Trial reportProceedings of the National Academy of Sciences of the United States of America1994
Human plasma vitamin E kinetics demonstrate rapid recycling of plasma RRR-alpha-tocopherol.
Trial report in Proceedings of the National Academy of Sciences of the United States of America, 1994. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT00862433 (Vitamin E Pharmacokinetics and Biomarkers in Normal and Obese Women), which is not on this map. Cited by 31 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Vitamin E Pharmacokinetics and Biomarkers in Normal and Obese Women
Who cites it
31 citing papers in PubMed, 156 citations in OpenAlex.
- Vitamin E absorption and kinetics in healthy women, as modulated by food and by fat, studied using 2 deuterium-labeled α-tocopherols in a 3-phase crossover design.The American journal of clinical nutrition · 2019Trial
- Metabolic syndrome increases dietary α-tocopherol requirements as assessed using urinary and plasma vitamin E catabolites: a double-blind, crossover clinical trial.The American journal of clinical nutrition · 2017Trial
- Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial.The Journal of physiology · 2014Trial
- Plasma zinc, vitamin B(12) and α-tocopherol are positively and plasma γ-tocopherol is negatively associated with Hb concentration in early pregnancy in north-west Bangladesh.Public health nutrition · 2013Trial
- Double-balloon jejunal perfusion to compare absorption of vitamin E and vitamin E acetate in healthy volunteers under maldigestion conditions.European journal of clinical nutrition · 2013Trial
- Sex differences in the inhibition of gamma-tocopherol metabolism by a single dose of dietary sesame oil in healthy subjects.The American journal of clinical nutrition · 2008Trial
- Alpha- and gamma-tocotrienols are metabolized to carboxyethyl-hydroxychroman derivatives and excreted in human urine.Lipids · 2001Trial
- Scientific opinion on the tolerable upper intake level for vitamin E.EFSA journal. European Food Safety Authority · 2024Article
- Human Vitamin E deficiency, and what is and is not Vitamin E?Free radical biology & medicine · 2024Review
- Epigenetic Regulation of NRF2/KEAP1 by Phytochemicals.Antioxidants (Basel, Switzerland) · 2020Review
- Trends of Lipophilic, Antioxidant and Hematological Parameters Associated with Conventional and Electronic Smoking Habits in Middle-Age Romanians.Journal of clinical medicine · 2019Article
- Antioxidant Tocols as Radiation Countermeasures (Challenges to be Addressed to Use Tocols as Radiation Countermeasures in Humans).Antioxidants (Basel, Switzerland) · 2018Review
- Complexity of vitamin E metabolism.World journal of biological chemistry · 2016Review
- The nutrigenetic influence of the interaction between dietary vitamin E and TXN and COMT gene polymorphisms on waist circumference: a case control study.Journal of translational medicine · 2015Article
- Scientific Opinion on Dietary Reference Values for vitamin E as α-tocopherol.EFSA journal. European Food Safety Authority · 2015Article
- Biomass and RRR-α-tocopherol production in Stichococcus bacillaris strain siva2011 in a balloon bioreactor.Microbial cell factories · 2014Article
- Can supplementation with vitamin C and E alter physiological adaptations to strength training?BMC sports science, medicine & rehabilitation · 2014Article
- This kinetic, bioavailability, and metabolism study of RRR-α-tocopherol in healthy adults suggests lower intake requirements than previous estimates.The Journal of nutrition · 2012Article
- Vitamins C and E: beneficial effects from a mechanistic perspective.Free radical biology & medicine · 2011Review
- Quantitation of [5-14CH3]-(2R, 4'R, 8'R)-α-tocopherol in humans.The Journal of nutrition · 2011Article
Corrections and comments
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
A kinetic model of vitamin E transport in humans is described using data from our studies with deuterium-labeled stereoisomers of alpha-tocopherol (RRR- and SRR-). In normal subjects, both alpha-tocopherols are present at similar concentrations in chylomicrons, but by 24 hr, RRR-alpha-tocopherol is at higher plasma concentrations because RRR-alpha-tocopherol is preferentially incorporated into very low density lipoproteins, which are then secreted into plasma. In three nondiscriminator patients with familial isolated vitamin E deficiency, the fractional disappearance rates (mean +/- SD) of deuterium-labeled RRR- and SRR-alpha-tocopherols in plasma were 1.4 +/- 0.6 and 1.3 +/- 0.3 pools per day, respectively (difference, 0.1 +/- 0.3). In these patients, plasma concentrations of both RRR- and SRR-alpha-tocopherols decreased similarly to SRR-alpha-tocopherol in controls. In six controls, fractional disappearance rates of deuterium-labeled RRR-alpha-tocopherol (0.4 +/- 0.1 pool per day) were significantly (P < 0.01) slower than for SRR- (1.2 +/- 0.6). The differences (0.8 +/- 0.6 pool per day) between these two rates in controls estimate the rate at which RRR-alpha-tocopherol, which had left the plasma, was returned to the plasma. Although plasma labeled RRR-alpha-tocopherol concentrations in controls appear to change slowly, these data show that both RRR- and SRR-alpha-tocopherols leave the plasma rapidly, but only RRR-alpha-tocopherol is returned to the plasma, likely in nascent very low density lipoproteins. This recycling of RRR-alpha-tocopherol accounts for nearly 1 pool of alpha-tocopherol per day.
Indexed as
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.