Misplaced Pages

Revision as of 09:43, 18 March 2009

Medicine Start‑class Low‑importance

This article is within the scope of WikiProject Medicine, which recommends that medicine-related articles follow the Manual of Style for medicine-related articles and that biomedical information in any article use high-quality medical sources. Please visit the project page for details or ask questions at Misplaced Pages talk:WikiProject Medicine.MedicineWikipedia:WikiProject MedicineTemplate:WikiProject Medicinemedicine Start This article has been rated as Start-class on Misplaced Pages's content assessment scale. Low This article has been rated as Low-importance on the project's importance scale.

not a disambig page

The disambig template reads:

This disambiguation page lists articles associated with the same title. If an internal link led ''''you'''' here, you may wish to change the link to point directly to the intended article.

which this page clearly doesn't do.

I'm not sure why this is a disambig page. Vitamin C, Vitamin D, etc are all full articles. The B vitamins are chemically distinct, so it makes sense to have that page structured as it is. Are the "A vitamins" chemically distinct? I imagine that Retinol and other Retinods are similar. That is, is it even proper to say the "A vitamins"? Does it make sense that a page, like Antioxidant, would link to retinol rather than Vitamin A?

I propose that this page no longer be considered a disambig page. The disambig template should be removed, and the article on Vitamin A, in all forms, should be expanded (or simply allowed to expand).

Perhaps it could be marked a stub? Alternately, it should state that "When people refer to Vitamin A, they usually mean blank..." — baisically turning this short list into a short pargraph. Still, it shouldn't be a disambig page.

Any thoughts?

Disclaimer: IANAN, I am not a nutritionist (but I've seen one on TV). — gogobera (talk) 04:37, 21 December 2006 (UTC)

I was the one who turned this page into a disambig page. Basically I did it because I thought "retinol" was overly specific -- from a nutritional standpoint, you can get vitamin A from plant foods, but you can't get retinol from them, unless someone happens to have smeared them with liver :-). Anyway I kind of agree with you that this isn't the best solution as it stands -- most of the information at retinol really belongs at vitamin A, except for the purely chemical stuff. See talk:Retinol#Vitamin A redirects here; should it? and add your two cents. --Trovatore 04:47, 21 December 2006 (UTC)

I believe that most of the information on the retinol page belongs on this page. In fact the retinol page has more indepth information on vitamin A (especially from a biological perspective) than the vitamin A page. I think it is bizarre that most of the information on the retinol page is not about retinol. I do not have the technical skills to do this, but if someone worked on the organization I could help with the content. Jasonbholden (talk) 00:33, 11 April 2008 (UTC)

Cod liver oil

Why is there a link to this page titled "Vitamin A overdose"? --Connel MacKenzie - wikt 02:11, 1 January 2007 (UTC)

There is a 'See also' over at Cod liver oil, with a piped link called 'Vitamin A overdose' pointing to Retinol#Retinoid overdose (toxicity). Seems perfectly correct, so far as I can tell. The link was made before the articles on Retinol and Vitamin A were properly sorted out. It is logical to keep the information in the Retinol article because the overdose limitation doesn't seem to apply to beta-carotene. Though there is no separate upper limit given for the beta-carotene form of Vitamin A in our Hypervitaminosis A article. EdJohnston 19:15, 30 October 2007 (UTC)

I think that's wrong. It implies that beta carotene form leads to overdose. You could guess that that's not so from the equivalences section, but we ought to say it explicitly.WolfKeeper 14:52, 1 November 2007 (UTC)

I added a link to a new research paper, but I'm not sure if it is easy to link to that site...(links to a search)Filik (talk) —Preceding comment was added at 08:23, 11 December 2007 (UTC)

Pharmacological definition of Vitamin A

Perhaps this article could provide at least one link to a scientific paper that expounds the pharmacological definition. As a start, I found this short definition on the web:

"Pharmacology: The term vitamin A is applied to a number of substances with very similar structure and similar activity. The principal and most active substance is all-trans retinol (vitamin A alcohol). Vitamin A activity is assayed biologically and 1 IU equals 1 USP unit which is equal to 0.3 µg of all-trans retinol or 0.6 µg of beta-carotene. One retinol equivalent (RE) is the specific biologic activity of 1 µg of all-trans retinol (3.33 IU) or 6 µg (10 IU) of beta-carotene."

