Talk:Tocopherol/Archive 1

In relation to Alzheimer's Disease and the Oxidative stress article
Opinions of the effect of Vitamin E on the prevention of Alzheimer's Disease differ in this and the Oxidative stress article. -- Squater 27 June 2007

Reference # 19
is blank ???

deficiency
this page doesn't talk about what is perhaps the most important question about vitamin e: what are the symptoms or consecuencies of vitamin e deficiency?

This needs to be rewritten
Don't mean to be blunt, but including the work as it has been, although properly referenced, is considered plagiarism by many. The fact that much of the article is verbatim isn't stated except in the discussion page, and though the reference is provided, gives the reader the impression that this is a primary work.

A "further information" link should be provided in lieu of the text, although I don't see anything wrong with text that has been significantly rewritten/recomposed. --Lionelbrits 10:21, 15 Apr 2005 (UTC)

Accuracy of information...
I find myself concerned with the tone of this article in light of recent research (some of, if not all of which is credible). Additionally, some of the benefits listed have been discredited by recent studies. I believe simply dismissing some of the recently discovered risks as "media hype" is inaccurate, rash, and in some ways outright possibly dangerous. As an informational resource, wikipedians should be more aware of the need to supply as much accurate and useful information as possible in each article, and this one is no exception. Vitamins are not a topic that particularly excite me, but someone who has been working on this article should seriously consider revising it. Miros 17:53, 19 July 2005 (UTC)

Separate Vitamin E article needed
The other vitamins a to d all have separate articles on the Vitamin effects which social and biological as well as an article on the chemical properties of the molecule(s) which are the vitamin. Tocopherol should be split to separate the Vitamin and chemical elements into 2 articles. Lumos3 6 July 2005 11:09 (UTC)


 * See for a description of how vitamin e and the tocopherols are defined as separate entities by the IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN).


 * "The term vitamin E should be used as the generic descriptor for all tocol and tocotrienol derivatives exhibiting qualitatively the biological activity of alpha-tocopherol" ......"The term tocopherol(s) should be used as a generic descriptor for all mono, di, and trimethyltocols. Thus, this term is not synonymous with the term vitamin E".

Lumos3 12:49, 5 September 2005 (UTC)


 * I agree, I was looking for this article with great difficulty. 68.252.234.158 13:15, 11 May 2006 (UTC)

Deficiency
I came here trying to find out what Vitamin E deficiency does. Despite going on for ages about possible causes of vitamin E deficiency and speculating about vitamin E overdose, it doesn't tell me what the Vitamin actually does and what happens if you don't take it! mg e kelly 16:13, 27 May 2006 (UTC)

Health "risks" of vitamin E supplementation
I took the liberty of revising the last section of this article on the health risks of vitamin E supplementation, adding in more information about the Annals meta analysis published in 2005. The previous edit seemed to pay too much attention to criticism, whereas the accumulating evidence suggests consistently that there has been lack of benefit to vitamin E supplementation. Andrew73 03:53, 14 August 2006 (UTC)

SMILES
In case this article ever gets a chemical infobox, the SMILES notation for the molecule as drawn today is "CC(C)CCC[C@@H](C)CCC[C@@H](C)CCC[C@]1(C)CCc2c(O1)c(C)c(C)c(O)c2C". Catbar (Brian Rock) 02:17, 25 August 2006 (UTC)

Vitamin E supplements
I just carefully read this article, and it certainly appears that there is no value in Vitamin E supplementation. Is that the intended message? RXPhd 21:03, 26 October 2006 (UTC)
 * Apparently for conventionally oriented editors & physcians. For a more active coverage of the tocopherols and antioxidants story, pls see Orthomolecular medicine: Criticism and controversy as well as Talk, .---TheNautilus 23:12, 4 November 2006 (UTC)

Strange chemistry
The article states:
 * Synthetic vitamin E, usually marked as d,l-tocopherol or d,l tocopheryl acetate, with 50% d-alpha tocopherol moiety and 50% l-alpha-tocopherol moiety, as synthesized by an earlier process is now actually manufactured as all-racemic alpha tocopherol, with only about one alpha tocopherol molecule in 8 molecules as actual d-alpha tocpherol. 

