Vitamin E: the antioxidant that failed its trials and then caused harm

Vitamin E was the antioxidant that everything was expected of, and it is now one of the best documented cases of a supplement that did not deliver and turned out to carry its own risk. The nutrient itself is not the problem. The dose in a bottle is.

What it does in the body

• Vitamin E is a fat-soluble antioxidant that stops the production of reactive oxygen species formed when fat is oxidised. — general adults Evidence E source

How much you need

• The RDA for vitamin E is 15 mg a day from age 14 and over. — general adults Evidence E source
• The Tolerable Upper Intake Level for vitamin E is 1,000 mg a day for adults aged 19 and over. — general adults Evidence E source
• Sunflower oil is the richest everyday source of vitamin E, ahead of corn, rapeseed, olive and soybean oil - but in a real diet most of it arrives through bread, spreads and dressings rather than through anything anyone thinks of as a vitamin E food. — adults in the Nordic and Baltic countries; Finnish adults specifically for the source breakdown Evidence E source
• Whether Northern Europeans get enough vitamin E depends entirely on whose recommendation you open: the same 8.8 to 13.2 mg a day falls short of the American 15 mg and meets the Nordic 10 and 8 mg. — adult populations of the Nordic and Baltic countries Evidence E source
• The 15 mg a day recommended for vitamin E was not measured in anyone: it was extrapolated from an older figure, itself derived from depletion studies in men using a test-tube measure of how easily red cells burst. — the depletion-repletion studies behind the value were conducted in men Evidence E source
• The number printed as "vitamin E" in a food table may mean alpha-tocopherol alone or every form of the vitamin together, and EFSA says outright that the databases do not agree which. — European food composition databases and packaged food labelling Evidence E source

How well your body absorbs it

• Synthetic vitamin E is worth half of what the natural form is worth, milligram for milligram - and the typical single-vitamin capsule holds at least four times the daily recommendation either way. — general population buying vitamin E supplements Evidence E source
• There is no single way to turn international units of vitamin E into milligrams: the same 1 mg is 1.49 IU if the vitamin is natural and 2.22 IU if it is synthetic. — general population reading labels, US Evidence E source
• How much vitamin E you get out of a meal ranges from a tenth to four fifths of what was on the plate, and the single thing that moves it most is how much fat was eaten with it. — загальна доросла популяція Evidence E source
• Adding two cooked eggs to a raw vegetable salad multiplied the vitamin E absorbed from that salad about eightfold - and one egg was not enough to show an effect. — healthy young men, mean age 24 years, mean BMI 24 Evidence B source
• The fat that helps you absorb vitamin E turns out to be the fat in your next meal, not the one you swallowed it with - and in women with obesity and fatty liver that rescue works a third less well. — healthy women, plus a separate cohort of women with obesity and metabolic dysfunction-associated steatotic liver disease and normal-weight controls Evidence B source
• Of the eight forms of vitamin E, the liver keeps only one. Everything else - gamma-tocopherol, the tocotrienols, the "mixed tocopherols" on the label - is broken down and sent out in the bile. — не застосовується: фізіологія Evidence E source

What too little does

• Vitamin E deficiency damages nerves and muscles, upsets balance, harms the retina and weakens the immune response. — people with vitamin E deficiency Evidence E source
• A blood test for vitamin E means little on its own, because the number rises with blood fats - so an older person with high cholesterol can look vitamin E replete without being so. — general population; specifically people with high or abnormally low plasma lipids Evidence E source

Who is most likely to fall short

• People with Crohn's disease, cystic fibrosis or blocked bile flow cannot absorb fat properly, and vitamin E needs fat to be absorbed. — people with fat-malabsorption disorders Evidence E source
• Breast milk carries vitamin E, and how much depends on the mother: obesity, smoking and preterm birth all go with less of it - while what a supplement beyond the ordinary dose would do to the baby has never been looked at. — lactating women and breastfed infants Evidence E source

