about Anonywiki. Ante lan ^talk 04:02, 18 June 2007 (UTC) I have no idea why trolls like User:Antelan exist on wikipedia. I simply changed the 2000mg to 5000mg as 5000mg was the one it was stated as being on the page entitled tolerable upper limits and there were no sources cited for the 2000mg one. Then I received this: Welcome to Wikipedia. We invite everyone to contribute constructively to our encyclopedia. At least one of your recent edits, such as the one you made to Vitamin C, was not constructive and has been reverted or removed. Please use the sandbox for any test edits you would like to make, and take a look at the welcome page to learn more about contributing to this encyclopedia. Thank you. Ante lan ^talk 01:26, 18 June 2007 (UTC)

on my discussion page. Why do trolls always produce this bull??? I don't mind them putting it if it's an obviously bad edit, but considering the 5000mg was the one on the tolerable upper limit page specially dealing with upper limits, I changed it to that. Now after searching through the website that the page links to, you have found it as being 2000mg. Did we really have to have a big show about it? Nobody actually believes you can't go above 2grams of vitamin C in today's world, and you would definitely find sources having a tolerable upper limit of 5grams or maybe 20grams. Anonywiki 20:12, 18 June 2007 (UTC)

Please see WP:OR and WP:CIVILITY. I encourage other editors to look through the diffs to see what happened. Ante lan ^talk 20:33, 18 June 2007 (UTC)

Also, the non-Wikipedia source that you cited listed the value at 2,000. Whether that's willfully misleading or just ignorant is not my judgment to make. Ante lan ^talk 20:35, 18 June 2007 (UTC)

Photo

This is the same picture as Absorbic acid. Something seriously wrong somewhere! Can anyone help to identify what the picture is of? Thanks. --THobern 21:41, 18 June 2007 (UTC)

No, nothing is wrong. If you read the article you'll realise that ascorbic acid is vitamin C. However, the reverse is not necessarily true, as vitamin C also takes other forms; therefore seperate articles. They have the same picture because ascorbic acid is the most common form of Vitamin C - 129.215.149.99 12:51, 22 June 2007 (UTC)

I'm fully aware of what both are. They are not the same thing. Vitamin C is the L-enatiomer of Ascorbic acid and should, therefor, have a different molecular picture. --THobern 16:06, 23 June 2007 (UTC)

POV Tags

I took a look at the points raise on the talk page of the Megadosing article and they don't seem to apply to this article. If they do, please specifically point out what is POV in this article. Pocopocopocopoco 03:41, 20 July 2007 (UTC)

Compensatory recyling of vitamin C in Humans?

Hi,

I have removed the following remark: though it has been suggested that the human requirement is far lower than that of other mammals, due to increased Vitamin C recycling efficiency.^[1] The reason: I have read it (quite dense stuff) and I did not find support to the idea that Humans keep vitamin C more efficiently than ascorbate-producing species. I let you jusge of what this review is about: Important progress has been made recently in our understanding of the synthesis and the recycling of vitamin C, and a novel pathway has been described for the degradation of vitamin C in bacteria. This forms the subject of this review. I looked, and I did not find anything specific on Humans or Simians being better vit. C recyclers. I know that this is very dense literature, but precisely, I wonder: who is going to go through the reading and check for accuracy? My opinion is that if, somewhere, there is something on us Humans being able to compensate for hypoascorbemia, it will probably appear in the abstract. Once again, I might be under an attack or pre-dementia, but I don't see that either. So I can't agree with this enhanced recycling idea. Pierre-Alain Gouanvic 05:09, 2 August 2007 (UTC)

In accordance with the previous fact check...

I have removed the 100,000 mg synthesis in an adult goat. I simply transferred the content of the quote, which states "many fold". This was done after checking, for about 45 minutes, if this 100,000 mg digit is validated (I don't have access to Chatterjee & al right now). Editors should remark that manyfold higher than 13 grams can approach this amount. If we suppose that manyfold means times 4, we have 52 grams. Times 7 would amount to almost 100 grams (91 grams, precisely). In any case, I think I respected the previous revision. My impression is that some editors had to feel reassured that this apparent lack of vitamin c intake could be compensated by uric acid. It should be noted that uric acid is also higher in primates, who still continue to eat from 2 to 6 grams of vit. C as we are editing wikipedia (or as we speak, if you prefer). So my insertion of the link to "vit C as a macronutrient - evolutionary rationales" is appropriate: putting reassuring hypotheses after troublesome facts is not appropriate.Pierre-Alain Gouanvic 05:50, 2 August 2007 (UTC)

Redoxon Image

I have restored this image. This brand for Vitamin C was historically the first. Its name was used for years to be synonymous with ascorbic acid. It is a fitting image for an encyclopaedia article to have. See Wikipedia:Deletion policy/Brand name products. Lumos3 21:09, 2 August 2007 (UTC)

I believe that guideline is with regards to articles about brands, not the treatment of brands within other articles. Not that I have any problem with the redoxon image. Ante lan ^talk 21:12, 2 August 2007 (UTC)

Cathcart Deletion

The section on bowel tolerance, along with the author are currently under wiki-review for deletion based upon WP:V and WP:SOAP. I'll wait until after the deletion review before removing the section. Djma12 ^(talk) 22:29, 9 August 2007 (UTC)

Esther C? Non-acid vitamin C?

What are these? Ewlyahoocom 05:43, 12 September 2007 (UTC)

recommended intakes somewhat nonsensual

Alternative recommendations on intakes

Some independent researchers have calculated the amount needed for an adult human to achieve similar blood serum levels as vitamin C synthesising mammals as follows:

400 milligrams per day: the Linus Pauling Institute.^[2]

500 milligrams per 12 hours: Professor Roc Ordman, from research into biological free radicals.^[3]
3,000 milligrams per day (or up to 300,000 mg during illness): the Vitamin C Foundation.^[4]
6,000–12,000 milligrams per day: Thomas E. Levy, Colorado Integrative Medical Centre.^[5]
6,000–18,000 milligrams per day: Linus Pauling's personal use.^[6]

when comparing these intakes to the vitamin C content of fruits given in the table below (varying betwenn 1 and 3100 mg/100g), some of these recommendations seem utter nonsense and not worth mentioning in wikipedia (the Vitamin C Foundation's RDA for Illness corresponds to 15 kg (!) of Rose hips, or 600 kg of oranges, which is quite illusory for daily consumption. even the "normal" RDA of 3000 mg/d would mean 3-8 kg per day of the most common fruits in the list. (and higher than the recommended maximum intake of 2000 mg/d stated in the paragraph above,nonetheless) That section needs work, and even if it's just a statement, that these figures are unfounded. That numbers should'nt stand there without discussion. (obviously, humans do not need the same vitamin C level as most mammals, thus the numbers are somewhat misleading)Chieron 13:59, 15 October 2007 (UTC)

Most of the high dose figures are based on the level of metabolism of vitamin C in the mammalian liver and one would not expect these to have been achieved through diet alone at any time in history. It is not "obvious" why humans do not require similar levels to other mammals and Linus Pauling and others have argued that they do. See Irwin Stone#Hypoascorbemia hypothesis. Lumos3 16:19, 15 October 2007 (UTC)

im not a scientist of any kind, but i searched for Vitamin C Foundation and what i found did not seem "independent". their website was advertising a particular brand of vitamin c (theirs, supposedly), plus advocating that artificial vitamins are just as good as natural ones. which is a lie. therefore i recommend to delete all mentions of Vitamin C Foundation, esp. as source, esp.esp. as independent source. or at least add some mark of "challenged neutrality"or something Anapazapa (talk) 00:46, 4 March 2010 (UTC)

Patent nonsense

The article opens:- "Vitamin C or L-ascorbate is an essential nutrient for all living organisms and plants. "

This is patent nonsense since most organisms and plants manufacture it themselves. Lumos3 (talk) 10:33, 4 January 2008 (UTC)

That is true that most produce Vitamin C but they still need it as an essential component for exsistence. An comparable example is humans produce insulin and it is essential for our survival. (Assuming that the person is not diabetic) I tend to agree in some way with your point on the use of the word nutrient. A nutrient is something which is taken from the environment. And in that respect to animals and plants which produce Vitamin C it is not a nutrient.

I'm unsure which point you were adressing so I tried to answer both I saw. Medos ^{(talk • contribs)} 13:28, 29 February 2008 (UTC)

The problem is that somebody decades ago hijacked the word "essential" and gave it a special context with respect to certain nutrients. This undermines the use of the word's general context in describing aspects of nutrients. All nutrients are "essential" (in the general context) for some purpose(s), but if you simply state that a nutrient is "essential" without qualifying the statement, you've made a word usage error. Worse is that those unfamiliar with the special context of "essential" and it's antonym "non-essential" will interpret them generally, which can have serious consequences. "Choline is non-essential" taken generally means that it's not essential for anything. But that's false. It's a precursor to the neurotransmitter acetylcholine and is essential for optimal mental function.

