Talk:Vitamin C

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Good article Vitamin C has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do. If it no longer meets these criteria, you can delist it, or ask for a reassessment.
To-do list for Vitamin C: edit · history · watch · refresh

Here are some tasks you can do:
  • Copyedit: the section order relating to its content
  • Wikify: fix red links! either create the article from what information you can gather, or, as a last resort, remove the link
  • Cleanup:
    the references, adding any requested citations and using {{cite web}}, {{cite journal}}, {{cite book}} or {{cite news}} wherever possible
    "ascorbic acid" should only be referred to when specifically discussing that chemical, otherwise use "vitamin C" or "ascorbate"
    ensure information is not being repeated
  • NPOV: please try to ignore personal bias and focus intently on maintaining neutrality between the views of megadosers and non-megadosers
  • Other:
    consider splitting any large sections to their own article
    keep article size down (without sacrificing any vital info)
    remove "see also" section - should be incorporated into the article proper
    See for further recommendations for improvement the comments made on the wikiproject notices
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[edit] More pseudoscience

"Alternative medicine" is double-speak. If it is not medicine, then it cannot be called medicine. I am changing "alternative medicine" to "alternatives to medicine" to emphasize that "orthomedicine" is not medicine. An encyclopedia is not a forum for pseudoscientists to use double-speak to make their quackery sound legitimate. —Preceding unsigned comment added by 24.126.151.171 (talk) 06:04, 16 March 2008 (UTC)

I don't fully understand why you chose to talk about this topic. Is it a response to something? Is it in the article anywhere?
You should really make new comments at the end of the discussion not the top as it is generally the accepted place to put new posts in the discussion page.
On the topic of your comment I can't see why anyone using the phrase "alternative medicine" could be accused of being a "pseudo-scientist". I study pharmacy and while that doesn't make me a doctor or a scientist in the strictist sense I am more than familiar with medicines.
All lectures touching on the subject refer to term "alternative medicine". It is generally the accepted usage of the term.
Maybe it's a matter of opinion but anyone working in health care that I have worked with has referred to it as alternative medicine, regardless of whether they are working in the more typical medical setting or the alternative field.
Maybe it is double-speak and I am giving more credit than is due and I will admit I have strong opinions against homeopathy (other branches to me have more credability), but I don't think it is designed to mislead.
I also don't think categorically denying it on a seemingly random talk page on Wikipedia will have any effect on the way people will use the term. Why not go to the Alternative medicine talk page as it will have more imact there. Medos (talk • contribs) 16:57, 16 March 2008 (UTC)

[edit] Pseudoscience

The evolutionary claims advanced by Mathhias Rath have no bearing in science whatsoever. Giving him an entire paragraph in this article lends him undue respectability.Can you imagine an article on the element mercury say, with a paragraph about the controversial doctor-x who theories that evolutionary deficiencies of it result in tennis elbow or some such nonsense. This article is replete with dubious nutrition as it is,without adding spurious evolutionary theories into the mix.Im removing the mathias paragraph for this reason.If people want to read about his crack pot theories they can look him up in his main article. Gerfinch 16:51, 21 June 2007 (UTC)


[edit] C Vitamin

Another indication (proof) of the myopia, insolence, and arrogance of the contributors from the Land of Intelligent Design: not only is this article incorrectly called 'Vitamin C' instead of 'C Vitamin' but THERE IS NO REDIRECT from 'C Vitamin' either. It's time people with this lack of savvy retired from Wiki. —The preceding unsigned comment was added by 62.1.114.104 (talk) 16:04, 19 March 2007 (UTC).

