Format

Send to

Choose Destination
Am J Clin Nutr. 1995 Dec;62(6 Suppl):1527S-1534S. doi: 10.1093/ajcn/62.6.1527S.

Novel urinary metabolite of alpha-tocopherol, 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman, as an indicator of an adequate vitamin E supply?

Author information

1
Department of Vitamins and Atherosclerosis, German Institute of Human Nutrition, Potsdam-Rehbrücke, Germany.

Abstract

Previously, the metabolism of alpha-tocopherol was considered to involve the opening of the chroman structure because of its oxidation to tocopherylquinone. In contrast, we describe here 2,5,7,8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) as the major urinary metabolite of alpha-tocopherol that appears in human urine after vitamin E supplementation. It is formed directly from alpha-tocopherol without previous oxidative splitting of the chroman ring. The correlation of alpha-tocopherol intake, plasma alpha-tocopherol concentrations, and urinary excretion of alpha-CEHC in human volunteers supplemented with RRR-alpha-tocopherol dosages ranging from 0 to 800 mg/d was examined. HPLC and gas chromatography-mass spectroscopy analysis revealed that alpha-CEHC was only excreted when a plasma threshold of 7-9 mumol alpha-tocopherol/g total lipid was exceeded. This concentration was obtained by a daily intake of approximately 50-150 mg alpha-tocopherol. We suggest that alpha-CEHC excretion indicates a saturated binding capacity of vitamin E in the plasma and thus may be considered to be a marker of optimum vitamin E intake.

PMID:
7495255
DOI:
10.1093/ajcn/62.6.1527S
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center