What the evidence does and does not show

• The NIH states the evidence so far is insufficient to support taking vitamin E to prevent cancer. — general adult population Evidence E source
• In the SELECT trial, men who had taken vitamin E had 17 per cent more prostate cancer than men on placebo after further follow-up. — men in the SELECT randomised trial Evidence B source
• In a randomised trial in 124 people with fatty liver disease confirmed by biopsy, 300 mg of vitamin E a day improved the liver tissue in 29 per cent of them against 14 per cent on placebo. — non-diabetic adults in China with biopsy-proven metabolic dysfunction-associated steatohepatitis Evidence B source
• A review of vitamin supplement trials for dementia found the evidence for vitamin E too thin to recommend it. — older adults with normal cognition or mild cognitive impairment Evidence A source
• Vitamin E on its own does not prevent stroke. Taken with other antioxidants it slightly reduces the clot kind and slightly increases the bleeding kind, so the two cancel out. — adults in 16 randomised controlled trials of vitamin E alone or combined with other antioxidants Evidence A source
• Fatty liver disease is the one condition where vitamin E moves the tissue itself: pooling six meta-analyses, it lowered liver enzymes and both fibrosis and steatosis scores. — patients with non-alcoholic fatty liver disease Evidence A source
• In people who have both type 2 diabetes and biopsy-confirmed steatohepatitis, 800 IU of vitamin E a day for 18 months missed its main target, and only the combination with pioglitazone hit it. — patients with type 2 diabetes and biopsy-confirmed non-alcoholic steatohepatitis Evidence B source
• For Alzheimer's disease the pooled estimate sits on no effect and the confidence interval is wide enough to hold both a halving of risk and a third more of it. — adults in five cohort studies and three randomised controlled trials, for risk of Alzheimer's disease and for its progression Evidence C source
• Vitamin E really does do the thing it was supposed to do - it makes LDL harder to oxidise - which is exactly why the trials that found no benefit for the heart are worth taking seriously. — participants in clinical trials of vitamin E supplementation reporting LDL oxidation outcomes Evidence A source

What too much does

• High doses of alpha-tocopherol supplements can cause haemorrhage and interrupt blood coagulation in animals. — general adults Evidence E source
• Pooling 19 trials in 136,000 people, doses of 400 IU a day or more went with 39 extra deaths per 10,000 people, and the dose-response curve turned upward above 150 IU a day. — participants in 19 clinical trials, 9 of vitamin E alone and 10 of vitamin E in combination, doses 16.5 to 2,000 IU a day, median 400 Evidence A source
• Nothing bad has ever been described from the vitamin E in food. The problems start at 300 mg a day from a bottle, and they are problems with other medicines. — adults; specifically those taking high-dose alpha-tocopherol supplements alongside medication Evidence E source
• The 1,000 mg ceiling for vitamin E looks precise and is not: it rests on small groups of people who took high doses for a few weeks or months, and nobody has tested what years of it do. — adults, United States Evidence E source
• Two large trials found more brain bleeds in people taking vitamin E - one at 50 mg a day in smokers, one at 400 IU every other day in doctors who were mostly also taking aspirin. — Finnish male smokers in one trial; US male physicians, most of them also taking aspirin, in the other Evidence E source
• Every reported harm from vitamin E comes from supplements. From food, none has ever been found. — general population Evidence E source
• Europe and America disagree about how much vitamin E is too much by a factor of more than three: EFSA re-examined the question in 2024 and kept its ceiling at 300 mg a day, against the American 1,000. — adults in the European Union, plus pregnancy, lactation, children and adolescents Evidence E source
• Nobody has ever tested how much vitamin E is too much for a child. The children's limit was calculated from the adult one by body weight, and in 2024 EFSA confirmed there is still nothing to replace that arithmetic with. — children and adolescents aged 1-17 years Evidence E source

Medicines it interacts with

• Large doses of vitamin E taken with warfarin or antiplatelet drugs can raise the risk of bleeding. — people on anticoagulant or antiplatelet medication Evidence E source

What to do with this

Sunflower seeds, almonds, hazelnuts, peanut butter and vegetable oils cover vitamin E, and 15 mg a day is a modest target. A handful of sunflower seeds gets most of the way there.

