It appears that the story on vitamin E and its role in human health remains incomplete. It is apparent that vitamin E supplementation involves many variables, some of which include its uptake from the intestine, the preference for α-tocopherol, transport by tocopherol specific proteins and lipid transporters and the differential metabolism of different vitamin E isoforms. The fundamental differences within population genetics can have significant implications for the effect that dietary supplementation might have on human health. When evaluating the efficacy of vitamin E prophylactic or therapeutic use in previous and future studies, it is critical to consider dosage to be administered, form of vitamin E and source (such as whether from synthetic or purified from natural sources). Further studies are needed to determine the effects of all vitamin E isoforms on cell growth, tumorigenicity, to clarify its possible use as an adjuvant to existing chemotherapeutics. The Alpha-Tocopherol, Beta Carotene (ATBC) Cancer Prevention Study Group and Selenium and Vitamin E Cancer Prevention Trial (SELECT) studies along with the numerous studies of vitamin E should help guide the next chapter of vitamin E research.
Keywords: ABCA1; ATBC; ATP-binding cassette A1; Antioxidant; Cancer prevention; Cancer therapy; HDL; LDL; NPC1L1; NSCLC; Niemann-Pick C1-like 1; PKC; PUFA; ROS; SELECT; SR-BI; TAP; TRF; TTP; Tocopherol; Tocopherol associated protein; Tocotrienol; VLDL; Vitamin E transport proteins; alpha-tocopherol, beta-carotene; high density lipoproteins; low density lipoproteins; non-small cell lung cancer; polyunsaturated fatty acids; protein kinase C; reactive oxygen species; scavenger receptor class B type 1; selenium and vitamin E cancer prevention trial; tocopherol transfer protein; tocotrienol rich fraction; very low density lipoprotein.
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