But the problem doesn't end there. Even though choline is non-essential in the sense that the body can produce some of it, the term "non-essential" still conveys the feel of the general context that it (or supplementation of it) isn't needed for anything. That is, the interpreter is still aware of the general context, and so its negative connotation is present even if the term isn't misinterpreted. It's suggestive. For example, let's say I create a new context for the word "fucker" which means someone who takes nutrient supplements. We're talking about nutrients, and you mention you take them, which makes you a "fucker". It's impossible not to feel or sense the more general context of the word, and this application of the word "fucker" vilifies (makes villains of) or belittles nutrient takers (via negative association to the general context of "fucker") in the same way that "non-essential" de-emphasizes important nutrients. The Transhumanist 07:04, 28 March 2008 (UTC)

This is a biology-related article so biological terms and definitions apply. --78.86.137.221 (talk) 09:38, 27 May 2008 (UTC)

Bad joke

From "Adverse Effects"

"Cameron also reported [Cancer and Vitamin C] that 1% of his patients in Scotland died from shock when their metastatic cancers underwent complete necrosis after receiving only 10 grams of ascorbate per day."

This sounds like a bad joke to me, as a non-medical person. Would be good to clarify this for the sake of the article's general quality which otherwise is quite high IMHO. —Preceding unsigned comment added by 91.105.197.75 (talk) 21:15, 4 February 2008 (UTC)

Citations to Vitamin C as a macronutrient section

The site http://www.seanet.com/~alexs/ascorbate/ (Ascorbate web) is part of the advocacy movement descibed in this section and contains an indexed list of scientific papers supporting large doses of vitamin c in a wide range of medical conditions. I believe the site passes Wikipedia's criteria as stated in WP:SELFPUB and should be retained in this section to which it is highly relevant. Lumos3 (talk) 20:00, 28 February 2008 (UTC)

I believe the individual citations listed within http://www.seanet.com/~alexs/ascorbate/ fall within WP:V and should be included, though articles published under Med Hypoth are not peer-reviewed and should not be presented as though they were.

The webiste itself is questionably self-published, but the more important issue is that it is an indiscriminate list of citations. Many of the listed citations are legitimate, some are below acceptable scientific standards, and a few fall way short of WP:V. As it is impossible to sort them out when the entire website is cited, it is much better practice to cite the specific article that is referred to. It takes longer to place in the specific citation, but I believe it is a better practice in the end.

Djma12 ^(talk) 21:37, 28 February 2008 (UTC)

The standard of the website is very poor.

It is just a general link to start. There is no indication as to which paper the information has been obtained.
The website is heavily pushing a POV in favour of taking large doses of evidence obscure and down right confusing quotes:
“A high intake of vitamin B6 was inversely associated with risk of stone formation... In contrast, vitamin C intake was not associated with risk...

“Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted.”

- Firstly: This was linked from articles that cliam to "Debunk Anti-Ascorbate Misinformation". All that can be assertained from these quotes is that there is no positive link between kidney stones and ascorbate. The main problem with this trial is that it was done using a questionaire. There was no dietary intervention so the accuracy must be questioned.
- Secondly: Taking information from a single source and claiming that it conclusively proves something is ridiculous. In order to prove something numerous studies must be done.
- Thirdly: Even if the statements taken from the article are true it Offers no justification to take large doses of vitamin C. It merely states that there is no risk associated with kidney stones, not that there is a clear medicial benefit.
This is one of many articles that I have looked at in this website. I have looked at a large portion of the "information" and it is all quoted in favour of vitamin C.

Use more reputable sources like pubmed, sciencedirect etc.

You have changed the sense of some of the sentences as you are attempting to put forward a POV.

You edited

despite a prolonged lack of conclusive medical evidence or large scale, formal trials in the 10 to 200+ grams per day range.

to

Critics, howver, maintain there is a lack of conclusive medical evidence or large scale, formal trials in the 10 to 200+ grams per day range

The sentence also changes its tone as a result. "Critics... maintain there is a lack of... ,formal trials" changes the meaning. In the previous version it was "...despite a lack of..., formal trials"

There is a lack of trials to justify the use of large doses. You have just made it opinion there.

I understand that you may have worked hard on it but it is not beneficial to put POV forward.

When your revert was undone by Djma12 you deleted "despite a prolonged lack of conclusive medical evidence or large scale, formal trials in the 10 to 200+ grams per day range." With this gone the tone is completely changed. Prior to that it spoke about both sides of the argument but you have put it completely in favour of taking large doses.

You then change a sentence to

There is a strong advocacy movement for large doses of vitamin C, promoting a great deal of added benefits largely based on based on published scientific reseach .

which completely changes the meaning of the previous section.

Djma12 has brought some clarity back, but please stop trying to front POV. It brings nothing to this article. Medos ^{(talk • contribs)} 11:07, 29 February 2008 (UTC)

Macronutrient section again

There is very serious POV pushing in this section of the article. It seems that there is clearly a passion for the topic but all the information is coming from very dubious source. The articles from the site are completely in favour of taking Vitamin C in large quantities. The main problem I have with the changes is the single source the information is coming from and the blatant lack of neutrality in the information. The site compiles articles which claim that Vitamin C can treat almost every condition imaginable such as addiction (to heroin), allergies, anemia, asthma, breastfeeding, diabetes, cancer, diphtheria, herpes, hepatitis, leukemia, measles, mumps, pneumonia, polio, septicemia, tuberculosis and others.

The site even warns that "unbiased opinion and opposing viewpoints is not guaranteed." The newest journal in the site is from 1999 and generaly if there's a journal that old there are 2 possibilites: 1. The science is not sound so there were no further studies done on it. or 2. There are newer and better designed versions of the trial to make it more credable.

An example of one of the journals was being referenced which I reverted.

Title:Correction of anaemia and iron deficiency in Vegetarians by administration of ascorbic acid

The journal claims that consumption of 1g of Vitamin C per day consumed as 500g twice per day will improve "hematologic and iron status" better "than iron salt administration". There are various flaws in the trial. The researchers not only examined people they knew personally, but medical and nursing students from the biochemistry department. Complince was measured on the basis that they were healthy individuals. This is absolutely ridiculous as there are healthy individuals who may never have to had taken medication in their lives. The trial also asks the participants to stop taking any iron suppliments that they are taking which is clearly altering the results. The trial volunteers' diets were not listed, which is the trials greatest weakness. Since the trial is taking highly educated individuals they would be more than capable of taking dietary measures to increase iron. There was no parallel trial to compare the data with.

For dietary trials to have any credability they should be at the very least randomised and hopefully blinded, preferably double blinded. This had none of these. Dietary trials also should require an acute knowledge of ALL food the participants are taking.

Other trials in the site are of similar quality.

This site claims is claiming that vitamin C is the cure for almost everything which is slightly irresponsible as some naive student could base all their work on such, or someone could start to base health advice on this site. To find the site please view the discussion above this one.Medos ^{(talk • contribs)} 23:08, 5 March 2008 (UTC)

I've finally had a chance to review the citations and agree. Many of the studies cited were flawed and fall under self-publication. Djma12 ^(talk) 01:07, 6 March 2008 (UTC)

Half-life: 30 minutes, or days?

An anon is pointing out that the half-life stated in the Vitamin C high dose arguments is 30 minutes. I'm encountering conflicting evidence for this.

"Once absorbed, ascorbic acid has a short in vivo half-life of approximately 30 minutes."
[1]: A key study in support of high dosages, I think. Also makes the 30-minute half-life claim.
"For man the half-life varied from thirteen to thirty days depending on the daily dietary intake of ascorbic acid."
Depletion and Repletion of Vitamin C in Humans by James Blanchard in 1990 points to a half-life of at least 6 days.

Can someone step in and evaluate? I'm not a medical person. Thanks. Carson 05:53, 25 April 2008 (UTC)

Like the second reference you give says, the half-life depends on the dose: "Low gram-level intakes of ascorbate, leading to blood plasma levels below 70 μM/l, have a half-life of 8–40 days. Higher gram-level intakes have a plasma half-life of 30 minutes". Biological half-lives are not generally constant, unlike radioactive decay half-lives. It makes sense intuitively that if you take vitamin C just at the required level, your body will try to retain it and use it as long as possible (weeks), but if you take a hundred times more than you need, your body will excrete it or metabolize it much more quickly (hours). Of course, it's not as simple as that because some compounds are easier to excrete or metabolize than others. But ascorbic acid, due to its high solubility in water, is easy to excrete. --Itub (talk) 08:47, 28 April 2008 (UTC)

Alright, in that case, what should be specified in the infobox? I'm leaning towards the longer half-life because a lower intake is typical. /Carson 04:57, 29 April 2008 (UTC)

Error in Plant Sources

Mango is listed twice in the natural plant sources section with differing concentrations. Which one is the correct one? 61.68.64.138 (talk) 10:47, 26 May 2008 (UTC)

WikiProject Food and drink Tagging

This article talk page was automatically added with {{WikiProject Food and drink}} banner as it falls under Category:Food or one of its subcategories. If you find this addition an error, Kindly undo the changes and update the inappropriate categories if needed. The bot was instructed to tagg these articles upon consenus from WikiProject Food and drink. You can find the related request for tagging here . Maximum and careful attention was done to avoid any wrongly tagging any categories , but mistakes may happen... If you have concerns , please inform on the project talk page -- TinucherianBot (talk) 01:16, 4 July 2008 (UTC)

really good

i thought this page was brilliant. i think it should be like a featured article or something. Splinked (talk) 22:10, 11 January 2009 (UTC)