The supplement is where the trouble is. High doses interfere with blood clotting, which makes them a real risk for anyone on warfarin, aspirin or another antiplatelet drug. On the claims that sold vitamin E in the first place, the evidence for preventing cancer is insufficient, and in one large trial men who had taken it ended up with 17 per cent more prostate cancer than men on placebo.

Deficiency is rare and almost always belongs to someone with a condition that blocks fat absorption, such as Crohn's disease or cystic fibrosis, rather than to a poor diet.

The one place vitamin E is used as a medicine is fatty liver disease. A randomised trial in 124 people with the diagnosis confirmed by biopsy found 300 mg a day improved the liver tissue in 29 per cent of them against 14 per cent on placebo. That is a prescription decision, made after a biopsy, and it does not transfer to anyone who has simply been told their liver looks bright on an ultrasound. On dementia, a review of the supplement trials found the evidence for vitamin E too thin to recommend it.

If a vitamin E capsule is already on your shelf, look at its dose rather than at the ceiling on the label. Pooled across 19 trials in 135,967 people, the ones using 400 IU a day or more came out with 39 extra deaths per 10,000, and the curve begins to rise above about 150 IU. Four hundred IU is an ordinary capsule. Those trials were mostly run in people who already had a chronic illness, so the figure does not carry across cleanly, and it is still the wrong direction for something bought to keep you well.

Two continents, one vitamin, and a threefold gap

Unsettled. The upper limit for vitamin E is 1,000 mg a day in the United States and 300 mg a day in the European Union. EFSA looked at the question again in 2024 and kept its number, derived from bleeding-time studies at 800 IU of the synthetic form, about 728 mg of free alpha-tocopherol. It applies that limit to every form of the vitamin and to pregnancy and breastfeeding. The American figure is built on limited data: small groups taking up to 3,200 mg a day for a few weeks or months, and nothing at all about what taking it for years does. Two authorities, the same evidence base, a 3.3-fold difference in what they call safe. A 400 IU capsule, which is about 180 mg of the synthetic form, sits comfortably under one of those ceilings and within sight of the other.

Not for everyone. Nobody has ever tested how much vitamin E is too much for a child. The limits for ages 1 to 17 were calculated from the adult figure by body weight, and in 2024 EFSA confirmed there is still no evidence to replace that arithmetic with. If a child is taking vitamin E, the number on the bottle is extrapolation rather than measurement, and that is a reason for a doctor to be involved.

What the label is not telling you

Vitamin E is the nutrient where the units fight back. Synthetic all-rac-alpha-tocopherol, labelled DL or dl, contains all eight stereoisomers and your body keeps only four of them, which makes it worth about half of the natural RRR form, labelled D or d, milligram for milligram. Most vitamin-E-only capsules hold at least four times the daily recommendation either way.

There is also no single conversion between international units and milligrams. One milligram of alpha-tocopherol is 1.49 IU if the vitamin is natural and 2.22 IU if it is synthetic. Going the other way, 1 IU is 0.67 mg natural and 0.45 mg synthetic. Any conversion quoted without saying which form it meant is wrong by up to a third.

Even the food tables wobble. EFSA says outright that composition databases are not harmonised and are sometimes ambiguous about whether a figure means alpha-tocopherol alone or every form of the vitamin added together, and that this probably overstates the alpha-tocopherol actually present. Of the eight forms, the liver keeps one. A transfer protein picks out alpha-tocopherol and sends it onward, and the gamma-tocopherol, the tocotrienols and the mixed tocopherols advertised on the front of a bottle are broken down and sent out in bile.

Fat is the whole absorption story, and the timing is odd

How much vitamin E you get out of a meal runs anywhere from 10 to 79 per cent of what was on the plate. What moves that number most is how much fat came with it. Fat frees the vitamin from the food, brings out bile and forms the droplets that carry it across.

