"One might expect that in nature we would find the complete vitamin E family of tocopherols and tocotrienols together in various plants, especially since some companies produce vitamin E supplements that contain both the tocopherols and tocotrienols. Nothing could be further from the truth. The fact is, plants widely differ in their vitamin E proportions, and no single plant provides the entire vitamin E family in nutritionally adequate amounts. Annatto beans, for instance, are higher in tocotrienols but contain no tocopherols. Sunflower, peanut, walnut, sesame and olive oils contain significant amounts of the tocopherols, yet are virtually void of the tocotrienols.6
Even within the categories of plants that predominate in either tocopherols or tocotrienols, we find large variances in their specific alpha, beta, gamma, and delta proportions. For example, annatto is high in delta tocotrienol with moderate amounts of gamma tocotrienol. In oat and barley, alpha tocotrienol predominates. In hulled and de-hulled wheat, beta-tocotrienol is the predominate isomer.7
Thus, while tocopherols and tocotrienols both exist in nature, plants differ widely in their vitamin E proportions. This little-known fact radically changes the way we look at “naturally occurring” vitamin E and has important implications in vitamin E supplementation.
Companies that seek to provide the entire vitamin E family in one product derive the tocopherols and tocotrienols from separate plant sources (a review of the ingredient label should confirm this). Such products are typically developed by processing the tocotrienols (usually from palm or rice bran) into the tocopherols (usually from soy). While there are a few products that do provide the full range of tocopherols and tocotrienols without using separate sources, they provide only trivial amounts of portions of the vitamin E complex and are unable to deliver dose-dependant benefits such as the inhibition of c-reactive protein, a potent bio marker and mediator of Cardiovascular Disease.8 "
http://acgrace.com/what-are-tocotrienols.html
On that same page:
“Tocopherols, mainly alpha tocopherol, hinder the assimilation of tocotrienols in the human body.9 This is due to the preferential uptake of tocopherol via the tocopherol-transfer protein,10 which discriminates between tocopherols and tocotrienols.11 Thus, combining tocotrienols and tocopherols together does not appear to be efficacious.”
Which brings you to:
9 Packer L, Weber SU, Rimbach G. J Nutr. 2001 Feb; 131(2):369S-73S. Molecular aspects of alpha-tocotrienol antioxidant action and cell signalling.
10 Arita M., Sato Y., Miyata A., Tanabe T., Takahashi E., Kayden H. J., Arai H., Inoue K. Biochem. J. 1995;306:437-443. Human alpha-tocopherol transfer protein: cDNA cloning, expression and chromosomal localization.
11 Packer L, Weber SU, Rimbach G. J Nutr. 2001 Feb;131(2):369S-73S. Molecular aspects of alpha-tocotrienol antioxidant action and cell signalling.