Patients are asking THE PHARMACIST if vitamin E supplements are dangerous. Many people take vitamin E in hopes of preventing cardiovascular disease, dementia, etc. Vitamin E is a lipid soluble antioxidant best known for its ability to inhibit lipid peroxidation by scavenging reactive oxygen species and to preserve cell membranes. Now an analysis suggests that HIGH-dose vitamin E supplements might INCREASE the risk of fatal strokes.
Over 200 IU/day of vitamin E may PREVENT 21 ischemic strokes for every 10,000 patients treated for at least one year, but it may CAUSE 8 hemorrhagic strokes, which are more deadly (In meta-analysis, vitamin E increased the risk for haemorrhagic stroke by 22% and reduced the risk of ischaemic stroke by 10%).
Vitamin E inhibits platelet clotting especially with chronic, high doses. Tell patients they can continue to take a multivitamin, BUT to stop taking 200 IU/day or more of vitamin E if there's no medical need for it. Explain to patients the type of vitamin E doesn't matter, both natural and synthetic forms increase stroke risk at high doses.
REFERENCES
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Schürks M, Glynn RJ, Rist PM, Tzourio C, Kurth T. Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials. BMJ. 2010 Nov 4;341:c5702. Available at: https://pubmed.ncbi.nlm.nih.gov/21051774
Sesso HD, Buring JE, Christen WG, Kurth T, Belanger C, MacFadyen J, Bubes V, Manson JE, Glynn RJ, Gaziano JM. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. JAMA. 2008 Nov 12;300(18):2123-33. Available at: https://pubmed.ncbi.nlm.nih.gov/18997197
Lee IM, Cook NR, Gaziano JM, Gordon D, Ridker PM, Manson JE, Hennekens CH, Buring JE. Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women's Health Study: a randomized controlled trial. JAMA. 2005 Jul 6;294(1):56-65. Available at: https://pubmed.ncbi.nlm.nih.gov/15998891