Established. The size of that effect is easy to underrate. A raw vegetable salad with a little oil was eaten with no egg, with 75 g of cooked egg, or with 150 g. The vitamin E absorbed over ten hours went from 117 to 311 to 981 in the same units. The two eggs multiplied it about eightfold. One egg did not differ from no egg at all, which says the amount of fat has to clear a threshold before anything happens.

Unsettled. The timing is stranger than the rule suggests. In one study the fat that mattered was not the fat swallowed with the vitamin. A 40 per cent fat breakfast and a 0 per cent fat breakfast gave the same blood levels at four hours. The difference appeared after the next meal, where the people who had eaten no fat at breakfast got 55 per cent more out of the second meal and ended up ahead. In women with obesity and fatty liver, that rescue worked about a third less well. So the common instruction to take vitamin E with a fatty meal is roughly right and the mechanism underneath it is not settled.

Where it actually comes from, and how much is enough

Sunflower oil is the richest everyday source, ahead of corn and rapeseed, then olive and soybean. In a real diet most of it does not arrive as oil anyone notices. About half of Finnish adults' alpha-tocopherol came from cereals, bakery products, fat spreads, oils and dressings.

Unsettled. Whether Northern Europeans get enough depends entirely on whose recommendation you open. Intake runs 8.8 to 13.2 mg a day in the Nordic countries and 7.8 to 13.9 in the Baltic ones. Those figures fall short of the American 15 mg and meet the Nordic 10 mg for men and 8 for women. Same dinners, two verdicts. It is worth knowing where the 15 mg came from: it was not measured in anybody. It was extrapolated from an older figure, itself derived from depletion studies in men using a test-tube measure of how easily red blood cells burst in hydrogen peroxide. That is a reasonable marker and it is a long way from a health outcome.

Established. One thing about vitamin E is settled and it is the most instructive result on this page. Vitamin E really does do the thing it was supposed to do. Pooled trials show oxidised LDL falling and LDL taking longer to oxidise. The mechanism works, it is measurable, and the outcome trials still found no benefit for the heart. A supplement can change the marker it was designed around and change nothing that happens to a person, and vitamin E is the clearest example anyone has.

Unsettled. A blood test here means less than it looks. Plasma alpha-tocopherol rises with blood fats, and blood fats rise with age, so an older person with high cholesterol can look replete without being so. The number needs correcting for lipids before it says anything, and most reports do not.

Established. Nothing bad has ever been described from the vitamin E in food. Every documented harm, the bleeding, the interference with platelets, the haemorrhagic strokes, comes from high-dose supplements. Two large trials are worth naming because their doses were not extreme. Finnish male smokers on 50 mg a day for an average of six years had more brain bleeds, and so did American male doctors taking 400 IU every other day for eight years, most of whom were also taking aspirin.

Where to get it from food

The bottom line

Fifteen milligrams a day covers an adult, and nuts, seeds and vegetable oils supply it without effort. Deficiency is rare and almost always belongs to someone who cannot absorb fat. The upper limit is 1,000 mg, and high doses of alpha-tocopherol interfere with blood clotting, which matters a great deal for anyone on warfarin or antiplatelet drugs. On cancer prevention the evidence is insufficient, and in one large trial men who had taken vitamin E had 17 per cent more prostate cancer than men on placebo. There is one modern exception. In people with fatty liver disease confirmed by biopsy, a randomised trial of 300 mg a day improved the liver tissue in 29 per cent of them against 14 per cent on placebo. That is a decision for a hepatologist rather than a reason to buy a bottle. Five results have landed since this page was written and they tighten the same conclusion. Pooled by dose, 19 trials in 135,967 people showed 39 extra deaths per 10,000 in the trials using 400 IU a day or more, with the curve turning upward above roughly 150 IU, well below the 1,000 mg on the label. On stroke, vitamin E alone did nothing, and with other antioxidants it cut the clot kind by 9 per cent while raising the bleeding kind by 22 per cent, which the reviewers read as cancelling out. For Alzheimer's disease the pooled estimate sits on no effect, with an interval wide enough to hold both a halving of risk and a third more of it, so nobody can say either way. The liver exception holds and gets harder to act on. Six meta-analyses pooled together show vitamin E lowering liver enzymes and both the scarring and fat scores, with the scarring moving only above 600 IU a day, which is inside the range the mortality analysis flagged. And in 105 people who had type 2 diabetes alongside the liver disease, 800 IU a day for 18 months missed the trial's main target, which only the combination with a diabetes drug reached. The 1,000 mg ceiling quoted above is the American one, and Europe does not agree. EFSA re-examined the question in 2024 and kept its own limit at 300 mg a day, which is more than three times lower, and applied it to pregnancy and breastfeeding as well. Both numbers rest on bleeding rather than on organ damage, and the American figure comes from small groups who took high doses for weeks or months, so nobody has tested what years of it do. Two other things belong here. Synthetic vitamin E is worth about half of the natural form milligram for milligram, and no harm has ever been described from the vitamin E in food.