Just created the redirect now :P ...although, I'm not totally sure it was needed — Jack · talk · 05:29, Wednesday, 21 March 2007
And GOD spoke, and C, there was a vitamin? Sorry, the pun's so bad, had to get rid of it :) 199.74.98.127 04:03, 27 April 2007 (UTC)

[edit] About the opening sentence

The article begins with: "Vitamin C ... is an essential nutrient required in small amounts" When we read the rest of the article, we realize that what small means is actually the root of the debate on vitamin C (emphacized two sentences later). Small amounts, yes: smaller than protein, lipids, and sugars, yes. But as small as other vitamins? It would be partial (biased) to let this be suggested. The reference provided in the section "Natural mode of synthesis" [1] :

Milton, K. (1999) "Nutritional characteristics of wild primate foods: do the diets of our closest living relatives have lessons for us?" Nutrition. 1999 Jun;15(6):488-98.

which supports:

Most simians (higher primates who cannot produce vitamin C) consume the vitamin in amounts 10 to 20 times higher than that recommended by governments for humans.

Has its importance. If we accept that vitamin will mean "small amounts" in this case as well, without perceiving the very problem caused by this choice of words, we are not neutral. I would suggest something like the following: instead of:

Vitamin C or L-ascorbic acid is an essential nutrient required in small amounts in order to allow a range of essential metabolic reactions in animals and plants. Vitamin C is widely known as the vitamin that prevents scurvy in humans.[1][2][3] The joint US-Canadian Dietary Reference Intake recommends 90 milligrams per day and no more than 2 grams per day (2000 milligrams per day),[4] although the amount that humans require for optimum health is a matter of on-going debate.

I suggest:

Vitamin C or L-ascorbic acid is essential to allow a range of essential metabolic reactions in animals and plants. The unability to produce vitamin C (gulonolactone oxidase deficiency) is rare(ref avail.). It is shared by all great apes/primates/simians, including humans. The former consume vitamin C in amounts 10 to 20 times higher than what the latter consume. The amount that humans require is a matter of on-going debate. Vitamin C is most widely known as the vitamin, which, in small amounts, prevents scurvy.[1][2][3]

The following research, which also summarizes earlier results by others, poses well the problem that we are facing when speaking of vitamin C: Comp Biochem Physiol A Mol Integr Physiol. 2003 Sep;136(1):47-59.

Micronutrient intakes of wild primates: are humans different?

Milton K.


Department of Environmental Science, Policy and Management, Division Insect Biology, University of California, Berkeley, CA 94720-3112, USA. kmilton@socrates.berkeley.edu

Low micronutrient intake is implicated in a diversity of human health problems, ranging from problems associated with food insufficiency to those associated with food over-consumption. Humans are members of the order primates, suborder anthropoidea, and are most closely related to the great apes. Humans and apes are remarkably similar biologically. In the wild, apes and monkeys consume diets composed largely of plant foods, primarily the fruits and leaves of tropical forest trees and vines. Considerable evidence indicates that the ancestral line giving rise to humans (Homo spp.) was likewise strongly herbivorous (plant-eating). The wild plant parts consumed by apes and monkeys show moderate to high levels of many minerals and vitamins. The estimated daily intake of specific minerals, vitamin C and some other vitamins by wild primates is often quite high in comparison to intake levels of these same micronutrients recommended for humans. Are the high micronutrient intakes of wild primates simply a non-functional, unavoidable by-product of their strongly plant-based diets or might they actually be serving important as yet undetermined immunological or other beneficial functions? A better understanding of the basis for this apparent difference between humans and wild primates could help to clarify the range and proportions of micronutrients best suited for optimal human development, health and longevity. PMID: 14527629 [PubMed - indexed for MEDLINE]

FULL TEXT: http://nature.berkeley.edu/miltonlab/pdfs/kmilton_micronutrient.pdf

Any ideas on how to improve on fairness ? Pierre-Alain Gouanvic 07:12, 11 March 2007 (UTC)

Please see my addition to this Talk page, below, to see some comments on this issue. Antelan talk 22:36, 23 March 2007 (UTC)

[edit] Chemotherapy interaction

Moved uncited, oversimplified stmt here for discussion, improvement, and references. "Additonally, high doses of Vitamin C can reduce the effectiveness of chemotherapy as the Vitamin C neutralizes some of the free radicals generated by the chemotherapy intended to destroy malignant cells."--TheNautilus 04:14, 26 December 2006 (UTC)

Normally, vitamin C is used by the immune system to create free radicals in order to kill cancer cells. (See the book Ascorbate by Hickey) --Coppertwig 12:26, 20 February 2007 (UTC)

[edit] How many Vitamin C biosynthesis enzymes do humans have? Two or three?

