Human plasma and tissue alpha-tocopherol concentrations in response to supplementation with deuterated natural and synthetic vitamin E.
We report a comparison of natural and synthetic vitamin E in humans using deuterium labeling to permit the two forms of vitamin E to be measured independently in plasma and tissues of each subject. Differences in natural and synthetic vitamin E concentrations were measured directly under equal dosage conditions using an equimolar mixture of deuterated RRR-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate. Two groups of five adults took 30 mg of the mixture as a single dose and as eight consecutive daily doses, respectively. After a 1-mo interval the schedule was repeated but with a 10-fold higher dose (ie, 300 mg). In each case, the ratio of plasma d3-RRR-alpha-tocopherol to d6-all-rac-alpha-tocopherol (RRR:rac) increased from approximately 1.5-1.8 to approximately 2 after dosing ended. In an elective surgery study in which 22 patients were given 150 mg/d for up to 41 d before surgery, the RRR:rac in tissues was lower than in plasma and the percentage of deuterated alpha-tocopherol was lower in all tissues except gallbladder and liver. In a terminally ill patient given 30 mg/d for 361 d, plasma and tissue (x+/-SD) RRR-rac ratios (and % deuterated alpha-tocopherol) at autopsy were 2.06 (6.3%) and 1.71+/-0.24 (5.9+/-2.2%), respectively. In a second terminally ill patient given 300 mg/d for 615 d, the corresponding values were 2.11 (68%) and 2.01+/-0.17 (65+/-10%), respectively. The results indicated that natural vitamin E has roughly twice the availability of synthetic vitamin E. This 2:1 ratio is significantly higher than the currently accepted RRR:rac of 1.36:1.00. Gamma-Tocopherol, expressed as a fraction of total unlabeled tocopherols in 15 elective surgery patients, was 1.4-4.6 (mean: 2.6) times greater in adipose tissue, muscle, skin, and vein than in plasma, which is a substantially larger fraction than had been recognized previously.[1]References
- Human plasma and tissue alpha-tocopherol concentrations in response to supplementation with deuterated natural and synthetic vitamin E. Burton, G.W., Traber, M.G., Acuff, R.V., Walters, D.N., Kayden, H., Hughes, L., Ingold, K.U. Am. J. Clin. Nutr. (1998) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
