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 lipi ds. Subjects consumed 75 mg each d(3)-RRR and d(6)-all rac-alpha -tocophery l acetates (natural and synthetic vitamin E, respectively) daily for 7 d wi th 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 ind icate supplementation). In both groups, plasma d(3)-alpha -tocopherol conce ntrations were approximately double of d(6)-alpha -tocopherol. At day 0, th e %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) alph a -tocopherol in smokers compared with nonsmokers (0.30 +/- 0.04 compared w ith 0.24 +/-0.05, p =.0565). The calculated %d(3) half-lives were 55.6 +/- 7.4 h in smokers and 72.1 +/- 7.3 h in nonsmokers (P =.0630). By day 21, th e %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 p lasma vitamin E disappearance, but further studies are needed to confirm th is finding and to assess its cause. (C) 2001 Elsevier Science Inc.