I am not a chemist -- but -- if I read the article racemic, it states:


 * In chemistry, a racemate is a mixture of equal amounts of left- and right-handed enantiomers of a chiral molecule, such a mixture is called racemic.

which implies "all-racemic" means 50%d and 50%l, in seeming contradiction to this paragraph. It finally concludes with "with only about one alpha tocopherol molecule in 8 molecules as actual d-alpha tocpherol" implies a 12%d and 88%l, so this sounds just wrong. linas 04:55, 10 August 2006 (UTC)


 * Oh, never mind. Figured it out. There are 8 isomers so all-racemic really means 12% of each. That run-on sentance is confusingly worded.linas 05:03, 10 August 2006 (UTC)


 * Hopefully the details and wording are more clear now.--TheNautilus 23:27, 20 November 2006 (UTC)

Removed misinformation
I removed the assertion that "selenium, Coenzyme Q10, and ample vitamin C have been shown to be essential cofactors of natural tocopherols." This is nonsensical: a cofactor is a substance required for an ENZYME to function. You cannot have a cofactor for a vitamin. Vitamins themselves are cofactors or coenzymes. 154.20.96.9 00:08, 4 December 2006 (UTC)

Contradiction
In the "Vitamin E and cancer" section of this article, it states:

Recent studies also show that vitamin E acts as an effective free radical scavenger and can lower the incidence of lung cancer in smokers.[18]

When actually reading reference 18 - '''The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group.''' - it says:

Among the 876 new cases of lung cancer diagnosed during the trial, no reduction in incidence was observed among the men who received alpha-tocopherol (change in incidence as compared with those who did not, -2 percent; 95 percent confidence interval, -14 to 12 percent).

Therefore, the article here is wrong. There have in fact been other large randomized studies since of alpha-tocopherol, including the HOPE study and the Heart Protection Study, neither of which have shown effects on lung cancer.

82.10.96.227 21:18, 19 March 2007 (UTC)

Effects on skin
Is there any scientific evidence regarding the effect on skin? If not, this should probably be noted, lest we imply the cosmetic manufacturer's claims are true by omitting any reason why this might be doubted. Manufacturers are not a reliable source for medical effectiveness, but information about effectiveness is often what readers come to articles like this for. -- Beland 06:09, 16 April 2007 (UTC)

use as marker in f/MRI
If you can, please contribute to the vitamin E discussion on the MRI talk page. The questions are:
 * Is a specific form used? Why / Why not?
 * Wherefore the hyperintensity?
 * Are there other suitable, inexpensive markers? If so, what's the history behind the industry's using vitamin E? --Eitch 04:42, 3 May 2007 (UTC)

Vitamin E Myth (Cuts and Scars)
There is no evidence that Vitamin E speeds the healing of cuts or reduces scarring, this is an urban legend. In fact, research suggests that you could make the scar worse by using it, with 33 percent of those applying vitamin E developing contact dermatitis.
 * Added a source that backs this up, and mentioned some of it (not the contact dermatitis (that sounds worse than it really is, btw)) in the article. 171.71.37.103 21:42, 12 June 2007 (UTC)

Cannabis
This page says that tocopherols may reduce the neurological damage caused by THC, but the article on cannabis suggests that marijuana itself not only doesn't cause damage, but prevents neurotoxicity. One of these has to be rewritten to accommodate the other. 24.65.87.238 19:18, 31 October 2007 (UTC)Whatever my IP is

Alzheimer's section
Quoting one positive study is a bit misleading, since the evidence is very mixed. I've rewritten the section using reviews on the topic as sources. Tim Vickers (talk) 19:20, 2 May 2008 (UTC)

Requests for comment/TheNautilus
Editors of this article would be welcome to participate in this RfC. Tim Vickers (talk) 18:33, 31 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)

Section break
My recollection is the 1.36:1 ratio synthetic to natural tocopherol is as acetates. Rats, deficient is tocopherol, were fed diets containing either synthetic tocopheryl acetate or natural tocopheryl acetate and found the dietary level of natural tocopherol that prevented fetal resorption and it took 1.36 times as much if synthetic tocopheryl acetate was in the diet. Tocopherols was calculated from stoichiometry. Tocopherol, itself was likely unavailable but regardless, being an antioxidant is unstable and would add variability to the experiment. Tocopheryl acetates are highly stable.

Nevertheless the author’s opinion the factor should be 2:1 is supported by Ingold, Burton, Traber, Acuff et al using C12 C13 tagged tocopheryl acetates in human experiments.