Sources

1. vite-01 · Position of an expert body · expert body statement
   Vitamin E is a fat-soluble antioxidant that stops the production of ROS formed when fat undergoes oxidation.
   NIH Office of Dietary Supplements, VitaminE - Health Professional Fact Sheet · checked 2026-09-16 · extracted
2. vite-02 · Position of an expert body · expert body statement
   14+ years: 15 mg (value from the source's table, not a sentence)
   NIH Office of Dietary Supplements, VitaminE - Health Professional Fact Sheet · checked 2026-09-16 · extracted
3. vite-03 · Position of an expert body · expert body statement
   19+ years: 1,000 mg (value from the source's table, not a sentence)
   NIH Office of Dietary Supplements, VitaminE - Health Professional Fact Sheet · checked 2026-09-16 · extracted
4. vite-c-03 · Position of an expert body · scoping review of national dietary surveys
   The α-tocopherol content is highest in sunflower oil followed by corn and rapeseed oil, olive oil and soybean oil.
   Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
5. vite-c-13 · Position of an expert body · scoping review of national dietary surveys
   In the recent dietary surveys from the Nordic and Baltic countries (20), the mean dietary intake of α-tocopherol among adult populations varied between 8.8 and 13.2 mg/day in Nordic countries and 7.8 and 13.9 mg/day in Baltic countries, with an overall average intake across countries of 12.2 mg/day.
   Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
6. vite-c-14 · Position of an expert body · scoping review
   Based on this, the EAR for α-tocopherol in humans was set on the basis of α-tocopherol depletion and repletion studies in men using erythrocyte hemolysis as the biomarker. The current RDA of 15 mg α-tocopherol was extrapolated from that value.
   Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
7. vite-c-19 · Position of an expert body · agency risk assessment
   Due to the evolution of the definition of ‘vitamin E’, the Panel notes that food composition data are not harmonised and sometimes ambiguous as to whether the ‘vitamin E’ content reported refers to α‐tocopherol only or include all tocochromanols. The lack of harmonisation regarding product labelling introduces further uncertainties.
   EFSA NDA Panel, Scientific opinion on the tolerable upper intake level for vitamin E, EFSA Journal 2024 (CC BY-ND 4.0) · checked 2026-09-21 · independently re-checked
8. vite-c-01 · Position of an expert body · agency fact sheet
   A given amount of synthetic alpha-tocopherol (all rac-alpha-tocopherol; commonly labeled as DL or dl) is therefore only half as active as the same amount (by weight in mg) of the natural form (RRR-alpha-tocopherol; commonly labeled as D or d). Most vitamin-E-only supplements provide ≥67 mg (100 IU of natural vitamin E) of the nutrient. These amounts are substantially higher than the RDAs.
   Vitamin E, Fact Sheet for Health Professionals, NIH Office of Dietary Supplements · checked 2026-09-21 · independently re-checked
9. vite-c-02 · Position of an expert body · agency fact sheet
   To convert from mg to IU: 1 mg of alpha-tocopherol is equivalent to 1.49 IU of the natural form or 2.22 IU of the synthetic form.
   Vitamin E, Fact Sheet for Health Professionals, NIH Office of Dietary Supplements · checked 2026-09-21 · independently re-checked
10. vite-c-04 · Position of an expert body · scoping review
    The absorption efficiency of α-tocopherol shows large variability with values ranging between 10 and 79% (2)...The presence of fat is required for an efficient absorption and the amount of fat provided in the meal determines α-tocopherols bio-accessibility, as fat facilitates its extraction from the food matrix, stimulates biliary secretion and promotes micelle formation (16).
    Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
11. vite-c-05 · Randomised controlled trial(s) · randomised crossover trial
