Vitamin E Safety & Side Effects
Our assessment
Based on FDA data, vitamin E supplements carry a significant safety signal that requires attention. The most important finding is that high doses of vitamin E — above the upper limit of 1,000 mg/day for adults — can increase the risk of bleeding by reducing the blood's ability to form clots after a cut or injury, and may increase the risk of serious bleeding in the brain, known as hemorrhagic stroke FDA FAERS ↗ NIH ODS ↗. This risk is dose-dependent and is not associated with vitamin E naturally present in food.
Safety profile
FDA adverse event data for vitamin E supplements includes reports of bleeding complications. Specific side effects from the FDA data include reports of hemorrhage and increased INR (a measure of blood clotting time). The data indicates that these bleeding events are the primary safety concern, with the risk of hemorrhagic stroke being the most serious potential outcome FDA FAERS ↗. The upper limit for adults is set at 1,000 mg/day for supplements, which equals 1,500 IU/day for natural vitamin E NIH ODS ↗.
Who should be cautious
Specific populations should exercise caution with vitamin E supplements. People taking anticoagulant or antiplatelet medicines, such as warfarin (Coumadin), are at increased risk of bleeding because vitamin E can interact with these drugs to further reduce blood clotting NIH ODS ↗. In one study, vitamin E plus other antioxidants showed an interaction that increased bleeding risk NIH DSLD ↗. Anyone scheduled for surgery should also be cautious and discuss vitamin E use with their healthcare provider due to the bleeding risk. The dose threshold for concern is above 1,000 mg/day for adults NIH ODS ↗.
Our recommendation
We recommend obtaining vitamin E primarily from food sources, as vitamin E naturally present in food is not harmful and does not need to be limited NIH ODS ↗. If you choose a supplement, do not exceed the upper limit of 1,000 mg/day (1,500 IU/day for natural vitamin E) NIH ODS ↗. If you take blood-thinning medications like warfarin, consult your doctor before using vitamin E supplements due to the risk of increased bleeding NIH ODS ↗ FDA FAERS ↗. Monitor for signs of easy bruising or prolonged bleeding, and report these to a healthcare provider immediately.
AI-assisted analysis. Data sourced from NIH ODS and FDA.
Safety Overview
Vitamin E that is naturally present in food and beverages is not harmful and does not need to be limited. In supplement form, however, high doses of vitamin E might increase the risk of bleeding (by reducing the blood's ability to form clots after a cut or injury) and of serious bleeding in the brain (known as hemorrhagic stroke ). Because of this risk, the upper limit for adults is 1,000 mg/day for supplements of either natural or synthetic vitamin E. This is equal to 1,500 IU/day for natural vitamin E supplements and 1,100 IU/day for synthetic vitamin E supplements. The upper limits for children are lower than those for adults. Some research suggests that taking vitamin E supplements even below these upper limits might cause harm. In one study, for example, men who took 400 IU (180 mg) of synthetic vitamin E each day for several years had an increased risk of prostate cancer.
Drug Interactions
Vitamin E dietary supplements can interact or interfere with certain medicines that you take. Here are some examples: Vitamin E can increase the risk of bleeding in people taking anticoagulant or antiplatelet medicines, such as warfarin (Coumadin). In one study, vitamin E plus other antioxidants (such as vitamin C , selenium , and beta-carotene ) reduced the heart-protective effects of two drugs taken in combination (a statin and niacin ) to affect blood cholesterol levels. Taking antioxidant supplements while undergoing chemotherapy or radiation therapy for cancer could alter the effectiveness of these treatments. Tell your doctor, pharmacist , and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines, or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.