vitamin E (generic name)
a vitamin - treats Atherosclerosis, Seizure disorder, Steatohepatitis, Respiratory infection prevention, Osteoarthritis, Parkinson's disease, P...
Table of Contents
Top Learning Centers(Recursos en Español)
Interactions with Drugs
The amount of bleeding risk associated with vitamin E remains an area of controversy, and caution is warranted in patients with a history of bleeding disorders or taking blood-thinning drugs such as aspirin, anticoagulants such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Concern has been raised that antioxidants may interfere with some chemotherapy agents (such as alkylating agents, anthracyclines, or platinums), which themselves can depend on oxidative damage to tumor cells for their anti-cancer effects. Studies on the effects of antioxidants on cancer therapies have yielded mixed results, with some reporting interference, others noting benefits, and most suggesting no significant interaction. However, until additional scientific evidence is available, high-dose antioxidants should be avoided during chemotherapy administration, unless otherwise decided in discussion with the treating oncologist.
Cholestyramine (Questran ®), colestipol (Colestid®), orlistat (Xenical®), isoniazid (INH, Lanizid®, Nydrazid®), olestra (Olean® fat substitute), and sucralfate (Carafate®) can reduce dietary vitamin E absorption and blood levels of vitamin E. Gemfibrozil (Lopid®) may decrease serum levels of both alpha- and gamma-tocopherol, although clinical significance is not clear. Anticonvulsant drugs such as phenobarbital, phenytoin, or carbamazepine may decrease blood levels of vitamin E.
Vitamin E use with cyclosporine appears to increase the area under the blood concentration-time curve of cyclosporine. A water-soluble form of vitamin E, tocopheryl succinate polyethylene glycol, may improve the absorption of cyclosporine (observed after liver transplantation).
Vitamin E may have additive effects with cholesterol-lowering medications.
Interactions with Herbs and Dietary Supplements
High doses of oral or injected vitamin E may increase the risk of bleeding including hemorrhagic stroke (bleeding into the brain), and caution is warranted in patients with a history of bleeding disorders or taking herbs or supplements that may also increase the risk of bleeding. For example, multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic or saw palmetto.
Vitamin E may have additive effects with cholesterol-lowering herbs and supplements.
Mineral oil may reduce dietary vitamin E absorption. Blood levels of vitamin E may be decreased with zinc deficiency. Increased intake of omega-6 fatty acids may increase vitamin E requirements, particularly at high doses.
Vitamin E is involved in the absorption, storage, and utilization of vitamin A in the body and contributes to avoiding toxicity with vitamin A intake. Large doses of vitamin E may deplete vitamin A stores.
Aloe is reported to slow the rate of vitamin E absorption, allowing sustained release of vitamin E into the bloodstream.
Vitamin E has been proposed to improve the bioavailability of iron.
This information is based on a systematic review of scientific literature, edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Wendy Chao, PhD (Natural Standard Research Collaboration); Dawn Costa, BA, BS (Natural Standard Research Collaboration); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts College of Pharmacy); Christine Ulbricht, PharmD (University of Massachusetts); Wendy Weissner, BA (Natural Standard Research Collaboration).