The section "Vitamin C hypothesis" has this sentence: The fact that man possesses three of the four enzymes that animals employ to manufacture ascorbates in relatively large amounts, has led researchers such as Irwin Stone and Linus Pauling to hypothesize that... is this factually correct? As far as I know, most humans actually have two, instead of three, enzymes that play a part in the biosynthesis pathway. All humans lack l-gulonolactone oxidase due to the GULOP mutation. However humans who have only this mutation can still produce enough Vitamin C to stave off scurvy, i.e. at least 15mg. But 70% of humans also lack the lactonase enzyme that starts off the biosynthesis chain, and hence cannot produce any Vitamin C at all, thus being susceptible to scurvy. Source: http://centernet.okstate.edu/students/electives/nutrition/vitamin_c.cfm

Is this correct? And if it is, shouldn't the page be edited to reflect that? Added by User:Shernren 13:54, 3 January 2007 (unsigned at the time)

These claims are very interesting. I have not seen it claimed anywhere else that around 15% of humans can still synthesise some vitamin C . As this paper is unsourced , unattributed and is in a Student area of the site, I would like to see other references before its added to the article. It could be someones original pet theory. Lumos3 14:01, 16 January 2007 (UTC)

This hypothesis appears to be untrue. See link. TimVickers 01:53, 12 March 2007 (UTC)

[edit] Contraindications Section

In the contraindications section, it states that deficiency of a particular enzyme can make a person prone to anemia, and that it can be exacerbated by consumption of things that induce oxidizing stress. It then goes on to imply that consumption of high doses of Vitamin C should be avoided for this reason in persons with this condition.

This makes absolutely no sense. Vitamin C is a reducing agent, not an oxidizing agent. If anything, it should be used to treat the condition.

--Uberhobo 01:26, 30 January 2007 (UTC)

[edit] Importance of Vitamin C to the Body?

I can't help but be curious, is there anything in this article that goes over this, even briefly? I know it prevents scurvy, and helps certain diseases or whatever, but other than that what does it do to help the human body? I'm in 10th grade doing a Biology paper, and one of the questions I had to answer was the importance of Vitamin C to the body, which isn't in my notes, and I can't find the section for it in my textbook. I could just write down that it prevents scurvy, but that's my answer to the next question 'what might result if we have a deficiency of Vitamin C?'. If I somehow missed it in the article, I'm sorry for that. But if I did, and it was there, I don't know how reliable this article could be if I couldn't even find it with the index or my skimming.

I'm not entirely sure of all the uses (there are a few), but by far the most important one is that Vitamin C is an essential cofactor required for the production of collagen, which happens to be the human body's most prevalent protein. Collagen is a hugely important structural component found in skin, bones, blood vessels, fibrous tissue, cartilage and hair. So, I guess you could say that without Vitamin C, we literally fall apart! It's in the article, but in a very obscure place; I'll try and sort that out - Jack · talk · 22:06, Monday, 19 February 2007
I have restored the Functions in the Body section which appears to have been deleted by a vandal (Ip 195.194.218.251) last 14th November and somehow gone unnoticed. Lumos3 22:37, 19 February 2007 (UTC)
Thanks for that, (despite the edit conflict :P) I was trying to sum that up but failing miserably. I changed the section header levels back to how they were, I feel it looks better this way - Jack · talk · 22:48, Monday, 19 February 2007

[edit] 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

[edit] facts, not advice

Wikipedia is supposed to be a compendium of facts, not advice or instructions. This sentence needs to be deleted or modified: "Patients with a predispostion to form oxalate stones[citation needed] or those on hemodialysis[1][2] should avoid excess use of vitamin C.[citation needed]". Besides, I disagree: for some such people, there may be a strong reason to take large amounts of vitamin C which might outweigh the concern expressed here. This sentence can be deleted or can be replaced with a sentence along the lines of "such-and-such institution recommends that ...". --Coppertwig 14:01, 22 February 2007 (UTC)

I see it's been changed to a NPOV statement. Thanks! --Coppertwig (talk) 14:16, 26 December 2007 (UTC)

[edit] racemic mixture?

