Vitamin E
Fat-soluble, and the natural form does more per milligram than the synthetic one.
Vitamin E is the body's main fat-soluble antioxidant, protecting cell membranes from oxidative damage, and it needs to be taken with a meal containing some fat to absorb properly. The natural form, d-alpha-tocopherol, has roughly twice the biological activity of the synthetic dl-alpha-tocopherol on a milligram-for-milligram basis, because half of the synthetic version is a mirror-image molecule the body uses less efficiently. Mixed tocopherols provide a broader spread including gamma-tocopherol, while tocotrienols are a structurally distinct, less-studied family with emerging interest of their own.
Reference values
Daily reference values from official nutrition authorities. These are population reference figures, not personal recommendations.
| RDA | Upper limit | Source |
|---|---|---|
| 15 mg | 1000 mg | UK |
Forms and bioavailability
Not all forms are absorbed equally. The form on your supplement label affects how much your body can actually use.
| Form | Absorption | With food | Timing | Evidence |
|---|---|---|---|---|
| d-alpha-tocopherol (natural) | Higher | With food | Either | Likely |
| dl-alpha-tocopherol (synthetic) | Typical | With food | Either | Likely |
| mixed tocopherols | Typical | With food | Either | Likely |
| tocotrienols | Typical | With food | Either | Possible |
Stack Almanac tracks which vitamin E form you're taking so the natural-versus-synthetic difference is reflected in your totals, not treated as one interchangeable milligram figure.
Track your Vitamin E in Stack Almanac
Last reviewed: 2026-07-08. Reference values are adult-general RDAs from UK. Individual needs may vary. This page is for informational purposes only and is not a substitute for professional medical advice.