Vitamin E–drug interactions: molecular basis and clinical relevance

@article{Podszun2014VitaminEI,
  title={Vitamin E–drug interactions: molecular basis and clinical relevance},
  author={Maren Podszun and Jan Frank},
  journal={Nutrition Research Reviews},
  year={2014},
  volume={27},
  pages={215 - 231}
}
Vitamin E (α-, β-, γ- and δ-tocopherol and -tocotrienol) is an essential factor in the human diet and regularly taken as a dietary supplement by many people, who act under the assumption that it may be good for their health and can do no harm. With the publication of meta-analyses reporting increased mortality in persons taking vitamin E supplements, the safety of the micronutrient was questioned and interactions with prescription drugs were suggested as one potentially underlying mechanism… 
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The benefit of vitamin E as a treatment for neurodegenerative disorders is still under debate and this review focuses on those studies that mostly have contributed to clarifying the exclusive function of Vitamin E in relation to brain ageing and AD.
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Vitamin E family, composed by tocopherols and tocotrienols, is a group of compounds with neuroprotective properties. The exact role in the pathogenesis and the benefit of vitamin E as treatment for
A major component of vitamin E, &agr;‐tocopherol inhibits the anti‐tumor activity of crizotinib against cells transformed by EML4‐ALK
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References

SHOWING 1-10 OF 106 REFERENCES
Vitamin E Supplementation and Hepatic Drug Metabolism in Humans
TLDR
Findings do not support the hypothesis that α-TOH supplementation interferes with hepatic CYP3A4-mediated drug metabolism, and high-dose vitamin E may be associated with increased mortality in some populations.
Adverse effects of vitamin E by induction of drug metabolism
TLDR
Vitamin E did not provide benefits to patients with cardiovascular diseases, cancer, diabetes or hypertension, and it is recommended to work out at which threshold the drug-metabolizing system can be induced in humans before new trials with high dosages of vitamin E are started.
High-dose supplementation with natural α-tocopherol does neither alter the pharmacodynamics of atorvastatin nor its phase I metabolism in guinea pigs.
TLDR
Investigation of the pharmacodynamics of the lipid-lowering drug atorvastatin (ATV), a CYP3A4 substrate, in response to high-dose α-tocopherol (αT) feeding and determined protein expression and activities of relevant CYP found no differences.
How Safe is Vitamin E Supplementation?
TLDR
An overview of the earlier literature on vitamin E is provided, including a critical assessment of three meta-analyses that were neutral or negative toward vitamin E supplementation, and some guidance is offered for healthcare professionals to give to the general, healthy public and those with chronic conditions who are no doubt left puzzled about what to do regarding vitamin E supplements.
Effect of vitamin E supplementation on vitamin K status in adults with normal coagulation status.
TLDR
High-dose vitamin E supplementation increased PIVKA-II in adults not receiving oral anticoagulant therapy, but high doses of vitamin E may antagonize vitamin K.
Vitamins E and C are safe across a broad range of intakes.
TLDR
Clinical trial evidence is concluded that vitamin E supplements appear safe for most adults in amounts </=1600 IU (1073 mg RRR-alpha-tocopherol or the molar equivalent of its esters) and that vitamin C supplements of </=2000 mg/d are safe forMost adults.
Assessment of the safety of high-dose, short-term supplementation with vitamin E in healthy older adults.
TLDR
Short-term supplementation with 800 mg vitamin E/d has no adverse effect on healthy older adults and did cause a significant increase in serum vitamin E, and a small but significant (P < 0.05) increase in plasma zinc in the vitamin E-supplemented group.
Do tocotrienols have potential as neuroprotective dietary factors?
TLDR
The studies reviewed here support the notion that they may have potential as neuroprotective agents, however, experiments in relevant animal models and randomised human intervention trials addressing the neuroprotection mediated by T(3) are scarce and, thus, highly warranted.
Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality
TLDR
This meta-analysis of 19 randomized, controlled trials involving more than 135000 participants found that high-dosage vitamin E supplementation (400 IU/d for at least 1 year) increased all-cause mortality.
Effects of vitamin E on cholesterol levels of hypercholesterolemic patients receiving statins.
TLDR
Vitamin E supplementation did not affect total or low-density-lipoprotein cholesterol levels in hypercholesterolemic patients receiving lovastatin or simvastatin and neither cytochrome P-450 isoenzyme (CYP) 3A nor cholesteryl ester transfer protein (CETP) activity was significantly altered during the study.
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