The article currently claims, in the Biological significance section, Commercial vitamin C supplements contain a racemic mixture of both enantiomers of ascorbate, with both existing as a mix of ascorbic acid and mineral ascorbates. This statement seems to have been added by User:Jrockley on Feb. 19. I don't think it's true. I think vitamin C is normally synthesized as l-ascorbic acid and sold as such. It says later in the article that vitamin C is synthesized from glucose. Glucose is chiral, so that would tend to suggest that the vitamin C synthesized in that way would also be chiral. Small amounts of d-ascorbate being present (as claimed in the previous version) is different from a "racemic" mixture of equal amounts of both enantiomers. --Coppertwig 13:09, 26 February 2007 (UTC)

No, I don't have a source for that, and the source given doesn't state that. I just didn't think my statement through, and the source is probably an archaic reminant.
I think it's safe to assume that if Vitamin C is chemically produced, it will form equally in both forms, and if the undesirable form shows no biological activity, it'll be left in (see the thalidomide article) as that is cheaper. However, if the vitamin C is biologically produced (with enzymes) you're absolutely right, only the L form will be produced and sold. Probably best not to state either, without a source. Feel free to do as you will - Jack · talk · 14:21, Monday, 26 February 2007
Thanks. OK, I took out the part about racemic mixture. The footnote attached to that sentence (end of 2nd paragraph of Biological significance; link to "Vitamin C -- risk assessment") probably needs to be moved. It's probably a useful reference, but probably has little or nothing to do with the sentence it's attached to. Maybe to be moved to the bibliography, or attached to a different sentence. I'm not sure where to put it so I may leave it where it is -- maybe it supports various stuff said in that section. --Coppertwig 13:43, 27 February 2007 (UTC)

[edit] Prooxidant effects

Should this article contain some information on the pro-oxidant effects of vitamin C? Here is a review on this topic for a starting-point. TimVickers 20:07, 7 March 2007 (UTC)

I'd be interested to see what you write. Is it controversial? I thought vitamin C was an antioxidant, or can it be both? Perhaps you could draft it here, or just be WP:BOLD? — Jack · talk · 18:54, Thursday, 8 March 2007

[edit] Suggestions

Here are my minor suggestions:

  • "This article describes its biological functions..." - an article mustn't contain such a sentence
  • This reference: Milton, 1999 should be expanded should be referenced properly as I found it at the end of the Reference section

My main problem is that whether we should include dose related information in a medical article. BTW, a well-referenced, well-structured article. NCurse work 21:23, 8 March 2007 (UTC)

Thanks :) I've implemented your minor change suggestions, and I've previously tried removing all of the dosage info here (to split into vitamin C megadosage), and here is where I added back a short summary. Do you think I re-added too much? — Jack · talk · 22:07, Thursday, 8 March 2007
Thank you, it seems to be good. Only one: It has been hypothosised that the vitamin can protect against: is it surely important? NCurse work 16:33, 9 March 2007 (UTC)

I don't know, I thought it would be a good example of the suggestions made by megadosers. If you have a look at Vitamin_C_megadosage#Therapeutic_applications_of_high_doses, you'll see that...

It has been hypothesised that the vitamin can prevent and cure a wide range of common and/or lethal diseases, ranging from the common cold and cataracts to controversial statements involving it being a cure for AIDS SARS and bird flu. There have even been suggestions that vitamin C can cure lead poisoning and autism.