    The α-tocopherol 0- to 10-h AUCs (AUCs0-10 h) in TRLs was higher (P < 0.05) for the HE trial (least-squares mean ± SE: 981 ± 162 nmol/L ⋅ 10 h) than for the LE (311 ± 162 nmol/L ⋅ 10 h) and CON (117 ± 162 nmol/L ⋅10 h) trials, which did not differ from one another.
    Kim et al., The Journal of Nutrition, 2016 · checked 2026-09-21 · independently re-checked
12. vite-c-06 · Randomised controlled trial(s) · randomised controlled pharmacokinetic trial
    Following the 2nd meal at 4 h, SME was 55% higher in the 0% group than in the 40% group (15.8% ± 1.1% compared with 10.2% ± 1.1%, P < 0.009), resulting in greater Cmax and AUC in the 0% group at 12 and 24 h (P < 0.04)...Compared with controls, the obese/MASLD cohort had 31% lower SME (0.87% ± 0.1% compared with 1.26% ± 0.1%, P = 0.047), resulting in reduced Cmax and AUC (P < 0.04) at 24 h.
    The Journal of Nutrition, 2026 · checked 2026-09-21 · independently re-checked
13. vite-c-07 · Position of an expert body · scoping review
    In the liver, out of all vitamin E forms, the protein α-TTP preferentially binds to α-tocopherol and is responsible for its further transportation, while the remaining tocochromanols are metabolised and excreted in the bile.
    Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
14. vite-05 · Position of an expert body · expert body statement
    Deficiency symptoms include peripheral neuropathy, ataxia, skeletal myopathy, retinopathy, and impairment of the immune response
    NIH Office of Dietary Supplements, Vitamin E - Health Professional Fact Sheet · checked 2026-09-16 · extracted
15. vite-c-15 · Position of an expert body · scoping review
    It is, however, difficult to interpret plasma or serum α-tocopherol concentrations. They largely depend on plasma lipid concentrations, which are known to increase with age and consequently cause an increase in plasma carriers for α-tocopherol, in turn leading to higher circulating α-tocopherol concentrations (3).
    Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
16. vite-06 · Position of an expert body · expert body statement
    People with Crohn's disease, cystic fibrosis, or an inability to secrete bile from the liver into the digestive tract, for example, often pass greasy stools or have chronic diarrhea
    NIH Office of Dietary Supplements, Vitamin E - Health Professional Fact Sheet · checked 2026-09-16 · extracted
17. vite-c-16 · Position of an expert body · agency lactation monograph
    Vitamin E is a normal component of human milk. Maternal obesity, smoking and possibly preterm birth (<37 weeks gestational age) are associated with lower milk vitamin E levels...Daily maternal vitamin E supplementation from prenatal multivitamins can safely and modestly increase milk vitamin E levels and improve the vitamin E status of the breastfed infant compared to no supplementation. Higher daily dosages have not been studied.
    Vitamin E, Drugs and Lactation Database (LactMed), NBK501922, NICHD / National Library of Medicine, версія 2026-09-01 · checked 2026-09-21 · independently re-checked
18. vite-08 · Position of an expert body · expert body statement
    Evidence to date is insufficient to support taking vitamin E to prevent cancer.
    NIH Office of Dietary Supplements, Vitamin E - Health Professional Fact Sheet · checked 2026-09-16 · extracted
19. vite-09 · Randomised controlled trial(s) · review of trials cited by expert body
    Results from an additional 1.5 years of follow-up from this trial (during which the subjects no longer received vitamin E or selenium), showed that the men who had taken the vitamin E had a 17% increased risk of prostate cancer compared to men only taking placebos, a statistically significant difference.
    NIH Office of Dietary Supplements, Vitamin E - Health Professional Fact Sheet · checked 2026-09-16 · extracted