Opening Vagueness

The article's intro contains the following sentence that seems out of place and far to vague for the introduction. I'm not sure what to do with it, but I don't think it belongs where it is. "However, a recent meta-analysis of 68 reliable antioxidant supplementation experiments involving a total of 232,606 individuals concluded that consuming additional ascorbate from supplements may not be as beneficial as thought." —Preceding unsigned comment added by Bigmantonyd (talk • contribs) 17:28, 27 January 2009 (UTC)

The first author listed in citation #30 (cocksryummy) looks like vandalism. Just happened to be browsing this article and it caught my eye. —Preceding unsigned comment added by 208.71.232.122 (talk) 19:11, 4 February 2009 (UTC)

Easy fix -- went to website, found article, corrected URL, corrected authors' names --SV Resolution(Talk) 14:56, 24 March 2009 (UTC)

Vitamin C levels for Wolfberries (Goji berries)

The Vitamin C figures for Wolfberry have been edited down over time, but I can't see a definitive source for this. Can anyone help? Greenman (talk) 09:59, 20 February 2009 (UTC)

Material deleted

Some material on high-dose arguments, interaction with cholesterol and blood vessels, and genes to synthesize vitamin C was deleted here. I'm noting this in case some editors might want to re-instate some of the material, perhaps with additional references to back it up, either in this article or in some other article where it might be more relevant. ☺Coppertwig (talk) 17:50, 16 March 2009 (UTC)

That section was heavily overweighted, but I would certainly not object to well-sourced expansion if I pared too far in this summary (note, I committed that particular edit). The bit describing the chemical synthesis pathway that the human line lost however many millions of years ago should probably go back in, but it needs a better source and should be in a different section. The cholesterol source discusses only in vitro work - suggestive, but overstated in the prior version; it is mentioned at Vitamin C megadosage. - Eldereft (cont.) 18:38, 16 March 2009 (UTC)

Why can't we produce it ourselves anymore?

Does anyone know why we lost the ability to synthesize our own vitamin C? Is this caused by lack of selection pressure due to high vitamin C levels in the diet? 82.139.87.249 (talk) 12:11, 6 April 2009 (UTC)

The hypothesis might have something to do with there being an actual DISADVANTAGE to retaining the metabolic tools when vitamin C was already available in the diet. Of course, we may never be able to figure it out for sure. --SV Resolution(Talk) 20:46, 20 April 2009 (UTC)

Incorrect and irrelevant citation, Fact check needed

A misleading or incorrect citation exists for the following claim from the "Possible side-effects" section:

A genetic condition that results in inadequate levels of the enzyme glucose-6-phosphate dehydrogenase (G6PD) can cause sufferers to develop hemolytic anemia after ingesting specific oxidizing substances, such as very large dosages of vitamin C.[114]

The citation has nothing to do with that claim. The article does not mention hemolytic anemia nor G6PD deficiency. The current, incorrect citation is:

Cook JD, Reddy MB (2001). "Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet" (PDF). Am. J. Clin. Nutr. 73 (1): 93–8. PMID 11124756. http://www.ajcn.org/cgi/reprint/73/1/93.pdf.

MaryNeedsSleep (talk) 23:03, 18 April 2009 (UTC)

Collagen, Carnitine, and Tyrosine synthesis, and Microsomal Metabolism sub section

What is being counted here? Can someone make it clearer . Is it molecules required or items in the list above.

Three participate in collagen hydroxylation.[40][41][42] These reactions add hydroxyl groups to the amino acids proline or lysine in the collagen molecule via prolyl hydroxylase and lysyl hydroxylase, both requiring vitamin C as a cofactor. Hydroxylation allows the collagen molecule to assume its triple helix structure and making vitamin C essential to the development and maintenance of scar tissue, blood vessels, and cartilage.[25]

2 are necessary for synthesis of carnitine.[43][44] Carnitine is essential for the transport of fatty acids into mitochondria for ATP generation.

The remaining three have the following functions in common but do not always do this: dopamine beta hydroxylase participates in the biosynthesis of norepinephrine from dopamine.[45][46] another enzyme adds amide groups to peptide hormones, greatly increasing their stability.[47][48]
one modulates tyrosine metabolism.[49][50]

Lumos3 (talk) 09:54, 7 May 2009 (UTC)

2 ref sections

Currently their are two ref section? Not sure why?--Doc James (talk · contribs · email) 00:02, 12 June 2009 (UTC)

food preparation

1st wiki edit, degradation in food seems to occur by a variety of means and can be significant, the previous comment about destruction only occuring at 190degrees c references the melting point of anhydrous ascorbate so not relevent to degradation in a biological soup, pun intended

Waiteantsee (talk) 15:06, 4 July 2009 (UTC)

vitamin C poisoning and confounding role of citrate in folk lore

I'll try to edit it but may not get around to it soon. But, there are at least isolated cases of people showing up in ER with crystalline kidneys after mega vitamin C consumption. Look at the metabolic route and you can get some idea of what happens here. For example, http://www.chestjournal.org/content/118/2/561.long it may not be quite the same as drinking anti-freeze but you get the idea.

Also anti-oxidants generally were hyped based on the notion of oxidative damage and the too-obviouso-to-question belief that "damage must be bad." In fact, much as with exercise causing "damage" various types of oxidative effects can be good and in fact reverisble ROS signalling has recently been discovered ( I think that yale grad student was working on PTP's for example). In fact, some of the vitamin K's are pro-oxidant and beta-carotene appeared to show a trend toward cancer increase in some clinical trials.

Personally, I think much of the effect attributed to vitamin C from folk lore could relate to the much larger amounts of citrate in common fruits. This helps clean up stuff and change host energetics to be less favorable for cancer. In any case, anti-oxidants seem to be more hype than reality.

ROS signalling, current events but may be more in historical lit to include, http://www.nature.com/nature/journal/v461/n7263/full/461486a.html "Reactive oxygen species are often blamed for the development of cancer and other diseases. Contrary to their 'bad boy' reputation, these species seem to be essential for the development of immune cells, at least in the fly." Nerdseeksblonde (talk) 00:25, 24 September 2009 (UTC)

Table of vitamin C content in foods

Bores me. This is not a good enough reason to spin it off into a sub list-article without input from other editors, but this article is already getting long. What say you all to moving this material off to its own list (table article?) first, leaving behind a few sentences expressing the essense of the best and worst of the foods, and most common, in vitamin C content? S B H arris 02:50, 24 September 2009 (UTC)

I'd be really happy about it, as it's the only bit I'm really interested in editing, and as you can see from my recent edits, I believe it needs it's own set of citations because the information is all just plain wrong or misleading and needs to be fully cited to 1 or more sources. Donama (talk) 03:40, 10 February 2011 (UTC)

Should Vitamin C really be categorized as antidepressant?

I think not. Discuss! —Preceding unsigned comment added by Harbinary (talk • contribs) 15:16, 9 October 2009 (UTC)

The only mention of anti-depressant properties I can see is if you have Scurvy.Ljcrabs (talk) 01:09, 30 December 2009 (UTC)

Lacking crucial information. What is Vitamin C ?

"In 1928 the Arctic anthropologist Vilhjalmur Stefansson attempted to prove his theory of how the Eskimos are able to avoid scurvy with almost no plant food in their diet, despite the disease striking European Arctic explorers living on similar high-meat diets. Stefansson theorised that the natives get their vitamin C from fresh meat that is minimally cooked."

If this was in 1928, then this was before Vitamin C was ever isolated as acorbic acid. If this was the case, then what were people referring to when they used the term "Vitamin C"

In Albert Szent-Gyorgyi's Nobel prize lecture, he comments "From the beginning I had suspected that the substance was identical with vitamin C", referring to ascorbic asic or "hexuronic acid", as he first named it.

So what then is this Vitamin C that he is referring to? This is a wonderfully thorough article on vitamin C. But it neglects one crucial bit of information: the definition of Vitamin C that was used to confirm that isolated ascorbic acid is in fact the same thing as vitamin C once it was isolated.