...is a very trimmed down version. I don't think it is particularly biased in anyway, and you could interpret it as "yes, us megadosers suggest that" or "ha! look at what those crazy megadosers are suggesting", and it is clearly important to the subject of the article. What would you include? Perhaps we could drop the last sentence — Jack · talk · 19:02, Friday, 9 March 2007

[edit] GA on hold

Please take care of the {{fact}} tags.--Rmky87 17:24, 9 March 2007 (UTC)

Done :) was that the only thing holding it back from GA status? — Jack · talk · 19:49, Friday, 9 March 2007
As far as I could see, yes.--Rmky87 05:15, 10 March 2007 (UTC)
You should move ref#10 to the end of the sentence.--Rmky87 14:03, 11 March 2007 (UTC)

[edit] GA Pass

I am going ahead and passing this article as the {{fact}}s have been taken care of. This article needs the gaps to be fixed, the external link cleanup to happen, and some repetitive information that needs to be dealt with. As soon as this happens, I would recommend nominating it for Featured Article status.--JEF 03:09, 13 March 2007 (UTC)

^_^ yay! Thankyou! I'll get right on it. Only, could you specify what you mean by "gaps"? — Jack · talk · 05:41, Monday, 12 March 2007
The blank spaces. Nothing too serious; it takes seconds.--JEF 03:09, 13 March 2007 (UTC)
I've taken a shot at removing possible whitespace causes here, although it doesn't seem to have made much difference to me. Blankspaces depend largely on screensize, font, textsize, your personal thumbnail choice etc. I see no spaces, besides unavoidable ones surrounding the food summary tables. Any information about the way others see the article would help. — Jack · talk · 06:35, Tuesday, 13 March 2007

I went ahead and did it myself. Look here to see how I did it.--JEF 00:32, 14 March 2007 (UTC)

Still looks the same to me. Yeah, I wouldn't have been able to fix that, I never saw any whitespace. But if it fixes it for some people, great! Thanks for that — Jack · talk · 11:47, Wednesday, 14 March 2007

[edit] Curing the Incurable: Vitamin C, Infectious Diseases, and Toxins

Dr. Thomas Levy's Curing the Incurable: Vitamin C, Infectious Diseases, and Toxins has been removed because it is already cited in the notes. (#39, for the moment) There is no need to repeat the book's name in the reference section. --BorgQueen 22:56, 16 March 2007 (UTC)

[edit] To shorten the length of the article

Hi colleagues! For now on, I'll try to edit parts of this article that seem too wordy. I'll write "wordy" each time I think I encounter occurences of such problems. I intend to meet the challenge of having a concise and dense article for such an immense topic. If I sacrifice too much (I'll be very cautious), do not hesitate to revert! Pierre-Alain Gouanvic 06:07, 18 March 2007 (UTC)

Thanks for your help. Although, I still think maintaining absolute neutrality is still your sticking point — Jack · talk · 03:36, Wednesday, 21 March 2007
Yes, and care must be taken to leave the necessary room for all points of views. Pierre-Alain Gouanvic 15:38, 21 March 2007 (UTC)

[edit] Questionable carnitine statement

"Two other vitamin C dependent enzymes are necessary for synthesis of carnitine."

I believe that only one vit. c - dependent enzyme is involved in carnitine synthesis (the first, I believe, to add an hydroxyl). This should be checked and the reference should be refreshed. Some open access documents must exist. Pierre-Alain Gouanvic 06:34, 18 March 2007 (UTC)

I was wrong: Am J Clin Nutr. 1991 Dec;54(6 Suppl):1147S-1152S.
Ascorbic acid and carnitine biosynthesis.
* Rebouche CJ.
It has been suggested that early features of scurvy (fatigue and weakness) may be attributed to carnitine deficiency. Ascorbate is a cofactor for two alpha-ketoglutarate-requiring dioxygenase reactions (epsilon-N-trimethyllysine hydroxylase and gamma-butyrobetaine hydroxylase) in the pathway of carnitine biosynthesis. Carnitine concentrations are variably low in some tissues of scorbutic guinea pigs. Ascorbic acid deficiency in guinea pigs resulted in decreased activity of hepatic gamma-butyrobetaine hydroxylase and renal but not hepatic epsilon-N-trimethyllsine hydroxylase when exogenous substrates were provided. It remains unclear whether vitamin C deficiency has a significant impact on the overall rate of carnitine synthesis from endogenous substrates. Nevertheless, results of studies of enzyme preparations and perfused liver in vitro and of scorbutic guinea pigs in vivo provide compelling evidence for participation of ascorbic acid in carnitine biosynthesis. PMID: 1962562
Pierre-Alain Gouanvic 18:43, 18 March 2007 (UTC)

[edit] Glycogen specifying

The vast majority of animals and plants are able to synthesize their own vitamin C, achieved through a sequence of four enzyme driven steps, which convert glucose to vitamin C.

