Vitamin E kinetics in smokers and nonsmokers.
Does cigarette smoking increase vitamin E utilization in vivo? A trial was carried out in 6 smokers and 5 nonsmokers of comparable ages and serum lipids. Subjects consumed 75 mg each d(3)-RRR and d(6)-all rac-alpha-tocopheryl acetates (natural and synthetic vitamin E, respectively) daily for 7 d with a standardized breakfast. Fasting blood samples were drawn on days -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 14, 21 (negative days indicate supplementation). In both groups, plasma d(3)-alpha-tocopherol concentrations were approximately double of d(6)-alpha-tocopherol. At day 0, the %d(3) alpha-tocopherols (d(3)-alpha-tocopherol/total-alpha-tocopherol x 100) were similar in both smokers and nonsmokers. Subsequently, there was a trend toward a faster exponential disappearance of the plasma %d(3) alpha-tocopherol in smokers compared with nonsmokers (0.30 +/- 0.04 compared with 0.24 +/- 0.05, p =.0565). The calculated %d(3) half-lives were 55.6 +/- 7.4 h in smokers and 72.1 +/- 17.3 h in nonsmokers (p =.0630). By day 21, the %d(3) in smokers had decreased to 1.4% +/- 0.3% while it was 2.2% +/- 0.7% (p =.0418) in the nonsmokers. These data suggest that smoking increases plasma vitamin E disappearance, but further studies are needed to confirm this finding and to assess its cause.
Traber
M G
MG
Department of Internal Medicine, University of California, Davis, School of Medicine, Sacramento, CA, USA. maret.traber@orst.edu
Winklhofer-Roob
B M
BM
Roob
J M
JM
Khoschsorur
G
G
Aigner
R
R
Cross
C
C
Ramakrishnan
R
R
Brigelius-Flohé
R
R
D000328:Adult; D002784:Cholesterol / Q000097:blood; D003903:Deuterium; D006801:Humans; D007700:Kinetics; D008315:Malondialdehyde / Q000097:blood; D012907:Smoking / Q000097:blood*; D024505:Tocopherols; D014280:Triglycerides / Q000097:blood; D014810:Vitamin E / Q000493:pharmacokinetics*; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics
D014280:Triglycerides; D014810:Vitamin E; D008315:Malondialdehyde; D002784:Cholesterol; D003903:Deuterium; D024502:alpha-Tocopherol; D024505:Tocopherols