I should think this would be the highlight of the article, yet it doesn't even exist. There needs to be a definition for Vitamin C, defined accurately enough that if I were the first one to isolate an unknown substance that happened to be Vitamin C, I would be able to use the definition in order to identify my isolated substance as vitamin C.[Special:Contributions/66.183.139.155|66.183.139.155]] (talk) 02:56, 21 November 2009 (UTC)

The chemical formula and structure are in the box at the right of the opening paragraphs - does that not have the information you seek? - 2/0 (cont.) 04:42, 21 November 2009 (UTC)

Actually it doesn't. Vitamins are defined by biological activity, not chemical formulae. Vitamin C was defined in the guinea pig antiscorbutic model biologically before it was structurally identified. This sequence is necessary for all vitamins: biology first, chemistry second. S B H arris 04:53, 21 November 2009 (UTC)

Thank you Sbharris. Yes. This article is very thorough, but fundamentally flawed. This article starts by listing alternative names for Vitamain C as compounds (L-ascorbic acid or L-ascorbate), which I find inappropriate, since we are talking about a vitamin and not a compound here. From the wikipedia article on Vitamins: "Vitamins are classified by their biological and chemical activity, not their structure. Thus, each "vitamin" refers to a number of vitamer compounds that all show the biological activity associated with a particular vitamin." Just because Vitamin C only refers to one vitamer compound, "L-ascorbate", does not make them one and the same. Furthermore, the biological activity that gives this vitamin its name is not clarified anywhere in the article (obviously a concise definition exists, or its vitamer compound "L-ascorbate" could not have been ever isolated). The comment from the above poster: "The chemical formula and structure are in the box at the right of the opening paragraphs", exemplifies the confusion that this article instills in the reader. The alternative compound names for Vitamin C need to be removed. And this article on Vitamin C will definitely not be complete until the question of "Why L-ascorbate is a vitamer compound of Vitamin C?" has been clearly established. I am not nit-picking here. This really needs to be corrected, because it leads to a deeply flawed perspective of what Vitamin C is and where the term comes from. Timeofmind (talk) 21:52, 28 September 2010 (UTC)

LOL. From the top of the article: "This article is about the nutrient. For the chemical compound, see ascorbic acid. For other uses, see Vitamin C (disambiguation)." Then the article goes on to use the name for the chemical compound "ascorbate and ascorbic acid" interchangably with the word "Vitamin C". This blatant ambiguation of the word "Vitamin C" diverts the writer off topic into reproducing information about ascorbic acid which has no place here, and should instead be left to the "ascorbic acid" page. The whole first paragraph of this article is completely off topic. Timeofmind (talk) 22:03, 28 September 2010 (UTC)

I want to further stress how confusing the first paragraph of this article is to someone who is unfamiliar with the relationship between "Vitamin C" and its vitamer compound "ascorbate". The writer immediately goes into a frenzy talking about properties of the compound before ever even making mention of the vitamin other than that it is essential for humans. Lets establish why ascorbate is a vitamer compound of Vitamin C before talking about ascorbate or ascorbic acid. Timeofmind (talk) 22:23, 28 September 2010 (UTC)

For starters... when was the term "Vitamin C" first used? By whom? This person was using the word to refer to what? I know it was long before ascorbic acid was ever isolated. Timeofmind (talk) 22:30, 28 September 2010 (UTC)

New citation tool

You can use my tool to get pubmed eutils hits in wiki format for help.

I have temporarily set up a web test for my tool to convert the pubmed search results into a list of wiki citations. If you change the "url=" value to your desired search,

http://www.spottext.com/wikimed.cfm?url=%22hexuronic+acid+pathway%22

It turns out there are only two hits on this but you can play with the url parameter or find your own criteria using the pubmed webinterface. Note that many edu site have lecture notes online too sometimes with historical perspective. Nerdseeksblonde (talk) 11:57, 21 November 2009 (UTC)

Talk:Vitamin C/Archive 2/GA1

There is evidence vitamin c is good for gout

http://www.abc.net.au/science/articles/2009/03/10/2512339.htm —Preceding unsigned comment added by 122.106.36.154 (talk) 10:27, 27 February 2010 (UTC)

Would somebody kindly indef block user:Nylashia5 as a vandalism-only account?

Based on edits to this page? There's really no excuse for this, and there's really no point in warning anybody who edits like that. Thanks. S B H arris 17:43, 27 May 2010 (UTC)

Merge with Ascorbic acid

Why do we have two articles about the same chemical? —Preceding unsigned comment added by 71.93.61.178 (talk) 02:14, 8 June 2010 (UTC)

"Vitamin C" refers to the dietary component which counters scurvy. Ascorbic acid is the principal antiscorbutic component in foods, but dehydroascorbic acid can also be absorbed from food and converted in the body to ascorbic acid. Dehydroascorbic acid is therefore also a form of Vitamin C. "Vitamin C" and "ascorbic acid" are not synonyms. See, for example, ^[7]

Rectifico (talk) 19:55, 17 June 2010 (UTC)

I removed the Merge with Ascorbic acid flag, as the consensus there is that they should stay separate articles. 5Q5 (talk) 17:49, 7 July 2010 (UTC)

New article for list of plant sources

I am proposing a new article for the section 'Natural and synthetic dietary sources/Plant sources' - The table can be made to fit in single column and additional information/references can be added. Something like List of plant sources by Vitamin C content Sibi_antony (talk) 03:00, 4 October 2010 (UTC)

I like it. The vitamin articles tend to get crowded with LISTS of foods high in the vitamin, and these are just naturally LIST type things: see WP:LIST. Tables and lists should go in dedicated list articles. They are underused in WP. The subsection can refer to the dedicated list article as a {main} and it then doesn't end up using space here. The top 5 foods, or perhaps a summary of TYPES of foods, or both, can go in the vitamin article. S B H arris 02:36, 13 November 2010 (UTC)

Agree with both of you. But see talk section above on popping this section out the a new article. It should be about all natural sources, including animal sources -- not just the plant sources. Cheers, Donama (talk) 03:43, 10 February 2011 (UTC)

Vitamin C megadosage - conclusion

"Though vitamin C has been promoted as useful in the treatment of a variety of conditions, these uses are poorly supported by the evidence and sometimes contraindicated.^[8]^[9]^[10]^[11]"

I assume the removal of this content is going to get challenged. From reading each of those sources, I can not find any that actually makes the claim thats the author do. Based on that, I can only assume its a drawn conclusion where the 4 sources are there to back the conclusion up. While the conclusion could be correct, Wikipedia don't do conclusions (see WP:NOR#Using sources). It would thus be better if it was rewritten where the different research was summarized so the reader can make his own conclusions if he thinks that the evidence is poorly or if there is contraindictions.Belorn (talk) 07:31, 17 January 2011 (UTC)

I've replaced this information. Though we are not supposed to synthesize conclusions, these sources do, in my mind, support this information. WLU (t) (c) Wikipedia's rules:^simple/_complex 12:29, 14 February 2011 (UTC)

Removed from lead

Hopefully, it can be incorporated somewhere else:

However, it is effective at preventing cold when consumed regularly by athletes exposed to periods of training in subarctic conditions (i.e.marathon runners, skiers and soldiers on subarctic exercises).^[12] In one study vitamin C supplementation significantly reduced the frequency of the common cold but without apparent effect on the duration or severity (however the authors of this research pointed out that the findings should be interpreted with caution).^[13] Recently, result of a meta-analysis of 29 trials involving 11,306 participants showed that regular vitamin C supplementation (oral doses of 0.2 g per day or more) reduced duration of cold both in adult and children by 8%-13%, respectively. The severity of cold has also been significantly reduced in people on the regular vitamin C supplementation.^[14]

--Jorfer (talk) 02:26, 11 February 2011 (UTC)

I put some of it in the treatment section later, and only modified the old lede sentence a bit (so that it reflects the best of our knowledge, which is a small effect on cold duration). If you suffer 28 days of cold a year it might save 2 days of mild dyscomfort, and at a cost which is almost nil. And since it's one of the few things most people "know" about vitamin C, we might as well get the facts (as close as they are known) up front. S B H arris 01:04, 14 February 2011 (UTC)

Vitamin C megadosage and chemo; Heaney et al criticized

This edit from WLU has an issue: it uses a research article which has been directly criticized. Levine et al point out:

In direct contrast to Verrax/Calderon, Heaney and coworkers just months ago reached exactly the opposite conclusion: that vitamin C antagonizes chemotherapeutic agents [29]. What explains this difference? Whereas Verrax and Calderon used ascorbate, Heaney et al. used dehydroascorbic acid (oxidized ascorbate), but called it vitamin C. This incorrect nomenclature leads down a slippery slope. All known actions of vitamin C are mediated by the reduced molecule ascorbate, not dehydroascorbic acid. If dehydroascorbic acid was equivalent to ascorbate, mice lacking the tissue ascorbate transporter slc23a2 should have normal tissue ascorbate concentrations. Instead, tissues are severely ascorbate deficient, and the mice die at birth [30]. Verrax and Calderon administered parenteral ascorbate to animals and measured pharmacologic ascorbate concentrations, findings that have clear translational application. By contrast, Heaney et al. administered dehydroascorbic acid at pharmacologic concentrations, which does not translate to people because dehydroascorbic acid is diabetogenic [31]. Verrax and Calderon also showed in their animal model that high doses of oral ascorbate did not increase tumor growth, a concern alluded to by Heaney et al. and now directly addressed.