It is important to specify that glycogen is actually the primary substrate. There is no direct glucose-to-ascorbate pathway. I encourage others to check it out. I'll find the references anyways. Pierre-Alain Gouanvic 06:40, 18 March 2007 (UTC)

[edit] Therapeutic uses section

Hi, I have moved the "Therapeutic applications of high doses" section away from the "vitamin c as a macronutrient" section because I understand nutritional and pharmacologic considerations to be different things. This change was reverted on the basis of neutrality. I don't perceive that this can be supported. Have I missed something? Pierre-Alain Gouanvic 06:18, 22 March 2007 (UTC)

[edit] About the title section "History of human understanding"

At first glance, I found this title to be a little redundant. A Web search shows that this phrase is used is similar contexts. I apologize for the hasty removal. Pierre-Alain Gouanvic 06:23, 22 March 2007 (UTC)

[edit] NPOV in first paragraph

The first paragraph is subtle, but induces bias for a person not already familiar with Vitamin C. A particularly precarious sequence is the following:

The North American Dietary Reference Intake recommends 90 milligrams per day and no more than 2 grams per day (2000 milligrams per day).[6] Other related species sharing the same inability to produce vitamin C and requiring exogenous vitamin C consume 20 to 80 times this reference intake.

The first statement is sourced and uncontroversial. The second sentence is unsourced, and needs support to be considered valid. From my experience with this material, I am confident someone will be able to find a peer-reviewed or otherwise acceptable source to back up this statement. Nevertheless, the juxtaposition of these two sentences leads the reader to question why the NADRI is 20 to 80x below what it is for other species. The inevitable conclusion is that the NADRI is set too low. This is a controversial point; as can be seen in Reference 24, there are thought to be evolutionary reasons behind the decreased need for vitamin C (involving uric acid). Glutathione and other molecules are also believe to fulfill similar antioxidant roles. As it stands, readers are not exposed to this additional information, and merely see that humans are getting 1/80th as much Vitamin C as do similar species.

Therefore, I propose that either:

  1. A sentence be added, with references, saying something along the lines of However, it has been hypothesized that uric acid and glutathione have taken on many of the roles of Vitamin C in humans; or,
  2. The second sentence referenced above simply be removed as it is not a major contributory point of this article.

Any thoughts on the matter? --Antelan talk 22:29, 23 March 2007 (UTC)

