The compounds that make up vitamin E consist of two different types of molecule, tocopherols and tocotrienols. Each of those comes in four variants -- alpha, beta, gamma and delta -- each with a slightly different structure. Of the eight, only the alpha-tocopherol version is actively used by the human body. The remainder are filtered out by the liver and excreted in waste products. The alpha-tocopherol form of vitamin E is the one that's predominant in hazelnuts and their oil.
A 100-gram portion of hazelnuts contains 15.03 milligrams of alpha-tocopherol, second only to the 25.87 milligrams in almonds. In more practical terms, a 1-ounce snack portion of hazelnuts provides 4.2 milligrams of vitamin E, or 20 percent of your daily value. A study published in 2012 in the European Journal of Lipid Science and Technology found similar levels of alpha-tocopherol in multiple samples of hazelnut oil.
Hazelnuts have a number of benefits aside from their vitamin E content. They're also a source of B vitamins, notably thiamine, and a number of minerals. Just 1 ounce of hazelnuts contains 86 percent of your DV for manganese, used in the production of sex hormones and the metabolism of fat. They're also a good source of copper, magnesium and iron.
Matthäus, B., & Özcan, M. M. (2012). The Comparison of Properties of The Oil and Kernels of Various Hazelnuts from Germany and Turkey. European Journal of Lipid Science and Technology, 114(7), 801–806. doi: 10.1002/ejlt.201100299
Nutrition Comparison of Hazelnuts vs Almonds vs Walnut. (n.d.).
Thomas, R. G., & Gebhardt, S. E. (n.d.). Nuts and Seeds as Sources of Alpha and Gamma Tocopherols. USDA-ARS Nutrients Data Laboratory.
Vitamin E - Fact Sheet for Health Professionals. (2019, July 10).