I appreciate the author’s introduction of another and alternate nomenclature. . R meaning Rectus and S meaning Sinister and identical to d, dextro and l, levo in intent. The consequence is (of course) additional confusion for non chemists to sort out as to what is the chemical. An essential in chemical experiments is to the chemical and its purity and no different in biological experiments using chemicals. Pure ddd (or RRR, if you prefer) alpha tocopheryl acetate is a available. Synthetic alpha tocopheryl acetate is a mixture of eight chemicals, all similar none the less each different.

Thalidamid is a chemical that also exists in d and l forms. One of the forms dosed in pregnant women caused a tragedy.


 * Okanemachi, please sign your messages by leaving the four-tilde " ~ " marks. Thalidomide would have caused tragedy in any isomeric form, since the two tautomers intraconvert in water solution. Give either and you get the other. It's an urban myth (one which is probably untestable) than only one thalidomide tautomer is a teratogen. S  B Harris 22:16, 20 December 2009 (UTC)

What is dl???
The section titled "Alpha-tocopherol" should explain what "dl" means. The interested outsider probably will not have any idea what "dl" means. I came to this article looking for an explanation of "dl" and "ldl" and if it's there I can't decipher it. Olan7allen (talk) 06:12, 14 June 2008 (UTC)


 * Added. Tim Vickers (talk) 14:46, 15 June 2008 (UTC)

“d” means Dextro (right) and “l” means Levo (left). In early developments in organic chemistry it was found some molecules differed only in the way they rotated plane polarized light. Tartaric acid is an example where one form rotated polarized light to the right the other form to the left. Otherwise the two forms of tartaric acid are identical. Accordingly d tartaric acid and l tartaric acid are correct names for each form and dl tartaric acid for a mixture of the two in equal parts. The explanation lies in the arrangement of the four different groups attached to the carbon atom. It may be hard to visualize but the four groups can be arranged two ways in space. The phenomenon is generally described as handedness for the two arrangements for tartaric acid are in the same spatial relation as your left and right hands. Mirror images

The phenomenon of handedness is properly called stereoisomerism and d and l tartaric acid stereoisomers.

All molecules containing carbon and the carbon is surrounded by four different groups have stereoisomers and the site is called an asymmetric center.

Alpha tocopherol is a molecule with three asymmetric centers. Following the same nomenclature as with tartaric acid, the proper name for alpha tocopherol as found in nature is ddd alpha tocopherol, but usually just D-alpha tocopherol is used.

In chemical synthesis of tartaric acid an equal chance exists for each isomer to be created so dl tartaric acid is the result. The same consequence results with synthetic alpha tocopherol except with three asymmetric center eight possible stereoisomers are formed in equal parts as: ddd, ddl, dll, lll, lld, ldd, dld, ldl alpha tocopherol. Only one of those (ddd) is identical to natural alpha tocoperol, that is 1/8 of 12.5%.

To name synthetic alpha tocopherol dl alpha tocopherol is misleading as it seems to mean a mixture of two molecules analgous to dl tartaric acid, when in fact it’s a mixture of eight.

Semi synthetic alpha tocopherol, also called natural source and R-alpha tocopherol is simply a methylation of beta, delta and gamma tocopherol to match the fully methylated alpha tocopherol. The lesser active forms of tocopherol are by-products of vegetable oil processing and are made more potent by methylation. No stereo centers are created by methylation and the alpha tocopherol created is identical to that found in nature.

Significant differences exist between syn E and all nat E. In a pharmacokinetic study, both forms were absorbed by human volunteers at about the same rate, but the syn E was eliminated at twice the rate, meaning some, perhaps most, of those stereoisomers were simply rejected.

Researchers in Canada isolated tissues in rats fed both syn E and nat E and found in deep tissue a much higher concentration of nat E e.g. brain tissue.

These finding were presented to FDA ca 1988, since then papers seem more apt to carefully specify exactly which of the two Vitamin forms were used.

Prior experiments relating effects of Vitamin E should be reexamined for whether synthetic of all natural Vitamin E was used and especially where deep tissues should be affected. “No effects found” might be due to poor absorption of synthetic Vitamin E and/or failure e.g. to cross the blood brain barrier.