Therefore, I will be removing it shortly. It will probably be a while before we hear the results on the bigger clinical trials of vitamin C and cancer. II | (t - c) 20:14, 11 February 2011 (UTC)

Levine et al at pubmed or as pdf. That's a letter to the editor, not a full article, and isn't really suitable as a source (they cite Cameron et al 1975 as supporting the belief that vitamin C can treat cancer despite Cameron's results being spuriously based on noncomparable groups). Despite vitamin C being pushed as a CAM chemotherapeutic agent for decades, and despite several investigations, there is no evidence I am aware of supporting any form of vitamin C in the treatment or prevention of cancer. This is one of the rare instances where I would support the inclusion of a primary source - it's a brief summary of an article with a finding that directly contradicts a fringe belief that has been promoted for years without any solid proof to substantiate it. I've added "in vitro" to the text; thirty years of claims by CAM pushers with no positive results but no decrease in promotion suggests it is worth noting that in vitro tests contradict these claims. Meanwhile Heaney et al (full text) chose to use dehydroascorbic acid because it is "the commonly transported form of vitamin C" which "is reduced to ascorbic acid and trapped intracellularly" after transport. Special pleading and goalpost moving regarding vitamin C and cancer still has produced little more than excuses and has still failed to produce any meaningful data supporting the use of ascorbic acid in the treatment of cancer, as noted by Cabanillas, 2010. I believe the short notice of the potentially damaging effects of vitamin C on chemotherapy effectiveness should remain. WLU (t) (c) Wikipedia's rules:^simple/_complex 03:07, 13 February 2011 (UTC)

As I've mentioned to you before, I would prefer if you stuck to the topic at hand rather than getting into personal soapboxing. This would be to your benefit, since once you make your personal biases so clearly evident, your neutrality and objectivity appear questionable. As you might imagine, you and I have dramatically different views on medical science, and particularly the influence of authorities and preconceived biases on opinions and research practices - so if either of us get into our personal opinions it will probably just annoy the other person If we're trading opinions, I lack scientific respect for anyone who would purport to replicate research when the person does not actually replicate the research - as the medical establishment did when they tested vitamin C for cancer orally but not intravenously (I don't care if it was just 10 days or whatever), and then wouldn't even publish Pauling's comments. After reading your response, I think you either looked at Levine too quickly or we might have different views on integrity in basic communication. Please meditate on the following:

(1) You said that Levine et al's article is a "letter to the editor"; in fact, the article does not have the word "letter" anywhere, but is labeled a "commentary". I know you read medical journals, so you are probably aware that experts are often invited to do editorials or commentaries for major research findings.
(2) You are an outspoken advocate of WP:MEDRS, which advises to respect secondary sources - individuals who are one step removed from the authors of primary research articles - in order to respect the experts. In this case, we have Mark Levine and his two colleagues. Mark Levine has been researching vitamin C at the NIH for a couple decades and has an MD from Harvard. Yet you would advise that we ignore his comments because they do not fit your preconceived opinions.
(3) Levine's commentary is on Verrax and Calderon's finding that ascorbate increased the cytotoxicity of chemotherapeutic agents both in vitro and in vivo. In contrast to Verrax and Calderon, Heaney et al is only an in vitro finding, using a different substance which presumably will not be used in clinical trials, since Mark Levine, as a major NIH figure in the subject, will presumably have influence on subsequent ones (such as the 5 clinical trials pending). As I recall, you once said that "you can throw anything at a cell in a petri dish and the cell will die" - now, I'll admit you retracted that obviously ridiculous statement, but still, you generally don't believe in discussing in vitro research. However, it seems you make an pretty big exception where the in vitro research supports your personal beliefs. II | (t - c) 10:19, 13 February 2011 (UTC)

Ah, I've confused a couple things. This is Heaney et al., which has a comment here and author reply here. I had thought Levine et al was the letter to the editor but it's actually a commentary on this article.

That being said, MEDRS does allow the citation of primary sources: "Reliable primary sources may occasionally be used with care as an adjunct to the secondary literature, but there remains potential for misuse. For that reason, edits that rely on primary sources should only describe the conclusions of the source, and should describe these findings clearly so the edit can be checked by editors with no specialist knowledge. In particular, this description should follow closely to the interpretation of the data given by the authors, or by other reliable secondary sources. Primary sources should not be cited in support of a conclusion that is not clearly made by the authors or by reliable secondary sources, as defined above". You are correct that I generally do not support the citation of primary sources in medical articles, but I am willing to make exceptions and this is one of them. I think the source provides important context on the vitamin C-chemotherapy debate - the fact it has been found to oppose chemotherapeutic agents in vitro. Given the fact that vitamin C as a chemotherapeutic agent is still a fringe hypothesis with no mainstream support, it's noteworthy when results exist that contradict it.

Levine isn't a literature review or meta-analysis, the types of secondary sources MEDRS supports, it's a commentary.

Thank you for your personal commentary, though it's a little hard to take seriously given the exact same criticisms can be applied to your own perspective as a proponent of orthomolecular medicine. Would you like to settle this via third opinion or request for comment? WLU (t) (c) Wikipedia's rules:^simple/_complex 14:21, 13 February 2011 (UTC)

I'm not a proponent of orthomolecular medicine per se - I can't really blame you for being snide since my last response was obviously pissed off, but automatically putting people into boxes which they haven't put themselves into is another thing you should try to avoid, since habits like that have several negative effects and also puts automatically you into a box that you probably don't want to be in.

As far as the issue at hand, please see Frömberg et al, which discusses both Heaney et al and Verrax & Calderon's research in-depth from a secondary perspective and basically replicates both their findings. If you really think this needs to be discussed, the most fair thing to do, of course, is to note both phenomena. As far as Levine et al not being a review, it is identical in all meaningful respects to a narrative short literature review - what, besides the byline, is the difference?

As far as the personal commentary about proper replication, it is puzzling for you to say such a thing since, in general, orthomolecular proponents don't really do clinical trials, and thus I cannot think of a case where the proponents purported to refute some finding through unrealistic or non-similar research. But if you can point to some examples, I'd love to hear them. I'm not going to say that the proponents are right all the time or even most of the time (they are probably wrong most of the time, as I've said quite a few times), but then again they aren't respected scientists entrusted with billions of dollars of public money. With the power and prestige of being a part of the medical establishment, there's a higher expectation of scientific integrity. II | (t - c) 18:57, 13 February 2011 (UTC)

Since you both seem to be seeking a third opinion, I would cite both the vitro results that are in the article now, adding that in vivo animal model tests have not been replicated, and add Frömberg, to act as cites on a simple note that in vitro tests of vitamin C on cancer have been inconclusive, with the suggestion that vitamin C's effect on cancer may depend on the oxidation state of vitamin C. But in vitro tests on cancer are always the poorest kind of evidence. In vitro testing of various chemotherapeutic agents against cells of particular patient's tumor (which in practice is often possible) still has yet to be well-established as being informative!

As to the Cochrane reviews, it seemst to me that the cites don't support what the text says. The first review on lung cancer is thoroughly contaminated with beta-carotene results, and I don't think addresses vitamin C at all; I would remove it from THIS article. The second one on GI cancers has vitamin C data, but seems to find positive effects of selenium and negative effects of carotinoids, but is pretty neutral on the vitamin C. Thus, as a neutral result I'm not even sure it's worth citing except to say that the best meta-analyses of prevention of GI cancer with vitamin C are neutral and (although not perfect studies) don't indicate an advantage of the doses used in the conditions and populations looked at. The most interesting point is the 5 active clinical trials ongoing of vitamin C as ascorbate as an adjunct therapy in treatment of cancer, and that should be added to this article, with the clinicaltrials.gov cite given (even the suspended trial is suspended on legalistic issues, not result issues). So we don't know yet, but probably will soon know more. We should probably just emphasize that lack of knowledge in cancer for now, and leave it that way, for now. What do you say? S B H arris 02:09, 14 February 2011 (UTC)

From a WP:FRINGE perspective, the "alternative" theory is that vitamin C is a potent curative agent in the case of cancer. Citing in vitro and primary sources in general to support this position is therefore inappropriate, particularly given the most recent review that states there is no evidence to date that vitamin C has any significant anticancer properties. I favour retaining Heaney because it not only supports the mainstream position, it also suggests vitamin C may actively interfere with proven treatment. In other words, I agree with your analysis and just wanted my own reasoning written down.

I also don't have an issue with your analysis of the Cochrane reviews. I thought I had been the one to include them initially and I'm normally pretty scrupulous regarding the wording - but in both cases worked exclusively from the abstract. The lung cancer review doesn't mention vitamin C in the abstract, but it does appear in the plain language summary. If the full text doesn't give extra and specific detail on vitamin C, then the information should be adjusted - neutral for GI and remove lung if the full text doesn't discuss it.

