Vitamin E

What it is

Vitamin E is a collective term for several fat-soluble compounds, above all the tocopherols. Studies and reference values usually refer to alpha-tocopherol. As additives, tocopherols are approved under the numbers E306 to E309 and protect oils and fats from going rancid.

Good natural sources are vegetable oils, nuts and seeds. Wheat germ oil provides 20.3 mg per tablespoon, more than the D-A-CH societies estimate as the daily intake: 11 to 15 mg for adults. EFSA sets 11 mg for women and 13 mg for men. According to the German National Nutrition Survey, adult women in Germany have a median intake of 11.3 to 12.7 mg.

How it works

Vitamin E sits in the cell membranes and scavenges free radicals there before they attack the sensitive polyunsaturated fatty acids. That is why requirements rise when someone eats a lot of these fatty acids. The only authorized EU health claim for vitamin E is also based on this protection against oxidative stress.

In fatty liver disease, oxidative stress is a driver of inflammation. This is where the hope comes in that an antioxidant could relieve the liver. Similarly in Alzheimer’s disease, where free radicals are considered part of the disease process.

Natural or synthetic

On labels, vitamin E is often stated in International Units. The conversion depends on the form. For natural vitamin E, RRR-alpha-tocopherol, 1 IU corresponds to 0.67 mg. For synthetic all-rac-alpha-tocopherol, 1 IU corresponds to only 0.45 mg. The BfR converts 400 IU into 268 mg. Anyone reading studies should therefore pay attention to which form was used. SELECT, for example, used synthetic vitamin E.

A true deficiency is rare in healthy people. Those at risk are mainly people with disorders of fat digestion, for example in Crohn’s disease or cystic fibrosis.

What the studies show

PIVENS: vitamin E in steatohepatitis

247 adults with nonalcoholic steatohepatitis and without diabetes received 800 IU vitamin E, 30 mg pioglitazone or placebo for 96 weeks. The liver was biopsied before and after treatment. Under vitamin E the findings improved in 43 percent, under placebo in 19 percent; the primary endpoint was reached. Pioglitazone missed it. Fibrosis, that is, the conversion to scar tissue, did not improve significantly under either agent.

TEAM-AD: daily functioning in Alzheimer’s disease

613 patients with mild to moderate Alzheimer’s dementia from 14 veterans’ clinics received, in addition to their standard therapy, 2000 IU alpha-tocopherol, memantine, both or placebo. After a mean of 2.27 years, patients on vitamin E had lost 3.15 points less in daily living skills than those on placebo. This corresponds to 19 percent slower progression per year. Caregiver time increased least under vitamin E. Memantine and the combination showed no significant effect.

SELECT: the setback

35,533 healthy men took 400 IU synthetic vitamin E, selenium, both or placebo daily. The aim was to prevent prostate cancer. The opposite occurred: 620 cases under vitamin E versus 529 under placebo, a 17 percent higher risk. In absolute terms, that was 1.6 additional cases per 1,000 person-years.

Where the data stop

The hope from observational studies that vitamin E protects the heart was not confirmed in large studies. In HOPE with 9,541 high-risk patients, in the Women’s Health Study with 39,876 women over 10.1 years and in the Physicians’ Health Study II with 14,641 men, vitamin E did not reduce the rate of major cardiovascular events. The Women’s Health Study did find 24 percent fewer cardiovascular deaths, but that was not its primary aim. There are limits in fatty liver disease too: scarring did not improve, and PIVENS excluded people with diabetes. Many later meta-analyses, for example of 12 studies with 794 patients, rely mainly on liver values rather than biopsies. For respiratory infections in the nursing home, only the proportion of people with upper respiratory tract infections fell. How often and for how long someone was ill did not change, nor did lower respiratory tract infections or antibiotic use. In AREDS, vitamin E was only one building block of a combination; its own contribution cannot be read from it. In Alzheimer’s disease, the benefit rests on a single study, cognition itself did not improve, and in mild cognitive impairment vitamin E did not prevent the transition to dementia. The BfR states that no health benefits of an intake above physiological requirements can be derived from the data. The positive studies concerned people with a disease.

Status, approval and legal

Vitamin E is an approved nutrient and may be used in food supplements. The BfR proposes 30 mg per daily dose of a preparation, which corresponds to 200 percent of the D-A-CH estimated value for young men. According to the EU Scientific Committee on Food, the tolerable upper intake level for total intake is 300 mg per day. The authorized health claim is that vitamin E contributes to the protection of cells from oxidative stress. Vitamin E is not on the WADA Prohibited List for 2026.

Safety

From food, vitamin E is harmless. At high doses as a supplement, however, there are clear signals. In SELECT, the risk of prostate cancer rose by 17 percent under 400 IU, which is why the BfR recommends specifically informing men aged 55 and over about it. A meta-analysis of 9 studies with 118,765 participants found 22 percent more brain hemorrhages and 10 percent fewer strokes caused by vascular occlusion. In absolute terms, that was one additional brain hemorrhage per 1,250 users. According to the BfR, this risk already appeared at about 130 to 200 mg per day. An older meta-analysis saw slightly increased mortality from 400 IU daily, though mainly in studies with chronically ill people. Anyone taking anticoagulants such as warfarin has a higher risk of bleeding from 400 IU daily. During chemotherapy or radiotherapy, high-dose antioxidants can weaken the treatment. High doses therefore belong under medical supervision, as in the studies.

Sources

• Sanyal et al., Pioglitazone, vitamin E, or placebo for nonalcoholic steatohepatitis, New England Journal of Medicine 2010
• Dysken et al., Effect of vitamin E and memantine on functional decline in Alzheimer disease: the TEAM-AD VA cooperative randomized trial, JAMA 2014
• Farina et al., Vitamin E for Alzheimer’s dementia and mild cognitive impairment, Cochrane Database of Systematic Reviews 2017
• Meydani et al., Vitamin E and respiratory tract infections in elderly nursing home residents, JAMA 2004
• Klein et al., Vitamin E and the risk of prostate cancer: SELECT, JAMA 2011
• Lee et al., Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women’s Health Study, JAMA 2005
• HOPE Study Investigators, Vitamin E supplementation and cardiovascular events in high-risk patients, New England Journal of Medicine 2000
• Schürks et al., Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials, BMJ 2010
• BfR, Proposed maximum levels for vitamin E in foods including food supplements, 2021 (German)
• NIH Office of Dietary Supplements, Vitamin E Fact Sheet for Health Professionals