Alpha-tocopherol
The synthetic form of vitamin E, added to fats and oils to stop them going rancid. At food-additive levels it functions as an antioxidant.
At very high supplemental doses, not food-additive levels, alpha-tocopherol can slow blood clotting and has been linked to higher all-cause mortality in multiple RCTs. The risk is from high-dose supplements, not from food.
What is it?
Alpha-tocopherol is the most biologically active form of vitamin E. As an additive (E307) it is typically the synthetic form (dl-alpha-tocopherol), which differs slightly in structure from the naturally occurring d-alpha-tocopherol found in nuts, seeds and plant oils. It belongs to a family of fat-soluble antioxidants.
What does it do?
Alpha-tocopherol breaks the chain reaction that turns fats rancid (lipid peroxidation). It donates a hydrogen atom to free radicals that would otherwise attack the fat molecules in food. This extends shelf life and prevents off-flavours. In the body, it also serves as a key fat-soluble antioxidant protecting cell membranes.
Where you will see it
Most common in margarines, vegetable oils, infant formula, processed meats, dried milk, breakfast cereals, and fat-based spreads. It is also widely used in supplements and baby food. On a label it appears as E307 or alpha-tocopherol.
What the science says
High-dose supplements and all-cause mortality
Multiple large randomised trials and a meta-analysis of 19 RCTs (covering around 136,000 people) found that taking high-dose vitamin E supplements (400 IU per day or above) was associated with a small but statistically significant increase in all-cause mortality. This finding applies to supplementation far above what any food additive use could deliver. Dietary vitamin E from food is associated with the opposite pattern, lower rather than higher mortality.
A meta-analysis of 19 RCTs (n=135,967) found that high-dose vitamin E supplementation at or above 400 IU per day was associated with increased all-cause mortality.
Higher circulating blood levels of alpha-tocopherol from dietary sources are associated with lower all-cause mortality, contrasting with the supplementation finding.
Blood clotting: the critical adverse effect at high doses
EFSA's 2015 re-evaluation identified prolonged coagulation time as the critical adverse effect of high-dose tocopherol intake. This means blood takes longer to clot, which is relevant for people on anticoagulant medication. The panel found available data too limited to set a formal acceptable daily intake, though food-additive exposure was not considered to be of safety concern.
The critical adverse effect of high-dose alpha-tocopherol is prolonged coagulation time. EFSA concluded available data were insufficient to set a numerical ADI for the tocopherols.
Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study
The ATBC trial, a large Finnish RCT in male smokers, gave participants 50 mg per day of synthetic alpha-tocopherol. It found no benefit for lung cancer prevention and raised questions about increased haemorrhagic stroke. Higher baseline serum vitamin E levels in the same cohort were associated with lower cancer mortality, illustrating the complexity of separating dietary from supplemental effects.
In the ATBC study of 29,133 male smokers, supplemental alpha-tocopherol (50 mg/day) did not reduce lung cancer incidence and was associated with a modest increase in haemorrhagic stroke.
Where it stands with the regulators
Who should be careful
People taking anticoagulant medication such as warfarin should be aware that high vitamin E intake from supplements can increase bleeding risk. This applies to supplements, not to the small amounts from food additives. Look for E307 or alpha-tocopherol on the label if tracking total vitamin E intake alongside supplements.
The honest read
The science distinguishes sharply between dietary vitamin E and high-dose supplements. From food, including food additives, exposure to alpha-tocopherol is associated with neutral to beneficial outcomes in the published literature. From supplements at 400 IU per day or above, the picture changes: a meta-analysis of 136,000 people found a small but real increase in all-cause mortality. The mechanism is not fully understood, and the dose that is problematic is far above what any food additive use delivers. EFSA found insufficient data to set a clean acceptable daily intake, which is a genuine data gap rather than a finding of harm. The coagulation effect at high doses is real and relevant for people on blood thinners. The science on this additive at food-use levels is not alarming, but it is not simple either, because the same molecule at much higher doses carries a documented risk.
Related additives
Common questions
Is E307 banned in the UK?
No. E307 is approved for use in the UK under the assimilated EU Regulation 1333/2008 and the UK FSA approved-additives list. It is permitted in a range of foods including fats, oils, margarines and infant formula.
Can high-dose vitamin E supplements cause harm?
Yes. A meta-analysis of 19 randomised trials covering around 136,000 people found that taking 400 IU or more of vitamin E per day from supplements was associated with a small but statistically significant increase in all-cause mortality. EFSA also identified prolonged blood-clotting time as the critical adverse effect of high doses. Food-additive levels are far below the doses used in those trials.
What foods contain E307?
E307 is most commonly found in margarines, vegetable oil-based spreads, infant formula, processed meats, dried milk products, and some breakfast cereals. It appears on the label as E307 or alpha-tocopherol.
Is E307 vegan?
As a food additive, E307 is synthetic alpha-tocopherol and is not derived from animal sources, so it is suitable for vegans. However, the carrier solvents or other ingredients in a product may not be. Check the full ingredient list.
Sources
- EFSA Scientific Opinion on the re-evaluation of tocopherol-rich extract (E 306), alpha-tocopherol (E 307), gamma-tocopherol (E 308) and delta-tocopherol (E 309) as food additives, EFSA Journal 2015;13(9):4247
- Miller ER et al. Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality. Annals of Internal Medicine, 2005
- The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. New England Journal of Medicine, 1994
- Relationship Between Serum Alpha-Tocopherol and Overall and Cause-Specific Mortality. Circulation Research, 2019
- UK FSA Approved Additives and E Numbers
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