This Kinetic, Bioavailability, and Metabolism Study of RRR-alpha-Tocopherol in Healthy Adults Suggests Lower Intake Requirements than Previous Estimates

submitted by: jnusda
Kinetic models enable nutrient needs and kinetic behaviors to be quantified and provide mechanistic insights into metabolism. Therefore, we modeled and quantified the kinetics, bioavailability, and metabolism of RRR-alpha-tocopherol in 12 healthy adults. Six men and 6 women, aged 27 +/- 6 y, each ingested 1.81 nmol of 14C-RRR-alpha-tocopherol; each dose had 3.70 kBq of 14C. Complete collections of urine and feces were made over the first 21d from dosing. Serial blood samples were drawn over...
Authors: Janet Novotny, James Fadel, Dirk Holstege, Harold Furr, Andrew Clifford

Urinary a-carboxyethyl hydroxychroman can be used as a predictor of a-tocopherol adequacy, as demonstrated in the Energetics Study

submitted by: mtraber
Background: Other than the in vitro erythrocyte hemolysis test, no valid biomarkers of vitamin E status currently exist. Objective: We hypothesized that the urinary vitamin E metabolite a-carboxyethyl hydroxychroman (a-CEHC) could serve as a biomarker. Design: The relations between urinary a-CEHC, plasma a-tocopherol, and vitamin E intakes were assessed by using a previously validated multipass, Web-based, 24-h self-administered dietary recall, and we concurrently collected plasma and...
Authors: Katie M Lebold, Alfonso Ang, Maret G Traber, Lenore Arab