Finally relative potency of synthetic and all natural Vitamin E is based on biological tests related to pregnant rats fetal resorption, where the ratio of synthetic to natural to prevent resorption is (by memory?) 1.49. Exactly how does fetal resorption relate to humans seems an apt question. —Preceding unsigned comment added by Okanemachi (talk • contribs) 18:08, 18 December 2009 (UTC)

tail (i.e., RSR, RRS, RSS), appear to retain substantial RRR vitamin activity, because they are recognized by the alpha-tocopherol transport protein, and thus maintained in the plasma, where the other four stereoisomers (SRR, SRS, SSR, and SSS) are not. Thus, the synthetic all-rac-α-tocopherol probably has only about half the vitamin activity of RRR-alpha-tocopherol in humans, even though the ratio of activities of the 8 stereoisomer racemic mixture to the natural vitamin is 1 to 1.36 in the rat pregnancy model. S B Harris 19:12, 18 December 2009 (UTC)
 * The ratio is 1 to 1.36. But in humans the 4 isomers with the wrong steroconfiguration at the junction of ring and tail are not recognized by the alpha tocopherol transport protein, and probably have little vitamin activity for that reason. This also explains the failure of them to be retained (which is similar to non-alpha forms of vitamin E, actually, which also have shorter half-lives in the body for this reason-- it doesn't mean they are devoid of vitamin activity; it just means they have less). From the article: Natural alpha-tocopherol is the RRR-alpha (or ddd-alpha) form. The synthetic dl,dl,dl-alpha ("dl-alpha") form is not as active as the natural ddd-alpha ("d-alpha") tocopherol form. This is mainly due to reduced vitamin activity of the 4 possible stereoisomers which are represented by the l or S enantiomer at the first stereocenter (an S or l configuration between the chromanol ring and the tail, i.e., the SRR, SRS, SSR, and SSS stereoisomers).[3] The 3 unnatural "2R" stereoisomers with natural R configuration at this 2' stereocenter, but S at one of the other centers in the

1.36:1 refers to the tocopheryl acetate esters, 1.49:1 for tocopherol is calculated via stochiometryOkanemachi (talk) 16:03, 21 December 2009 (UTC)

No mentioning of "function" of tocopherol?
Or other vitamin Es. This paper and this might provide necessary information, and I will try to incorporate some of the information into the article if no one else gets there before I had the time to do so.

Keith Galveston (talk) 09:21, 29 June 2008 (UTC)

Please look to publications by Dr. Ron Sokol, University of Colorado. Children with Cholestasis do not absorb fats well and Vitamin E is a "fatty" molecule, meaning those children do not absorb sufficient dietary Vitamin E. Vitamin E insufficiency during development is crippling and eventually leads to prospect of premature death. It is believed, still I think, Vitamin E is essential in formation of the myelin sheath around nerves, whether it serves the formation or function is not known to me, but supplementation of afflicted children's diets with a water soluble form of Vitamin E is effective is reducing (eliminating?) symptoms. The water soluble Vitamin E form is based on ddd-alpha tocopherol i.e. all natural Vitamin E and popularly called TPGS for tocopherol(polyethylene glycol {1000}) succinate. . . a chemical modification the children do not need bile for absorption.

A synthetic "TPGS" is not available but brings to mind the doubt or wonder if such a chemical with 1/8 of the ddd form would access deep tissues where these children need it. Frankly I doubt it.

There are, perhaps, other diseases of Vitamin E deficiency more subtle and late happening, Alzheimer's and Parkinson's diseases come to mine. Any study involving Vitamin E in deep tissues (certainly the brain), but the researcher chose synthetic tocopherol should be done over with natural Vitamin E. The blood-brain barrier is tough to breach and (perhaps) little of the synthetic Vitamin E got through.

Speculation but: The functional group of tocopherol is C-OH and easily oxidized to C=O, the function of an antioxidant. Perhaps a function of tocopherol in vivo is C-OH <-> C=O and a switch OFF and ON. Would such a mechanism explain spastic muscles in Dr. Sokol's patients? Muscles do need a turn on and off switch. Nerve agents of military use interfere with that need. Does a Vitamin E insufficiency act similar? Dr. Sokol's patients seem to support that.Okanemachi (talk) 22:37, 21 December 2009 (UTC) —Preceding unsigned comment added by Okanemachi (talk • contribs) 22:34, 21 December 2009 (UTC)

Vitamin E is not simply tocopherol
from www.mercola.com/2003/sep/24/tocotrienols.htm

Vitamin E is comprised of two groups of molecules, tocopherols and tocotrienols, each with four forms (alpha-, beta-, gamma-, and delta-tocopherol, and alpha-, beta-, gamma- and delta-tocotrienol). Research is beginning to focus on specific tocopherols and tocotrienols, rather than just "vitamin E." Nonetheless, the vitamin E most often referred to and sold in most stores is a synthetic form called dl-alpha-tocopherol.