The paragraph also states that "its uses and requirements are matters of on-going debate" . Either the debate around vitamin C is not mentioned or some allusion to its nature must be made. Vitamin C is the only vitamin where there is a continuing debate within the scientific community and I believe this needs to be said at the opening. Therefore some form of words which describe it are needed in order to give a hint of its nature. Either we point to higher consumption levels in non ascorbic acid synthesisers or we mention that most organisms produce it endogenously in what must be considered vast amounts. Lumos3 01:32, 24 March 2007 (UTC)
Those are actually two different ways of proffering the same point of view, not two halves of the issue. Because we mention that other non-ascorbic-acid synthesizers consume Vitamin C in higher amounts than humans, therefore we should also present the other half of the issue - that there is evidence pointing to compensatory mechanisms that account for our decreased requirements. Antelan talk 01:42, 24 March 2007 (UTC)
The controversy is exactly that. Megadose proponents say the primates rely on fragile systems of second best molecules like uric acid and an essential fruit diet to perform a range of body functions. The original mammalian model they evolved from on the other hand self metabolises the ascorbate molecule in what seem to us vast amounts. The metabolic pathways for the ascorbate molecule are still there within the primates waiting to be utilised. Megadose proponents say our systems are broken and have picked up a range of patches to get by. Skeptics believe this patched system is the optimum one. Some kind of summary of these different views needs to appear in the introduction. Lumos3 23:09, 24 March 2007 (UTC)
In addition, it is justified to mention the intake of primate relatives because, in fact, primate dosers and non-primate dosers (I'wont use the term megadosers, it is not neutral, just like the term vitamin is not neutral), both sides of the controversy, agree on the following (quoted from the authoritative Online Mendeleian Inheritance in Man, but also agreed upon by Pauling):
The mechanism whereby an organism loses a particular metabolic function which is of no use in a particular environment was discussed by King and Jukes (1969). The accumulation of random mutations in the gene for the relevant enzyme might be expected to destroy the functional capacity of the enzyme, most mutations being disruptive. If the enzyme is not required in the particular environment, the constraint of selection is removed. Primates and the guinea pig, by this hypothesis, have lost the capacity to synthesize ascorbic acid because of the adequacy of dietary intake.
So what is this adequate dietary intake? What's mentioned here. It might be seemingly biased to state the facts but... it isn't! (of course)
I would add that those "second best molecules" are not well identified yet; uric acid is one candidate, yes, but lipoprotein(a) is another (more convincing one to me); there also exists a view according to which viruses, more specifically retroviruses, might have played an active role in human evolution, i.e. that such pathogens, considered higher in species not producing ascorbate, accelerated mutation rates and the selection of new, favourable traits in humans (but I don't remember well, I should get the ref.).
To be straightforward, I don't think that non-primate dosers support their views (that we need no more than 200 mg per day) with such rationales. I don't think that they generally mention uric acid or lp(a). Really. I read a lot of this, and what I consistently found is references to pharmacokinetic studies (correctly analyzed elsewhere in the article) suggesting that more than 200 mg a day is just "expensive urine".
I thus find questionable to add urate or lp(a) or glutathione, etc, to support the views of non-primate dosers while those molecules were actually brought and discussed by primate dosers who, contrary to non-primate dosers, felt that they had to understand how primates can live without endogenous ascorbate (mammalian doses, if I may).
To avoid any appearances of non-NPOV and to enrich the article, I would summarize this quote above in order to appropriately introduce the sentence on primate intakes. Pierre-Alain Gouanvic 07:18, 25 March 2007 (UTC)
For greater neutrality, the single contested sentence could just be removed from the introduction, since the controversy is already alluded to in another introductory sentence. I think this is the preferable solution, since alluding to the controversy should be substantial enough for the intro paragraph; the conflicted viewpoints need not be elaborated until the body of the article. Antelan talk 17:35, 25 March 2007 (UTC)
What contested sentence? Pierre-Alain Gouanvic 03:24, 26 March 2007 (UTC)
The sentence around which our discussion has been revolving. Antelan talk 04:51, 26 March 2007 (UTC)
The sentence is now sourced. Please engage in the discussion. Pierre-Alain Gouanvic 05:23, 26 March 2007 (UTC)
The sentence has been sourced even since before I lodged my complaint. It's now double sourced. Read my discussion again; I'm concerned that it introduces bias; even supported sentences, when placed and worded in a certain way, can introduce POV. See WP:NPOV for more on that. See the discussion above for my suggestions on how to correct this. Antelan talk 18:04, 26 March 2007 (UTC)
Before going further. You say: "The sentence has been sourced even since before I lodged my complaint." But after reading, again, the discussion, I am puzzled: you said "The second sentence is unsourced, and needs support to be considered valid." Pierre-Alain Gouanvic 23:18, 27 March 2007 (UTC)
Yes, forgive me for the timeline: sources have been added since I began the discussion. However, my statment was as follows: From my experience with this material, I am confident someone will be able to find a peer-reviewed or otherwise acceptable source to back up this statement. Nevertheless... As you can see, I fully agreed from the outset that the statement would easily find a source to back it up - nevertheless, that is not even close to the point of my entire discussion. It's a strawman. Please read above and you'll see that NPOV is the core of my concern, not the sourcing of one sentence. Antelan talk 20:01, 28 March 2007 (UTC)
I have made the change - a single copy and paste - in order to put both (1) the RDA statement and (2) the megadose statement into their proper context, removing them from the introductory paragraph and leaving the briefer and more neutral introductory statement indicating that there is controversy. Antelan talk 05:57, 29 March 2007 (UTC)