20. vite-t1 · Randomised controlled trial(s) · randomised controlled trial
    In the modified intention-to-treat population, 29.3% of participants in the vitamin E group achieve the primary outcome compared with 14.1% in the placebo group.
    Wang et al., Cell Reports Medicine, 2025 · checked 2026-09-16 · independently re-checked
21. vite-t2 · Meta-analysis or systematic review · systematic review
    Ascorbic acid and a high dose of vitamin E, when given separately, also showed positive effects on cognitive performance, but there is not sufficient evidence to support their use.
    Ramirez et al., Nutrients, 2022 · checked 2026-09-16 · independently re-checked
22. vite-r5-2 · Meta-analysis or systematic review · meta-analysis of randomised controlled trials
    Compared with controls, when vitamin E was given alone it did not reduce the incidence of ischemic and hemorrhagic stroke. Conversely, compared with controls, supplementation of vitamin E with other antioxidants reduced ischemic stroke (random effects, RR: 0.91; 95% CI: 0.84-0.99; P = 0.02) but with a significant increase in hemorrhagic stroke (random effects, RR: 1.22; 95% CI: 1.0-1.48; P = 0.04).
    Maggio et al., Nutrition Reviews, 2024 · checked 2026-09-17 · independently re-checked
23. vite-r5-3 · Meta-analysis or systematic review · umbrella review of meta-analyses of randomised controlled trials
    By pooling ES based on the random-effects model, we found that vitamin E supplementation significantly decreased ALT (ES -6.47, 95% CI -11.73 to -1.22, P = 0.01), AST (ES -5.35, 95% CI -9.78 to -0.93, P = 0.01), degrees of fibrosis (ES -0.24, 95% CI -0.36 to -0.12, P < 0.001) and steatosis (ES -0.67, 95% CI -0.88 to -0.45, P < 0.001) in NAFLD patients, but had no effect on GGT.
    Wang et al., Journal of Digestive Diseases, 2023 · checked 2026-09-17 · independently re-checked
24. vite-r5-4 · Randomised controlled trial(s) · randomised controlled trial
    More patients on combination therapy achieved the primary outcome versus placebo (54% vs. 19%, P = 0.003) but not with vitamin E alone (31% vs. 19%, P = 0.26). Both groups showed improvements in resolution of NASH compared with placebo (combination group: 43% vs. 12%, P = 0.005; vitamin E alone: 33% vs. 12%, P = 0.04).
    Bril et al., Diabetes Care, 2019 · checked 2026-09-17 · independently re-checked
25. vite-r5-5 · Observational data · meta-analysis of cohort studies and randomised controlled trials
    The pooled RR for vitamin E supplemental and risk of AD was 0.81 [95% CI: 0.50-1.33, I 2 = 69.2%]. Suitable data could not be extracted to do meta-analysis as there was no unified standard of outcome measure for studies on AD progression.
    Wang et al., Nutritional Neuroscience, 2021 · checked 2026-09-17 · independently re-checked
26. vite-c-08 · Meta-analysis or systematic review · meta-analysis of clinical trials
    In the meta-analysis of 6 studies that reported changes in oxidized LDL levels, a significant decrease in LDL oxidation was observed (95% CI: -1.44 [-2.5, -0.38]; I2 = 95.8%, P < 0.001; Tau-squared: 1.6171). Moreover, a meta-analysis of 7 studies that reported lag time as a measure of LDL oxidation showed that vitamin E supplementation significantly increased the lag time of LDL oxidation (95% CI: 20.45 [12.46, 28.43]; I2 = 95.9%, P < 0.001; Tau-squared: 103.3545).
    European Journal of Pharmacology, 2025 · checked 2026-09-21 · independently re-checked
27. vite-04 · Position of an expert body · expert body statement
    High doses of alpha-tocopherol supplements can cause hemorrhage and interrupt blood coagulation in animals.
    NIH Office of Dietary Supplements, VitaminE - Health Professional Fact Sheet · checked 2026-09-16 · extracted
28. vite-r5-1 · Meta-analysis or systematic review · dose-response meta-analysis of randomised controlled trials