I'm normally not a fan of citing clinical trials that are upcoming or ongoing, unless the information is appearing in a peer review article. Trials get interrupted, cancelled, put in a file drawer or simply discarded if their results are not positive. At "best" I would prefer to note only that there are trials on going with no details. WLU (t) (c) Wikipedia's rules:^simple/_complex 12:10, 14 February 2011 (UTC)

Note the SENECA study finding an increase in mortality for smokers who took supplements, including vitamin C. Not a secondary source, but it does look specifically at lung cancer. WLU (t) (c) Wikipedia's rules:^simple/_complex 12:26, 14 February 2011 (UTC)

Regarding vitamin C and cancer, it seems a trifle generous to say that a review article in the Puerto Rico health sciences journal reflects the mainstream view, while other recent review articles in publications such as Anticancer Research (PMID 19414313), Immune Network PMC 2816948, and Biochemical Pharmacology (PMID 18938145) represent a "fringe" view. In any case, I don't really have a lot of time to spend on this topic - I'll just come by in a few years and fix it then. Incidentally, vitamin C: update on physiology and pharmacology (2009) is freely-available and provides some good information. And I'm sure WLU in particular would get a kick out of "Micronutrient synergy--a new tool in effective control of metastasis and other key mechanisms of cancer", a "review". II | (t - c) 19:22, 14 February 2011 (UTC)

Cabanillas, 2010 explicitly examined clinical trials of humans. Verrax, 2008 summarized pharmacokinetic data of pharmacological levels of vitamin C achievable only through IV and a rationale of a potential process through which it might possibly be a chemotherapeutic agent. Ohno, 2009 is also an examination of pharmacokinetic data with some case studies. Lee, 2009 is also about potential antitumour activity. The idea that vitamin C is a chemotherapeutic molecule, let alone a potent one in humans is not yet supported. There are clinical trials ongoing, but I don't think vitamin C should be portrayed as a well-regarded, promising intervention when well-controlled studies have consistently been negative. Though admittedly every single combination possible hasn't been tried (intravenous versus oral, chemo versus no chemo, high dose versus low dose, different types of tumours, different stages of cancer, different genetic background of patients) that doesn't mean that there is a variant out there that we know works and is just waiting to be discovered but does reflect the consistent goalpost-moving . It has been believed for years that vitamin C is a potent chemothereapeutic agent, but solid proof has always been lacking. I think the page should reflect that. The opinions of AIDS denialist and owner of a large vitamin sales company do not interest me in general and are irrelevant on this page in specific. There is reason to distrust pharmaceutical companies due to their profitting off of the results of medical studies. There is more reason to distrust vitamin pushers since the evidence threshold to sell them is far, far lower - vitamins need only safety, not efficacy data in order to be sold in the US. But irrespective, I do not appreciate barbs being lobbed my way, please stop. WLU (t) (c) Wikipedia's rules:^simple/_complex 20:57, 14 February 2011 (UTC)

What about this!? http://www.ncbi.nlm.nih.gov/pubmed/21525621 And many like it! Why is this not cited? Or the story of that guy in NZ with pneumonia? Fringe!? Seriously? Why do people have a problem with including MORE information from the news or legit journals. 173.53.102.90 (talk) 02:46, 20 May 2011 (UTC)

Kakadu Plum

Is there any sources for the vitamin C content of this? Neither this page, nor the Terminalia ferdinandiana page list sources. If there are no sources, surely it should be removed? Heywoodg (talk) 22:15, 23 March 2011 (UTC)

Brand Miller, J., James, K. W. and Maggiore, P. M. A. 1993. Tables of composition of Australian aboriginal foods, Canberra, A.C.T: Aboriginal Studies Press. VertebralTomb (talk) 19:32, 2 November 2011 (UTC)

"Volunteers"?

Whny the scare quotes on the Iowa State Penitentiary volunteers for scurvy studies? --Yaush (talk) 22:35, 19 July 2011 (UTC)

Because imprisoned people who may get out early, or some special favor which only restores what everybody else has, are not really volunteers in the true sense of the word. They are under heavy duress. That is why using prisoners as medical subjects has generally been outlawed-- they can't really give free consent. If you consider the idea of female prisoners volunteering to have sex with their guards, you'll see the point. S B H arris 02:27, 20 July 2011 (UTC)

This rationale for the scare quotes seems to me to violate WP:NPOV. If removing the scare quotes is also thought to take sides on a controversy unrelated to Vitamin C, I suggest we drop the word "volunteers" completely. I'm going to go ahead and make that change. --Yaush (talk) 14:03, 20 July 2011 (UTC)

Vitamin C effect on colds in cold-excercise

A preventive effect of vitamin C on colds has been seen in five separate prospective randomized double-blind placebo-controlled human trials of low temperature exercise. Here are three: [2]. Also the meta analysis of this data combined is strongly positive. This is not "cherry picking" data, as each of the separate trials were designed to answer this specific question, so there is no post-hoc data selection of data that was never meant to be used in this fashion. Nor are there negative trials which have been overlooked by Cochrane. (If you think so, find them). In such cases, a meta analysis strengthens a conclusion, not weakens it. Nor is Cochrane Review known for its credulous data manipulation! As I said in the summary, if you won't believe in gold standard data of this type, what sort of data WILL you believe? I've restored the statements, which are fully justified. S B H arris 00:34, 23 August 2011 (UTC)

Vitamin C Absorption

The section on vitamin C absorption is in accurate. The absorption study referenced did not measure doses above 1.25 g. VertebralTomb (talk) 19:35, 2 November 2011 (UTC)

I fixed the relevant text. The reference to the absorption of 12+ g was removed, as there was no reference listed for that data.VertebralTomb (talk) 16:09, 3 November 2011 (UTC)

oxidative quackery

My understanding of this is that 'oxidative stress' is a somewhat controversial topic, and not everyone is in agreement about it as a genuine issue for biological systems. Vitamin C has become associated with this nonsense since it is a reducing agent. And I do know what that term means.

Vitamin C seems to be viewed as a sort of 'cure all' these days when it's principal role is very clearly to act as a cofactor in collagen synthesis. This seems to be buried in the middle of all of this drivel when it is the most important thing by far that Vitamin C is involved in. A fact that is surely clear to anyone who knows what scurvy is.

This article and indeed this discussion page are far far far too long! Perhaps someone would like to sprinkle some vitamin C on it and reduce it (lol)! Johnpretty010 (talk) 00:54, 24 September 2011 (UTC)

This is a very poor summary of the functions of vitamin C. Ascorbic acid has a wide number of biological functions, and only some are known. While the term 'oxidative stress' might be debated because it is often improperly used, it is clear that it is an issue for biological systems and has serious health effects. The role of vitamin C is still being elucidated. VertebralTomb (talk) 19:31, 2 November 2011 (UTC)

Seems a fair enough summary to me. You say:

"Ascorbic acid has a wide number of biological functions, and only some are known."

lol, can anyone spot the obvious stupidity of this statement?

The primary function of Vitamin C is that it acts as a cofactor in collagen bisynthesis. That is a very good, simple and clear summary of the primary function of vitamin C. How do I know? Because vitamin C deficiency results in the disease scurvy. QED! — Preceding unsigned comment added by John2o2o2o (talk • contribs) 21:33, 6 July 2012 (UTC)

Just to add clarity here: Collagen makes up about one third of the whole of the body's mass of protein. That is a heck of a lot of protein and it therefore requires a heck of a lot of Vitamin C to make it. (Which is I suspect the real reason why vitamin C can be ingested in such relatively high doses). Therefore THE PRIMARY FUNCTION of vitamin C in the body is in collagen biosynthesis!

The name "ascorbic acid" even comes from the latin word for "scurvy" - the collagen disease that results from Vitamin C deficiency! Therefore it should be right at the top of this article. "Oxidative stress" - which I still contend is highly suspect - should be mentioned, but not given "top billing". To place it at the top is to imply that combating it is the main function of vitamin C and that is very very misleading and very very wrong! John2o2o2o (talk) 22:05, 6 July 2012 (UTC)

Agreed. Since collagen weakness syndromes (including leaky vessels) are at the top of problems that first show up in vitamin C deficiency, clearly collagen should be given top billing as far as what is known. Thanks for noticing. It it's not fixed already in the lede, I'll do it. S B H arris 22:40, 6 July 2012 (UTC)

Very good. That is the appropriate emphasis and prioritization. __meco (talk) 11:44, 7 July 2012 (UTC)

the goat's vitamin C

its probably worth noting that a goat can make as much as 100g (100,000 mg) of vit C when stressed, while 13g is their norm. stating how much extra makes it more interesting. Charlieb000 (talk) 03:37, 26 March 2012 (UTC)

Stone says this about the goat, but I'm very skeptical. Let's see the primary reference for it (the actual experiment where somebody measured it with radiotracer dilution or something). I know this is in the article now, but I've never really believed it. Stone quotes Chatterjee 1973-- this is probably Chatterjee, I. B., Science, 182, 1271–1272 (1973), which I'll need to look up. But I think it's a liver slice study, which certainly does not translate well to the whole animal, as you can't assume that the liver in a dish is doing the same thing in a whole goat. Then there's quoted an article by Subramanyan where he says mammals increase vitamin C production in stress many times, and perhaps Stone just ASSUMES goats do that, too, and thus estimates 100 grams a day (per 150 lbs) without anybody ever having measured that in goats and checked to to see if it's true, there. All this is pretty bad referencing and a lot of supposition and a long chain of assumptions. S B H arris 17:24, 26 March 2012 (UTC)

You can't assume anything from these calculations. Besides doing strange calculations based on body size, you also have to realize that the rate of vitamin C synthesis in animals is not a constant, and fluctuates based on need. Certainly liver slices in a dish are exposed to a greater amount of stress than an intact liver, thus up-regulating their synthesis capacity. If man was required to take up gram doses of vitamin C, we would be able to absorb them. We do not. I have removed a lot of this discussion as is not relevant to the topic of vitamin C synthesis. If anything it would go under a 'Estimated Requirements' subheading. --VertebralTomb (talk) 15:16, 8 June 2012 (UTC)

is it safe for pregnant woman to take in ascorbic acid — Preceding unsigned comment added by 121.202.22.118 (talk) 22:14, 19 June 2012 (UTC)

Should we renominate this for featured article?