[edit] Fact Check

The article currently contains this claim: Goats, like almost all animals, make their own vitamin C. An adult goat will manufacture more than 13,000 mg of vitamin C per day in normal health and as much as 100,000 mg daily when faced with life-threatening disease, trauma or stress. There is a source given for this claim, but it does not support, or even mention, the 100,000 mg/day figure. Can a stressed goat really pump out 100 grams (3.5 ounces) of pure Vitamin C every 24 hours? This sounds quite extraordinary so it would be great to have an actual source for this claim. —The preceding unsigned comment was added by 125.238.204.46 (talk) 07:51, 6 April 2007 (UTC).


The best source I can find for this is a 1978 paper by Irwin Stone enttled Eight Decades of Scurvy. The Case History of a Misleading Dietary Hypothesis. He cites the work of two earlier researchers, Chatterjee, and Subramanian. [2]

Biochemical research in the 1950’s showed that the lesion in scurvy is the absence of the enzyme, L-Gulonolactone oxidase (GLO) in the human liver (Burns, 1959). This enzyme is the last enzyme in a series of four which converts blood sugar, glucose, into ascorbate in the mammalian liver. This liver metabolite, ascorbate, is produced in an unstressed goat for instance, at the rate of about 13,000 mg per day per 150 pounds body weight (Chatterjee, 1973). A mammalian feedback mechanism increases this daily ascorbate production many fold under stress (Subramanian et al., 1973).
Lumos3 10:47, 6 April 2007 (UTC)
I've gone through a handful of the other sources and updated the article to read what the sources actually claimed, which in many cases was quite different from what was stated in this article. It's a bit spooky that even some of the sourced statements are untrue to their sources. Antelan talk 21:17, 9 April 2007 (UTC)
I imagine that's quite common with community built resources. Perhaps someone added a source to give credibility to their OR, hoping no-one will see it? Well done for spotting that, btw :) — Jack · talk · 03:11, Monday, 16 April 2007
Thanks, Jack. I've also removed another statement: The implication of those calculations, if correct, is that vitamin C was misnamed as a vitamin and is in fact a vital macronutrient like protein or carbohydrate. I removed this because it was not sourced, and the Wikipedia article on macronutrients defines them as being required to provide energy, not just being required for health. That article is not sourced, either; if that article incorrectly defines macronutrients, by all means it should be corrected and this sentence could be reinserted into this article. Antelan talk 03:45, 17 April 2007 (UTC)

[edit] 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. Antelan 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! Antelan 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)

[edit] 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)

[edit] 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. Antelan 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. Antelan 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. Antelan 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. Antelan talk 20:35, 18 June 2007 (UTC)

[edit] 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)

[edit] 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)

[edit] 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.[3] 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)

[edit] 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)


[edit] 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. Antelan talk 21:12, 2 August 2007 (UTC)

[edit] 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)

[edit] Esther C? Non-acid vitamin C?

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

[edit] recommended intakes somewhat nonsensual

[edit] 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:

  • 500 milligrams per 12 hours: Professor Roc Ordman, from research into biological free radicals.[5]
  • 3,000 milligrams per day (or up to 300,000 mg during illness): the Vitamin C Foundation.[6]
  • 6,000–12,000 milligrams per day: Thomas E. Levy, Colorado Integrative Medical Centre.[7]
  • 6,000–18,000 milligrams per day: Linus Pauling's personal use.[8]

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)

[edit] 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)

[edit] 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)

[edit] 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)


[edit] 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)

[edit] 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.

  1. "Once absorbed, ascorbic acid has a short in vivo half-life of approximately 30 minutes."
  2. [3]: A key study in support of high dosages, I think. Also makes the 30-minute half-life claim.
  3. "For man the half-life varied from thirteen to thirty days depending on the daily dietary intake of ascorbic acid."
  4. 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)

[edit] 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)