Talk:Vitamin C

Removed during Big Cleanup

Image:Ascorbic_acid.png|right|frame|Chemical structure of vitamin C

Image:Ascorbic-acid-3D-vdW.png|thumb|right|200px|Model of the vitamin C (L-ascorbic acid) molecule. Black is carbon, red is Oxygen and white is Hydrogen

Image:GyorgyiNIH.jpg|thumb|200px|right|Albert Szent-Györgyi, pictured here in 1948, was awarded the 1937 Nobel Prize in Medicine for the discovery of vitamin C

Image:Rosa canina hips.jpg|right|thumb|Rose hips are a particularly rich source of vitamin C

Image:Goat.jpg|thumb|250px|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.

Image:RedoxonVitaminC.jpg|thumb||right|Vitamin C is widely available in the form of tablets and powders. The Redoxon brand, produced by Hoffmann-La Roche was the first mass-produce synthetic vitamin C and was launched in 1934.

Pierre-Alain Gouanvic 00:05, 20 November 2007 (CST)Image:Ambersweet oranges.jpg|right|thumb|Citrus fruits were one of the first sources of vitamin C available to ship's surgeons.

Image:James lind.jpg|180px|right|thumb|James Lind (1716 – 1794), a British Royal Navy surgeon who, in 1774, identified that a quality in fruit prevented the disease of scurvy in what was the first recorded controlled experiment.

Image:Pauling Vit C Book Cover.jpg|right|thumb|250px|Linus Pauling's popular and influential book How to Live Longer and Feel Better, first published in 1986, advocated very high doses of vitamin C.

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Serum and plasma vitamin C measurements do not correlate well with tissue levels while lymphocyte vitamin C levels provide the most accurate assessment of the true status of vitamin C stores and are not affected acutely by circadian rhythm or dietary changes.”

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I don't see any real reason for having a seperate article on ascorbic acid, because vitamin C and ascborbic acid are one and the same, as pointed out in this article. Also, a bunch of chemical properties are already included, so I suggest removing sentences aluding to a non-existent ascorbic acid article. I'll leave that to the original authors though. I don't know how to wrap text around images, so the image I added is centered with nothing around it: a waste of space. Feel free to fix this. David E. Volk 16:37, 31 July 2007 (CDT)

Proposition: creation of the "Discovery of vitamin C"/"Discovery and history of vitamin C" page

The lengthy explanations on the history of vitamin c are interesting but could be displayed in a separate article. CZ has the article : "Discovery of pennicilin". I consider that "Discovery of vitamin C" would be an interesting page in its own right and could be the place to explore those problems surrounding vit. C's discovery and patenting and related issues (e.g. how scurvy was gradually accepted, how nascent globalisation of trade enabled the provision of never before seen amounts of vit. C in the northern latitudes, etc.). The page could also be more accurately called : "Discovery and history of vitamin C". A redirect from "Discovery of vitamin C" to "Discovery and history of vitamin C" or "History of vitamin C" could be used. Pierre-Alain Gouanvic 16:57, 13 November 2007 (CST)

Go for it. Chris Day (talk) 03:17, 19 November 2007 (CST)

The basic structure

The whole debate about recommended intakes is one thing, and of course Linus Pauling (and his 1971 paper) is at the center of the debate. Keeping an historical perspective is logical and useful. The fact that bowel tolerance varies in function of disease pertains to another logic, and to another section. Finally, the therapeutic uses are another section. No info will be suppressed in the process of structuring this article. Pierre-Alain Gouanvic 03:29, 19 November 2007 (CST)

...the 1974 paper. The reference has been included. Pierre-Alain Gouanvic 18:04, 19 November 2007 (CST)

The "Politics of Vitamin C" section

Was this a part of the original WP article? Because saying there is a conspiracy against Vitamin C seems awfully absurd (unless it actually is the case). Is it actually something that goes on? Also some things about the "Hypothesis" section seem equally dubious. --Robert W King 16:45, 19 November 2007 (CST)

It comes from WP. I agree. I'll work on that and will try to be constructive. Thanks for the input; I'll send you a notice when I it is done. Pierre-Alain Gouanvic 17:32, 19 November 2007 (CST)

A description of a nutrient includes its distribution in tissues and organs. This section will necessarily cover (part of) the debate on vitamin C requirements. Putting this in a separate "controversial" section would be biased.Pierre-Alain Gouanvic 21:08, 19 November 2007 (CST)

The "Vitamin C hypothesis" section

Many things in this section reflect a lack of understanding of who said what, etc. They will be moved in their respective sections on biosynthesis. Pierre-Alain Gouanvic 00:05, 20 November 2007 (CST)

In the following, all parts that are in italics are false, as we can judge by reading the biosynthesis section:

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 man's ancestors once manufactured this substance in the body millions of years ago in quantities roughly estimated at 3,000–4,000 mg daily, but later lost the ability to do this through a chance of evolution. If true, this would mean that vitamin C was misnamed as a vitamin and is in fact a vital macronutrient like fat or carbohydrate. {Irwin Stone: "The Healing Factor"}

Dr. Hickey, of Manchester Metropolitan University, believes that man carries a mutated and ineffective form of the genetic machinery for manufacturing the fourth of the four enzymes used by all mammals to make ascorbic acid. Cosmic rays or a retrovirus could have caused this mutation, millions of years ago. {Hickey: "Ascorbate"} In humans the three surviving enzymes continue to produce the precursors to ascorbic acid but the process is incomplete and the body then disassembles them.

To be kept for future inclusion: the retrovirus hypothesis deserves its place; Irwin Stone's work, quoted in OMIM, too. Pierre-Alain Gouanvic 01:30, 20 November 2007 (CST)

Not useful in the intro, as it is in the chem box on its side

But the references will be useful:

also known by the chemical name of its principal form, L-ascorbic acid or simply ascorbic acid. Pierre-Alain Gouanvic 00:57, 21 November 2007 (CST)

Idem: The guidance provided by the United States of America and Canada for Dietary Reference Intake (DRI) recommends 90mg per day and no more than 2g per day (2000mg/day). Pierre-Alain Gouanvic 04:20, 21 November 2007 (CST)

Misplaced in the pharmacokinetics debate

Of course the following has to do with the debate:

Testing for ascorbate levels in the body Simple tests exist which measure levels of ascorbate ion in urine, serum or blood plasma. However, these tests do not accurately reflect actual tissue ascorbate levels. Reverse-phase high-performance liquid chromatography (HPLC) is used for determining vitamin C levels within lymphocytes and other tissue. It has been observed that while serum or blood plasma levels follow the circadian rhythm or short term dietary changes, levels within tissues are more stable and give a better determination of ascorbate availability within the organism. However, very few hospital laboratories are adequately equipped and trained to carry out such detailed analyses, and require samples to be analyzed in specialized laboratories.

... but this clearly deserves to be in the Distribution section. It will be important to provide a properly phrased link to the Distribution section. In +, the style doesn't have to be so colloquial. The example taken from diabetes is not especially useful: the article as it is now explains very clearly where, in the body, vitamin C is concentrated. Pierre-Alain Gouanvic 04:15, 21 November 2007 (CST)