. . . I believe more accurately the most usual source sold in stores is dl alpha tocopheryl acetate, the acetate ester of synthetic tocopherol Okanemachi (talk) 22:11, 23 December 2009 (UTC)

Consider the argument listed at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16458936&query_hl=4&itool=pubmed_docsum

that d-tocopherol is not the only type of vitamin E.

Currently, searches for Vitamin E leap directly to a page for tocopherols, though the page acknowledge that tocotrienols are "Vitamin E."

Palm Oil as important source of Vit E

Natural palm oil contains alpha, beta, gamma, and delta-tocopherols and alpha, beta, gamma, and delta-tocotrienols (i.e. all of them!). No other source contains this much vitamin E.

Focusing on the vitamin E article
This article is much larger than the vitamin E article. This is likely to be confusing for some readers, and doesn't quite make sense since, as far as I know, dietary vitamin E intake actually leads to the consumption of the range of vitamin E chemicals. I suggest moving human dietary intake, deficiency, ect. sections to the vitamin E page and having this article focus on more intricate chemistry details of the four tocopherols. The vitamin E page should focus on alpha-tocopherol, mentioning in context the preliminary research into the other forms. II | (t - c) 18:21, 28 March 2009 (UTC)

Ingredient Labeling of Vitamin E. The INCI (International Nomenclature Cosmetic Ingredient Name) for vitamin E is Alpha Tocopherol. Therefore a label will not tell you if it is natural or synthetic vitamin E, or a mixture of tocopherols and tocotrienols. —Preceding unsigned comment added by 66.251.102.206 (talk) 00:48, 2 December 2009 (UTC)

How about merging it with Vitamin E into one article, like in most other language wikis ? --Lysytalk 05:33, 24 June 2010 (UTC)

Untitled
Correction in chemical Srtucture: delta-tocopherol should have R1 = CH3 rather than H. —Preceding unsigned comment added by 216.64.175.91 (talk) 19:56, 19 October 2007 (UTC)

The CAS number listed for B-tocopherol (490-23-3) is, in fact, the CAS number for B-Tocotrienol. The structure listed for delta-tocopherol as CAS (119-13-1) is consistent with CAS number and structure listed by large multinational supplier. — Preceding unsigned comment added by 129.94.191.27 (talk) 22:06, 13 March 2012 (UTC)

As a work of U.S. Federal Government agencies, the text in http://www.cc.nih.gov/ccc/supplements/vite.html appears to be a public domain resource which is available to use in this article.

I have taken in some of the text as a start. There is much more.

Cancer
The second sentence in this section of the article reads: "Antioxidants such as vitamin E help protect against the damaging effects of free radicals, which may contribute to the development of chronic diseases such as cancer."

But see para 3 of wiki article: http://en.wikipedia.org/wiki/Antioxidant "Antioxidants are widely used in dietary supplements and have been investigated for the prevention of diseases such as cancer, coronary heart disease and even altitude sickness. Although initial studies suggested that antioxidant supplements might promote health, later large clinical trials with a limited number of antioxidants detected no benefit and even suggested that excess supplementation with certain putative antioxidants may be harmful.[2][3][4]"

The furtherance of the simplistic antioxidant good/free radical bad myth by statements like this actually leads to people taking antioxidants which interfere with their cancer treatment: http://scienceblog.cancerresearchuk.org/2009/06/24/what-are-antioxidants-and-are-they-good-for-us-part-1/

I would suggest that it be removed.

I would also point out there are no citations to support the next sentence in this section: "Vitamin E may also block the formation of nitrosamines...", or the following one: "It also may protect against the development of cancers by enhancing immune function.", and that until citations are produced, these two sentences should also be removed.