From . EdJohnston 17:55, 13 January 2007 (UTC)

Yet another link, this time for the medical uses of Vitamin A, at mayoclinic.com. . EdJohnston 02:00, 15 January 2007 (UTC)

Question about retinol and bone growth

Is retinol good for bone growth or only the pro-vitamin? I have heard that retinol can actually counteract Vitamin D and thus indirectly decrease bone density? More info about the different forms of Vitamin a and how they are absorbed/used by the human body would be appreciated, from anyone with the knowledge and interest to write it. 70.231.232.183 06:06, 28 August 2007 (UTC)

section needed: Health benefits

A section on Health benefits should be added, similar to B_vitamins#Health_benefits. Ajonlime 19:44, 14 September 2007 (UTC)

Please don't add it, this is just silly. We have information about hypo- and hypervitaminosis. Icek 03:11, 25 October 2007 (UTC)

HIgh vitamin-a foods

I removed apples and beef from the list. Neither seems to be high vitamin A foods; at the very least they were unreferenced.WolfKeeper 02:52, 2 November 2007 (UTC)

Thank you. I double checked this and my sources agree with yours. Antelan 03:59, 2 November 2007 (UTC)

Vitamin A is also in Avocado BTW

Capitalization?

I capitalized all instances of Vitamin A, instead of vitamin A. It seemed this was capitalized more than uncapitalized. If this is incorrect, please someone make this correction. Fredsmith2 (talk) 18:06, 10 December 2007 (UTC)

I agree that the capitalization should be consistent, but I think the lowercase version is more in line with WP conventions. There probably isn't an explicit MOS statement about vitamins (though it wouldn't shock me if there were; the people who work on the MOS have grabby fingers), but the general rule is that majuscule is used only when it pretty much has to be (proper nouns, quotations, the first word of an article title or section header). --Trovatore (talk) 18:12, 10 December 2007 (UTC)

kk nn —Preceding unsigned comment added by 219.79.160.239 (talk) 15:17, 20 February 2008 (UTC)

Preform vitamin A in foods

Vitamin A in animal foods is primarily in the form of retinyl esters (mostly retinyl palmitate), not retinol. Retinyl esters are hydrolyzed by lipases and retinyl ester hydrolase in the intestine to produce retinol for absorption. I will try to edit the fourth sentence of this article accordingly. 169.237.138.179 (talk) 17:42, 10 April 2008 (UTC) I finished my changes. If there are any errors or you want some references go ahead and make the appropriate changes. I do have texts that I could reference if you think that is necessary. Jasonbholden (talk) 17:57, 10 April 2008 (UTC)

Scope of the article

The article currently says that vitamin A is only retinoids. However, we have a separate article on retinoids, and additionally, in common usage vitamin A also applies to beta carotene. Further I googled 'vitamin A' and found this link which treats the two together. OTOH talks only about retinoid forms.

I'm thinking we should increase the scope of the article to cover carotenoids as well, perhaps including renaming it, or at least talk more about the range of opinions about what is, and isn't 'vitamin A'.

Comments?- (User) WolfKeeper (Talk) 22:43, 16 April 2008 (UTC)

A brief Google search suggests that the retinoids are the compounds that have vitamin A activity, and the carotenoids are considered precursors of vitamin A. I haven't yet found an article which says that beta-carotene *is* the vitamin. Even the NIH fact sheet that you have cited calls carotene a provitamin. Since vitamin A really has a biological definition (that we don't give) I think the lead of this article as well as retinoids could be improved. That's why the quantity of the vitamin is measured in International Units and not milligrams. Even a web source such as doesn't *quite* give the definition, since it talks about 'Vitamin A activity' but doesn't say what that consists of. This activity is probably the ability of a substance to relieve the symptoms of vitamin A deficiency in animals. More library research is needed. For instance, is it really true that carotene is unable to relieve the deficiency symptoms? EdJohnston (talk) 23:34, 16 April 2008 (UTC)

I agree with WolfKeeper -- one of the established usages of the term "vitamin A" includes beta carotene. This usage, for example, is commonly found on nutrition labels, and I would hazard a guess that it is the usage preferred by nutritionists, whereas the other usage is probably preferred by biochemists. We should strive to be clear, but not to favor one usage over the other. (Not too long ago, for example, vitamin A was a redirect to retinol, but somewhere there was a section on "foods containing vitamin A" that listed spinach, which has no retinol. Each of these choices was defensible on its own, but together they obviously failed to live up to the clarity required of WP.) --Trovatore (talk) 23:47, 16 April 2008 (UTC)