I've been looking over this article, and its pretty comprehensive, well sourced and attractive. Should we try again for FA? It's been three years now since it failed! Must've changed loads. I think there could be some reference cleanup and there are a few loose {{fact}} tags, but apart from that I can't see any other major reasons why it would fail... If anyone sees any, could you outline them here and I'll help fix them and we can try again for FA. Woop! Jack · talk · 21:56, Monday, 19 February 2007

I've nominated this for a GA review, a crucial step the way - Jack · talk · 05:23, Wednesday, 21 February 2007

Certainly its sage information on plant sources of Vitamin C could help it it to achieve featured status. For a long time, I thought that the acerola was the bes source of Vitamin C, but it was only from a television programme over this year (I think September 2012) that I learnt there is a better source - the camu camu, and this article does rightly say it has more Vitamin C than the acerola. I did know that the acerola has more Vitamin C than the blackcurrant, and it is good to see that this article gets this correct. ACEOREVIVED (talk) 15:54, 9 October 2012 (UTC)

Protection request

{{adminhelp}}

Uncooperative IP at work on two articles. An IP who changes IPs is edit warring and not discussing. The IPs have been warned.

See: Category:Suspected Wikipedia sockpuppets of 80.133.57.193

Brangifer (talk) 23:39, 4 July 2012 (UTC)

Protected - it will be quicker to go to WP:RFPP Ronhjones ^(Talk) 01:16, 5 July 2012 (UTC)

Edit warring about "criticism"

Brangifer, you are the one who initiated the edit war. I, unlike you, am trying to incorporate scientific contributions. My last two edits, which were again reverted, referenced a peer-reviewed review, not letter. How can this not be considered compliant with WP:MEDRS? You stated that "letters" were not compliant with WP:MEDRS. However, WP:MEDRS only explicitly forbids letters from non-experts. The letters I originally referenced were from university researchers, i.e., experts in their respective fields published in scientific journals. In conclusion, your original claim - and reason for reverting my contributions - that all letters were incompliant with WP:MEDRS is not supported by WP:MEDRS. You further claim that I were using sock puppets when, in fact, I am simply using an Internet connection with dynamic IP address assignment. I do not see Wikipedia as a social network, I do not wish to maintain an identity here and care even less about self-congratulatory user pages plastered with pathetic symbols of virtual achievements. To use Wikipedia's silly jargon, I am generally a "WikiGnome" and hate to be dragged into all this drama just because of power-trippers like you. — Preceding unsigned comment added by 80.133.40.80 (talk) 01:29, 5 July 2012 (UTC)

First of all, the edit warring started when you restored what I had reverted. WP:BRD isn't spelled BRRD. When your edit is reverted, you are obligated to discuss the matter on the talk page, and hopefully reach consensus, before attempting to restore it. That's the ONLY surefire way to determine who started an edit war.

Secondly, please describe the content of that addition, preferably exact quotes, author, etc.. The link provides no such details. If it's primary research, we can't use it. If it's a letter, we still can't use it. It's pretty rare that we allow such things.

Thirdly, when you know that you have a dynamic connection, you must register an account. Our rules forbid appearing as more than one person/using more than one account. There are legitimate ways of using sock accounts for certain purposes, and this is NOT one of them. Every single edit you, as a single person, make, should be credited to one contribution history. The only way for a person using a dynamic connection to do that is to register an account. You don't have to do anything with your user page, but you must learn to edit collaboratively and respond to any comments on your talk page. You can't edit as an island here. You are part of a community here, and if you can't handle that, then don't make any controversial edits. Hit and run editing doesn't work. You must leave edit summaries and respond to them. You must also use the article's talk page. Communication is the key. It's all up to you. -- Brangifer (talk) 05:29, 5 July 2012 (UTC)

First of all, "BRD is not a policy. This means it is not a process that you can require other editors to follow." You again try to misinform (cf. "obligated") to your advantage.

Second, do I understand your second point right? You haven't even read the sources I reference, including the review, yet chose to revert my contributions anyway? Said review is referenced by PMID, authorship is apparent and does indeed contain methodological criticism of the aforementioned study. I do not have to spoonfeed it to you just because you are the self-appointed gatekeeper.

Third, an IP address is not a personal identifier; it is merely a technical necessity for communication between machines, not people. Therefore, your claim of intentional or unintentional sockpuppetry does not follow. — Preceding unsigned comment added by 80.133.50.170 (talk) 09:20, 5 July 2012 (UTC)

First, it's still a widely respected guideline. Refusing to respect it and edit warring is still an uncollaborative attitude and act, and that is indeed a violation of policy, which does require collaboration. If you really insist on treating Wikipedia as a battlefield, then I can't help you. Try being pleasant and cooperative. You'll get a lot further and find I'm perfectly willing to work with you.

Secondly, your edits have already been reverted using edit summaries that clearly explained why they were reverted. I was only asking out of curiosity, just in case there was some reason we should make an exception. I see no reason, but wanted to give you a chance to explain.

Thirdly, technicalities are basically immaterial here. The basic fact is that one human being isn't normally allowed to edit using more than one account. IP numbers count as separate accounts and cause confusion. Many editors, especially newbies, can easily think they are dealing with multiple people, and that is what we wish to avoid. Choose one identity and you'll be fine. Then it won't make any difference where you are located or whether your IP is dynamic or static. You'll always appear as the same person editing. That's what it all comes down to. There is no legitimate reason to not do it, while refusing to do it when warned because your actions are already viewed as disruptive will only give you a bad name. You will also gain access to more tools, rights, privileges and anonymity.

Fourth, there seems to be no reason to continue this thread, since antagonism isn't needed here. This isn't a battlefield and I'm not interested in responding to unconstructive comments. -- Brangifer (talk) 02:58, 6 July 2012 (UTC)

I do not agree with your single-handed decision to "close" this discussion without "allowing" me to respond.

Your original contention that all letters, including letters from experts, were not compliant with WP:MEDRS is not supported by WP:MEDRS itself as it only explicitly forbids non-expert letters. I originally referenced an expert letter published on a university website. You reverted citing the false claim. I then rephrased my edits and referenced two expert letters published in a scientific journal. You reverted citing the false claim. In hope of finding consensus, I then referenced a review (PMID 10336883) published in a scientific journal which basically stated the same as the preceding letters (among other things). You reverted citing no reason. What is your rationale for not accepting this review as a source? Simple edit warring can't be the case because in each revision, I adapted my edits and references. As I see it, you were the original unconstructive force.

Your edits have already been rejected by three editors here, but you are welcome to seek more input from the experts at WT:WikiProject Medicine, where we typically seek input for questions about RS on medical topics. -- Brangifer (talk) 02:06, 7 July 2012 (UTC)

All the three editors reverting my edits were referring to letters, even though my last revisions referred to a scientific review. That doesn't make sense, and it seems to me you are trying to avoid answering this very question (what's wrong with the review?). It is either abuse of power, or at least some of the editors didn't check the last reference and were simply assuming it was a letter, even though my last edit summary made clear what it was (a review, not a letter). — Preceding unsigned comment added by 80.133.47.41 (talk) 10:48, 7 July 2012 (UTC)

I can see how confusion may have occurred, since your edit summaries had been about letters, and your last one mentioned letters, but also mentioned a review. That last part might have been overlooked.

The article is protected, partially because you are IP hopping, as the edit summary says. If you want any respect here, register. Seriously, you have a lot to gain from doing so, and absolutely nothing to lose. You will never be treated with full respect as long as you edit from an IP. That may not seem fair, because not all IPs are vandals and unserious editors, but most vandals are IPs or amateurs, and their actions affect the reputation of all IP editors. That's the facts.

As to whether that review is being used properly as criticism of another study, or whether the wording is proper, is getting a bit too complicated for me to judge. All I can read is the abstract. I still suggest you seek more input from the experts at WT:WikiProject Medicine and reference this thread at the same time. That's the way forward. -- Brangifer (talk) 16:43, 7 July 2012 (UTC)

By the way, you can find the full text of the review here: http://www.fasebj.org/content/13/9/1007.full (Search for "Vitamin C exhibits pro-oxidant properties" to get to the relevant section.)