Robocon1 (talk) 13:36, 9 April 2014 (UTC)

Butter
According to NutritionData.com, 100g of butter contains 2.3 mg, or 12% of the RDA of vitamin E, entirely in the form of alpha-tocopherol. Considering we're listing really minor sources like carrots (0.6mg?) why is butter absent from the list? I added it and it was immediately removed. — Preceding unsigned comment added by 79.14.250.194 (talk) 12:22, 10 October 2014 (UTC)

External links modified
Hello fellow Wikipedians,

I have just added archive links to 1 one external link on Tocopherol. Please take a moment to review my edit. If necessary, add after the link to keep me from modifying it. Alternatively, you can add to keep me off the page altogether. I made the following changes:
 * Added archive http://web.archive.org/web/20111108002304/http://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/ucm191033.htm to http://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/ucm191033.htm#ftnT

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).

Cheers.—cyberbot II  Talk to my owner :Online 16:58, 22 March 2016 (UTC)

200% w/w
What does this mean? Please provide an explanation within the text.

KC 18:09, 11 April 2016 (UTC) KC 18:09, 11 April 2016 (UTC) — Preceding unsigned comment added by Boydstra (talk • contribs)

Comment
User:Billyrayjoejimbob I have moved your comment here. This is where it belongs.

[NOTE] Either the original source cited here is incorrect, or it was incorrectly cited. R and S refer to the actual geometric configuration at a chiral center. In contrast, (d) and (l) refer to a purely observational phenomenon, the rotation of the plane of polarized light passed through a sample, and has no correlation whatsoever to the actual geometric configuration about any chiral centers. Whether a compound is (d) or (l) is a property of the whole molecule, and is not to be used to describe the individual chiral centers in a molecule containing multiple chiral centers. Compounds possessing a single chiral center that has the R geometric configuration are equally likely to be either (d) or (l), and similarly those with an S chiral center are equally likely to be either (d) or (l). There is no correlation between the actual geometric configuration at the chiral center and the observed rotation of plane polarized light. Tocopherol, having three chiral centers, has eight possible stereoisomers. There are four pairs of enantiomers, RRR/SSS, RRS/SSR, RSR/SRS, and RSS/SRR. For any given isomer, one other isomer is its enantiomeric mirror image, and the other six are all diastereomers. Furthermore, one enantiomer of each pair will be (d) and the other will be (l). This must be true for each pair of enantiomers. It is also true that there is no correlation between the observed rotation of the plane of polarized light and the actual geometric configuration of the groups at the chiral centers. Furthermore, it is not only absolutely incorrect to apply ddd or d,l d,l d,l to the three stereocenters of tocopherol, it is nonsensical gibberish. R and S are the ONLY designators that may be used to correctly identify the geometric configuration at a chiral center, and regardless of how many chiral centers are present or what their individual geometric configurations, each stereoisomer will be either (d) or (l) because that is a property of the whole molecule, not of the individual chiral centers. Multiple ds or ls applied to a single compound are meaningless and reflect a basic misunderstanding of the nomenclature of organic chemistry. The naturally occurring form of α-tocopherol (the RRR isomer) just so happens to be (d). However, three of the other diastereomers will ALSO be (d). This is a possible source of ambiguity and confusion, and hence has led to the use of the unambiguous designation, RRR.

-- Jytdog (talk) 10:19, 11 January 2017 (UTC)

Revising Age-related macular degeneration
The four refs of this section are all primary research = clinical trials, and only one (Taylor) was a trial of just vitamin E. Deleting all. Copying section and refs here so people can see what was deleted. Next step is to find better citations. David notMD (talk) 15:51, 18 March 2018 (UTC)

DELETED: Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the United States and the developed world among people 65 years and older. It has been shown that vitamin E alone does not attenuate the development or progression of AMD. However studies focusing on efficacy of Vitamin E combined with other antioxidants, such as zinc and vitamin C, indicate a protective effect against the onset and progression of AMD.
 * Vitamin E (400 IU/d) is part of the National Eye Institute (NEI) AREDS formula for AMD – arguably the best evidence of a formula containing "antioxidant vitamins A-C-E + zinc" for lowering high-risk of AMD – but vitamin E alone cannot be separated out as an individual protective factor. Given the NEI represents a WP:MEDSCI source, we might use it to reference that vitamin E is part of research to understand protective factors in AMD.  --Zefr (talk) 16:28, 18 March 2018 (UTC)
 * I agree, and have added text with two Cochrane reviews that covered vitamin E alone, and one AREDS citation that reported on the positive effect of the beta-carotene, vitamin C and vitamin E combination, with caveat that the effect can not be attributed to vitamin E alone. David notMD (talk) 16:37, 18 March 2018 (UTC)