The NIH link offered above doesn't equate carotene and vitamin A. Rather it uses the terms 'preformed vitamin A' and 'provitamin A carotenoid.' I have yet to see reliable sources to show there is a group of specialists (nutritionists?) who consider these two the same thing. Though this article already has some very technical parts, it is missing important things like the discovery of the vitamin and the definition of vitamin A activity. It could also do a better job of explaining the relationship of carotenoids and vitamin A. Maybe it's time for a rewrite. EdJohnston (talk) 02:22, 17 April 2008 (UTC)

Specifically it says: Vitamin A that is found in colorful fruits and vegetables is called provitamin A carotenoid. They can be made into retinol in the body.. The thing is a vitamin is something that the body can use to perform a particular purpose, and both some carotenoids and retinoids can do the same things- they are both 'vitamin A' in that sense.- (User) WolfKeeper (Talk) 06:32, 17 April 2008 (UTC)

New edit regarding 'fat-soluble' appears to be contradictory

Though the fat-solublility is of interest, a recent edit that adds 'fat-soluble' to the lead appears to create a contradition. If Vitamin A is declared up front to be a fat-soluble vitamin, how can a sentence near the end claim that it has a water-soluble form? 'Vitamin A activity' is a biological activity and it seems to be measured by a bioassay. If Vitamin A is defined as whatever has that biological activity, then a wide variety of compounds (not all fat-soluble) ought to be considered to be Vitamin A. So it follows that 'fat-soluble' ought not to be announced as part of the vitamin's definition. It's fine for retinal to be described as fat-soluble, but retinal is not the only molecule that has Vitamin A activity. EdJohnston (talk) 02:24, 24 May 2008 (UTC)

Good point. My mistake. You're probably aware that vitamin A is considered to be fat-soluble by most of the public -- that's why I put it at the top, similar to the way that most of the B vitamins have "water-soluble" in their intro. Water-soluble vitamin A is a recent discovery. Incidentally, do you know much about retinyl palmitate? I think it may also be water-soluble; at the least, its Misplaced Pages article claims that it cannot be overdosed on. ImpIn | {talk - contribs} 02:36, 24 May 2008 (UTC)

You can overdose on retinyl palmitate. I highly doubt it is water soluble, as you are esterifying a relatively long chain fatty acid to retinol. Jasonbholden (talk) 20:06, 26 June 2008 (UTC)

Dermatology and isotretinoin

The dermatology section for Vitamin A talks more about isotretinoin, than it does about vitamin A.

It claims: "For the treatment of acne, the most effective drug is 13-cis retinoic acid (isotretinoin)." and then goes on to talk about isotretinoin for the rest of the paragraph. I feel this section is misplaced and possibly biased, it also does not have some of the most important information relating vitamin A, like this from the isotretinoin page: "The concurrent use of isotretinoin with tetracycline antibiotics or vitamin A supplementation is not recommended. Concurrent use of isotretinoin with tetracyclines significantly increases the risk of idiopathic intracranial hypertension. Concurrent intake of Vitamin A supplementation increases the risk of vitamin A toxicity." —Preceding unsigned comment added by 70.187.223.167 (talk) 02:38, 15 June 2008 (UTC)

Chart suggestion for vitamins and minerals.

Chart suggestion for vitamins and minerals.

Having been in business with a herbal department, there appears to be a need for a standardized presentation of vitamins and minerals to provide handy information to the general public.

Suggestion the following graph, if someone with this ability can present it as so.

Recommend a stardaized chart. Top lines, recommended daily allowance.

Then prioritized items that provide the element, together with amount of item in each serving and a percentage of the recommended daily allowance.

Why?

Well say vitamin C. One glass of orange juice. 100%

Vitamin D. One egg, 20. 3%

At the bottom of the chart important co ingredients required, and or negative factors to absorption.

--Caesar J.B. Squitti: Son of Maryann Rosso and Arthur Natale Squitti (talk) 09:43, 18 March 2009 (UTC)

• Start-Class medicine articles
• Low-importance medicine articles
• All WikiProject Medicine pages