I referenced PubMed because of the convenience of the citation bot. This will be my last reply. — Preceding unsigned comment added by 80.133.48.21 (talk) 10:12, 8 July 2012 (UTC)

Thank you for that link. Much appreciated. -- Brangifer (talk) 18:33, 8 July 2012 (UTC)

I have now installed your basic content, with slightly revised wording, and pointing to the actual journal. My edit summary notes my thoughts and we'll let other editors either accept or reject it. If it gets rejected, we can discuss the matter here. -- Brangifer (talk) 20:52, 8 July 2012 (UTC)

Brangifer, you state that there is no valid reason for not having an identity on Wikipedia. If this were the case, users without accounts would not be allowed to edit pages. I have to say it certainly sounds like you are power-tripping. It takes two to get involved in an edit war, and requesting an article lock while it represents your version of reality is rather specious and not in the spirit of Wikipedia. I'm with 80.133.48.21 on this. I too have absolutely no desire to be a registered user so that I may tout my badges of honour or make virtual friends. There are an awful lot of anonymous editors who contribute significantly to Wikipedia, and your insistence on sacrificing this anonymity can only be a destructive force.

Furthermore, the source to which 80.133.48.21 refers is perfectly acceptable. A letter in a peer-reviewed scientific journal is tantamount to a paper itself in terms of credibility, and is therefore acceptable. Nature Letters are essentially shorter papers (for example). I do not understand your comment about original research - s/he finds a peer-reviewed scientific source criticising something, then cites it on Wikipedia. The only thing that is original in this case is the search for the letter itself. I challenge you to cite anything without looking for it first!?

I don't know whether you have your own agenda to promote, or just way too much time on your hands, but seriously, grow up and let the adults do the editing. 2.217.128.170 (talk) 15:29, 11 July 2012 (UTC)

Your use of the phrase "sacrificing this anonymity" reveals that you are confusing a "user account" with "a real world personal identity". I teach a college class (to students a third my age, so drop the insults) about editing Wikipedia, and I always recommend using an anonymous username and protecting one's privacy. I believe in preserving anonymity. Using an IP gives less privacy than a registered account. A registered account can be totally anonymous, and gives more rights and better access to editing privileges and tools, many of which are denied (by our rules) to IP editors.

Regardless of the fact that there are many good IP editors, IP editors generally command less respect. That's just the way it is, and neither of us can change that fact. Also, there is no obligation to use one's userpage for anything. It can remain blank if one wishes, but it's considered the mark of a newbie and is literally a red flag when looking for vandals, who often have red linked userpages. OTOH, the user talk page is used for communication with other editors, and should be used.

My agenda is to ensure that our policies are followed. You don't seem to have been following what's been happening here. I already fixed this matter on July 8, and in a manner that should be satisfactory to everyone. Take a look at the edit I made. So far it hasn't been reverted. Satisfied now? -- Brangifer (talk) 06:54, 12 July 2012 (UTC)

My personal preference is to eliminate any and all content sourced to sources that does not meet MEDRS (i.e. primary studies). Surely there are reviews discussing this in the literature, I would hope that instead of trying to go back and forth using one primary study to try to debunk another, that we just use high quality reviews instead. Yobol (talk) 16:16, 11 July 2012 (UTC)

For controversial content I tend to agree. It would be nice to find it before deleting what we have, so we replace it with something more in line with MEDRS. -- Brangifer (talk) 14:37, 12 July 2012 (UTC)

^ Linster, Carole (December 12, 2006). "Vitamin C: Biosynthesis, recycling and degradation in mammals". Retrieved 2007-04-30. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)CS1 maint: date and year (link)
^ Higdon, Jane. "Linus Pauling Institute Recommendations". Oregon State University. Retrieved 2007-04-11. {{cite web}}: Cite has empty unknown parameters: |month= and |coauthors= (help)
^ Roc Ordman. "The Scientific Basis Of The Vitamin C Dosage Of Nutrition Investigator". Beloit College. Retrieved 2007-02-22.
^ "Vitamin C Foundation's RDA". Retrieved 2007-02-12.
^ Levy, Thomas E. (2002). Vitamin C Infectious Diseases, & Toxins. Xlibris. ISBN 1401069630. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help) Chapter 5 - Vitamin C optidosing.
^ Pauling, Linus (1986). How to Live Longer and Feel Better. W. H. Freeman and Company. ISBN 0-380-70289-4.
^ S.C. Rumsey and M. Levine, Nutritional Biochemistry, 9:116-30 (1998).
^ "Vitamin C (Ascorbic acid)". MedLine Plus. National Institute of Health. 2006-08-01. Retrieved 2007-08-03.
^ Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2008). "Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases". Cochrane Database Syst Rev (2): CD007176. doi:10.1002/14651858.CD007176. PMID 18425980.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Huang, Han-Yao; Caballero, Benjamin; Chang, Stephanie; Alberg, Anthony J.; Semba, Richard D.; Schneyer, Christine; Wilson, Renee F.; Cheng, Ting-Yuan; Prokopowicz, Gregory; Barnes, George J. II; Vassy, Jason; Bass, Eric B. (2006). "Multivitamin/mineral supplements and prevention of chronic disease". Evid Rep Technol Assess (Full Rep) (139): 1–117. PMID 17764205. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ Brzozowska A, Kaluza J, Knoops KT, de Groot LC (2008). "Supplement use and mortality: the SENECA study". Eur J Nutr. 47 (3): 131–7. doi:10.1007/s00394-008-0706-y. PMID 18414768. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
^ Heiner, Kathryn A; Hart, Ann Marie; Martin, Linda Gore; Rubio-Wallace, Sherrie (2009). "Examining the evidence for the use of vitamin C in the prophylaxis and treatment of the common cold". Journal of the American Academy of Nurse Practitioners (21): 295–300. doi:10.1111/j.1745-7599.2009.00409.x. PMID 19432914.
^ Sasazuki, S; Sasaki, S; Tsubono, Y; Okubo, S; Hayashi, M; Tsugane, S (2005). "Effect of vitamin C on common cold: randomized controlled trial". European Journal of Clinical Nutrition. 60 (1): 9–17. doi:10.1038/sj.ejcn.1602261. PMID 16118650.
^ Hemilä, Harri; Chalker, Elizabeth; Douglas, Bob; Hemilä, Harri (2007). "Vitamin C for preventing and treating the common cold". Cochrane database of systematic reviews (3): CD000980. doi:10.1002/14651858.CD000980.pub3. PMID 17636648.

[1] Linster, Carole (December 12, 2006). "Vitamin C: Biosynthesis, recycling and degradation in mammals". Retrieved 2007-04-30. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)CS1 maint: date and year (link)

[2] Higdon, Jane. "Linus Pauling Institute Recommendations". Oregon State University. Retrieved 2007-04-11. {{cite web}}: Cite has empty unknown parameters: |month= and |coauthors= (help)

[3] Roc Ordman. "The Scientific Basis Of The Vitamin C Dosage Of Nutrition Investigator". Beloit College. Retrieved 2007-02-22.

[4] "Vitamin C Foundation's RDA". Retrieved 2007-02-12.

[5] Levy, Thomas E. (2002). Vitamin C Infectious Diseases, & Toxins. Xlibris. ISBN 1401069630. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help) Chapter 5 - Vitamin C optidosing.

[Pauling_book-6] Pauling, Linus (1986). How to Live Longer and Feel Better. W. H. Freeman and Company. ISBN 0-380-70289-4.

[7] S.C. Rumsey and M. Levine, Nutritional Biochemistry, 9:116-30 (1998).

[8] "Vitamin C (Ascorbic acid)". MedLine Plus. National Institute of Health. 2006-08-01. Retrieved 2007-08-03.

[Cochrane08-9] Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2008). "Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases". Cochrane Database Syst Rev (2): CD007176. doi:10.1002/14651858.CD007176. PMID 18425980.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[Huang-10] Huang, Han-Yao; Caballero, Benjamin; Chang, Stephanie; Alberg, Anthony J.; Semba, Richard D.; Schneyer, Christine; Wilson, Renee F.; Cheng, Ting-Yuan; Prokopowicz, Gregory; Barnes, George J. II; Vassy, Jason; Bass, Eric B. (2006). "Multivitamin/mineral supplements and prevention of chronic disease". Evid Rep Technol Assess (Full Rep) (139): 1–117. PMID 17764205. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[pmid18414768-11] Brzozowska A, Kaluza J, Knoops KT, de Groot LC (2008). "Supplement use and mortality: the SENECA study". Eur J Nutr. 47 (3): 131–7. doi:10.1007/s00394-008-0706-y. PMID 18414768. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

[Heimer2009-12] Heiner, Kathryn A; Hart, Ann Marie; Martin, Linda Gore; Rubio-Wallace, Sherrie (2009). "Examining the evidence for the use of vitamin C in the prophylaxis and treatment of the common cold". Journal of the American Academy of Nurse Practitioners (21): 295–300. doi:10.1111/j.1745-7599.2009.00409.x. PMID 19432914.

[13] Sasazuki, S; Sasaki, S; Tsubono, Y; Okubo, S; Hayashi, M; Tsugane, S (2005). "Effect of vitamin C on common cold: randomized controlled trial". European Journal of Clinical Nutrition. 60 (1): 9–17. doi:10.1038/sj.ejcn.1602261. PMID 16118650.

[Hemilä2010-14] Hemilä, Harri; Chalker, Elizabeth; Douglas, Bob; Hemilä, Harri (2007). "Vitamin C for preventing and treating the common cold". Cochrane database of systematic reviews (3): CD000980. doi:10.1002/14651858.CD000980.pub3. PMID 17636648.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]