1 2 Wagner, Karl-Heinz; Afaf Kamal-Eldin; Ibrahim Elmadfa (2004). "Gamma-tocopherol--an underestimated vitamin?". Annals of nutrition and metabolism. 48 (3): 169–88. doi:10.1159/000079555. PMID15256801. In North America, the intake of γ-tocopherol has been estimated to exceed that of α-tocopherol by a factor of 2–4 ... due to the fact that soybean oil is the predominant vegetable oil in the American diet (76.4%) followed by corn oil and canola oil (both 7%) ... The supply of dietary fats ... is much more diverse in Europe ... The oils mainly consumed in Europe, i.e. sunflower, olive and canola oil, provide less γ-tocopherol but more α-tocopherol ... [T]he ratio of α-:γ-tocopherol is at least 1:2. Therefore, the average γ-tocopherol intake can be estimated as 4–6 mg/day, which is about 25–35% of the USA intake. In accordance with the lower estimated European intake of γ-tocopherol, the serum levels of γ-tocopherol in European populations are 4–20 times lower than that of α-tocopherol
↑ Jiang, Q; Christen, S; Shigenaga, MK; Ames, BN (2001). "gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention". The American Journal of Clinical Nutrition. 74 (6): 714–22. PMID11722951.
