Editing Tocopherol (section)

==Side effects==
The U.S. Food and Nutrition Board set a [[Tolerable upper intake levels|Tolerable upper intake level (UL)]] at 1,000&nbsp;mg (1,500 IU) per day derived from animal models that demonstrated bleeding at high doses.<ref name="DRItext">{{cite book | last1 = Institute of Medicine | title = Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids | chapter = Vitamin E | publisher = The National Academies Press | year = 2000 | location = Washington, DC | pages = 186–283 | doi = 10.17226/9810 | pmid = 25077263 | isbn = 978-0-309-06935-9 | chapter-url = https://www.nap.edu/read/9810/chapter/8 | url-status = live | archive-url = https://web.archive.org/web/20180226152013/https://www.nap.edu/read/9810/chapter/8 | archive-date = 2018-02-26 | author1-link = Institute of Medicine }}</ref> The [[European Food Safety Authority]] reviewed the same safety question and set a UL at 300&nbsp;mg/day.<ref name=EFSA-UL/> A meta-analysis of long-term clinical trials reported a non-significant 2% increase in all-cause mortality when α-tocopherol was the only supplement used.<ref name=Bjelakovic2014>{{cite journal | vauthors = Bjelakovic G, Nikolova D, Gluud C | title = Meta-regression analyses, meta-analyses, and trial sequential analyses of the effects of supplementation with beta-carotene, vitamin A, and vitamin E singly or in different combinations on all-cause mortality: do we have evidence for lack of harm? | journal = PLOS ONE | volume = 8 | issue = 9 | pages = e74558 | date = 2013 | pmid = 24040282 | pmc = 3765487 | doi = 10.1371/journal.pone.0074558 | bibcode = 2013PLoSO...874558B | doi-access = free }}</ref> Another meta-analysis reported a non-significant 1% increase in all-cause mortality when α-tocopherol was the only supplement. Subset analysis reported no difference between natural (plant extracted) or synthetic α-tocopherol, or whether the amount used was less than or more than 400 IU/day.<ref>{{cite journal | vauthors = Curtis AJ, Bullen M, Piccenna L, McNeil JJ | title = Vitamin E supplementation and mortality in healthy people: a meta-analysis of randomised controlled trials | journal = Cardiovascular Drugs and Therapy | volume = 28 | issue = 6 | pages = 563–73 | date = December 2014 | pmid = 25398301 | doi = 10.1007/s10557-014-6560-7 | s2cid = 23820017 }}</ref> There are reports of vitamin E-induced allergic contact dermatitis from use of vitamin-E derivatives such as tocopheryl linoleate and tocopherol acetate in skin care products. Incidence is low despite widespread use.<ref name=Kosari2010>{{cite journal | vauthors = Kosari P, Alikhan A, Sockolov M, Feldman SR | title = Vitamin E and allergic contact dermatitis | journal = Dermatitis | volume = 21 | issue = 3 | pages = 148–53 | date = 2010 | pmid = 20487657 | doi =  10.2310/6620.2010.09083| s2cid = 38212099 }}</ref>

===Drug interactions===
The amounts of α-tocopherol, other tocopherols and tocotrienols that are components of dietary vitamin E, when consumed from foods, do not appear to cause any interactions with drugs. Consumption of α-tocopherol as a dietary supplement in amounts in excess of 300&nbsp;mg/day may lead to interactions with [[aspirin]], [[warfarin]], [[tamoxifen]], and [[cyclosporine A]] in ways that alter function. For aspirin and warfarin, high amounts of vitamin E may potentiate anti-blood clotting action.<ref name=GOVe/><ref name=Podszun2014>{{cite journal | vauthors = Podszun M, Frank J | title = Vitamin E-drug interactions: molecular basis and clinical relevance | journal = Nutrition Research Reviews | volume = 27 | issue = 2 | pages = 215–31 | date = December 2014 | pmid = 25225959 | doi = 10.1017/S0954422414000146 | doi-access = free }}</ref> One small trial demonstrated that vitamin E at 400&nbsp;mg/day reduced blood concentration of the anti-breast cancer drug tamoxifen. In multiple clinical trials, vitamin E lowered blood concentration of the immuno-suppressant drug, cyclosporine A.<ref name=Podszun2014/> The U.S. National Institutes of Health, Office of Dietary Supplements, raises a concern that co-administration of vitamin E could counter the mechanisms of anti-cancer radiation therapy and some types of chemotherapy, and so advises against its use in these patient populations. The references it cited reported instances of reduced treatment adverse effects, but also poorer cancer survival, raising the possibility of tumor protection from the oxidative damage intended by the treatments.<ref name=GOVe/>