    The pooled all-cause mortality risk difference in high-dosage vitamin E trials was 39 per 10,000 persons (95% CI, 3 to 74 per 10,000 persons; P = 0.035). For low-dosage vitamin E trials, the risk difference was -16 per 10,000 persons (CI, -41 to 10 per 10,000 persons; P > 0.2).
    Miller et al., Annals of Internal Medicine, 2005 · checked 2026-09-17 · independently re-checked
29. vite-c-09 · Position of an expert body · scoping review
    The toxicity of natural α-tocopherol is low, due to efficient metabolic control that prevents any excess accumulation of the vitamin in the body. No adverse effects have been described from intakes provided by food sources...Further, consumption of high-dose α-tocopherol supplements (≥300 mg/d) may lead to interactions with drugs such as aspirin, warfarin, tamoxifen and cyclosporine A and may alter their activities (29).
    Nordic Nutrition Recommendations 2023 scoping review, Food & Nutrition Research, 2023 · checked 2026-09-21 · independently re-checked
30. vite-c-10 · Position of an expert body · agency fact sheet
    Doses of up to 1,000 mg/day (1,500 IU/day of the natural form or 1,100 IU/day of the synthetic form) in adults appear to be safe, although the data are limited and based on small groups of people taking up to 3,200 mg/day of alpha-tocopherol for only a few weeks or months.
    Vitamin E, Fact Sheet for Health Professionals, NIH Office of Dietary Supplements · checked 2026-09-21 · independently re-checked
31. vite-c-11 · Position of an expert body · agency fact sheet reporting randomised controlled trials
    Two clinical trials have found an increased risk of hemorrhagic stroke in participants taking alpha-tocopherol; one trial included Finnish male smokers who consumed 50 mg/day for an average of 6 years [53] and the other trial involved a large group of male physicians in the United States who consumed 400 IU (180 mg) of synthetic vitamin E every other day for 8 years [26].
    Vitamin E, Fact Sheet for Health Professionals, NIH Office of Dietary Supplements · checked 2026-09-21 · independently re-checked
32. vite-c-12 · Position of an expert body · agency fact sheet
    Research has not found any adverse effects from consuming vitamin E in food [6].
    Vitamin E, Fact Sheet for Health Professionals, NIH Office of Dietary Supplements · checked 2026-09-21 · independently re-checked
33. vite-c-17 · Position of an expert body · agency risk assessment
    The Panel therefore considers that all stereoisomers can be expected to have a similar activity in relation to the risk of bleeding. Despite this progress in mechanistic understanding, the Panel found no basis to change the UL previously established by the SCF. Considering the totality of the available evidence and related uncertainties (Section 3.4 ), the Panel thus retains the UL previously established by the SCF of 300 mg α‐tocopherol/day for adults.
    EFSA NDA Panel, Scientific opinion on the tolerable upper intake level for vitamin E, EFSA Journal 2024 (CC BY-ND 4.0) · checked 2026-09-21 · independently re-checked
34. vite-c-18 · Position of an expert body · agency risk assessment
    In the absence of specific data on younger age groups, the SCF derived UL for children and adolescents, aged 1–17 years, by extrapolating the adult UL using allometric scaling (body weight0.75). No new evidence was found investigating adverse effects of α‐tocopherol supplementation in these age groups.
    EFSA NDA Panel, Scientific opinion on the tolerable upper intake level for vitamin E, EFSA Journal 2024 (CC BY-ND 4.0) · checked 2026-09-21 · independently re-checked
35. vite-07 · Position of an expert body · expert body statement
    As a result, taking large doses with anticoagulant or antiplatelet medications, such as warfarin (Coumadin), can increase the risk of bleeding, especially in conjunction with low vitamin K intake.
    NIH Office of Dietary Supplements, Vitamin E - Health Professional Fact Sheet · checked 2026-09-16 · extracted