Trial reportLipids2001
Alpha- and gamma-tocotrienols are metabolized to carboxyethyl-hydroxychroman derivatives and excreted in human urine.
Trial report in Lipids, 2001. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
24 citing papers in PubMed, 123 citations in OpenAlex.
- Vitamin E supplementation increases circulating vitamin E metabolites tenfold in end-stage renal disease patients.Lipids · 2003Trial
- Urinary α-Carboxyethyl Hydroxychromanol (α-CEHC)-A Biomarker of Vitamin E Intake: A Scoping Review.The Journal of nutrition · 2026Article
- Human Vitamin E deficiency, and what is and is not Vitamin E?Free radical biology & medicine · 2024Review
- Strategies to Enhance the Solubility and Bioavailability of Tocotrienols Using Self-Emulsifying Drug Delivery System.Pharmaceuticals (Basel, Switzerland) · 2023Review
- Biomarker selection strategies based on compound stability in wastewater-based epidemiology.Environmental science and pollution research international · 2023Review
- Revisiting the therapeutic potential of tocotrienol.BioFactors (Oxford, England) · 2022Review
- Tocotrienol Supplementation Led to Higher Serum Levels of Lysophospholipids but Lower Acylcarnitines in Postmenopausal Women: A Randomized Double-Blinded Placebo-Controlled Clinical Trial.Frontiers in nutrition · 2021Article
- Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology.Proceedings of the National Academy of Sciences of the United States of America · 2019Article
- The Role of Tocotrienol in Protecting Against Metabolic Diseases.Molecules (Basel, Switzerland) · 2019Review
- Complexity of vitamin E metabolism.World journal of biological chemistry · 2016Review
- Drug Delivery Innovations for Enhancing the Anticancer Potential of Vitamin E Isoforms and Their Derivatives.BioMed research international · 2015Review
- α-Tocopherol does not accelerate depletion of γ-tocopherol and tocotrienol or excretion of their metabolites in rats.Lipids · 2013Article
- Urinary α-carboxyethyl hydroxychroman can be used as a predictor of α-tocopherol adequacy, as demonstrated in the Energetics Study.The American journal of clinical nutrition · 2012Article
- Article
- Alpha-tocotrienol is the most abundant tocotrienol isomer circulated in plasma and lipoproteins after postprandial tocotrienol-rich vitamin E supplementation.Nutrition journal · 2012Article
- Why tocotrienols work better: insights into the in vitro anti-cancer mechanism of vitamin E.Genes & nutrition · 2012Article
- Tocotrienols, the vitamin E of the 21st century: its potential against cancer and other chronic diseases.Biochemical pharmacology · 2010Review
- Optimization of the enzymatic hydrolysis and analysis of plasma conjugated gamma-CEHC and sulfated long-chain carboxychromanols, metabolites of vitamin E.Analytical biochemistry · 2009Article
- Gamma-tocotrienol and gamma-tocopherol are primarily metabolized to conjugated 2-(beta-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman and sulfated long-chain carboxychromanols in rats.The Journal of nutrition · 2009Article
- Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Limited information is available regarding metabolism of vitamin E forms, especially the tocotrienols. Carboxyethyl-hydroxychromans (alpha- and gamma-CEHC) are human urinary metabolites of alpha- and gamma-tocopherols, respectively. To evaluate whether tocotrienols are also metabolized and excreted as urinary CEHC, urine was monitored following tocotrienol supplementation. Complete (24 h) urine collections were obtained for 2 d prior to (baseline), the day of, and 2 d after human subjects (n = 6) ingested tocotrienol supplements. The subjects consumed 125 mg gamma-tocotrienyl acetate the first week, then the next week 500 mg; then 125 mg alpha-tocotrienyl acetate was administered the third week, followed by 500 mg the fourth week. Urinary alpha- and gamma-CEHC were measured by high-performance liquid chromatography with electrochemical detection. Urinary gamma-CEHC levels rose about four- to sixfold in response to the two doses of gamma-tocotrienol and then returned to baseline the following day. Significant (P < 0.0001) increases in urinary alpha-CEHC were observed only following ingestion of 500 mg alpha-tocotrienyl acetate. Typically, 1-2% of alpha-tocotrienyl acetates or 4-6% of gamma-tocotrienyl acetates were recovered as their respective urinary CEHC metabolites. A gamma-CEHC excretion time course showed an increase in urinary gamma-CEHC at 6 h and a peak at 9 h following ingestion of 125 mg gamma-tocotrienyl acetate. In summary, tocotrienols, like tocopherols, are metabolized to CEHC; however, the quantities excreted in human urine are small in relation to dose size.
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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.