PLASMA RRR-ALPHA-TOCOPHEROL CONCENTRATIONS ARE LOWER IN SMOKERS THAN IN NONSMOKERS AFTER INGESTION OF A SIMILAR ORAL LOAD OF THIS ANTIOXIDANT VITAMIN

1. Using deuterium-labelled alpha-tocopherol (vitamin E), the plasma k inetics of alpha-tocopherol derived from supplemental RRR-alpha-tocoph erol and RRR-alpha-tocopheryl acetate were determined in asymptomatic individuals who smoke and, for comparison, in a group of healthy non-s mokers, 2. Venous blood samples were withdrawn 6, 12 and 27 h after th e oral administration of a gelatin capsule containing an equimolar mix ture of RRR-alpha-tocopherol and RRR-alpha-tocopheryl acetate, Plasma concentrations of endogenous and administered forms of alpha-tocophero l were determined by a combination of HPLC and GC-MS. 3. Both the free phenol and the acetate ester concentrations of alpha-tocopherol were lower in smokers than in non-smokers: 0.99 versus 1.60 (P < 0.05) and 0.66 versus 1.49 (P < 0.05) mu mol/mmol cholesterol for RRR-alpha-toco pherol and RRR-alpha-tocopheryl acetate respectively, The highest conc entration of alpha-tocopherol derived from administered RRR-alpha-toco pherol and its acetate ester were observed in plasma at 12 h (compared with 6-h and 27-h measurements) in most subjects, 4. Although the two forms of alpha-tocopherol were administered in equal doses, plasma fr om smokers contained significantly higher concentrations of RRR-alpha- tocopherol derived from the free phenol form than from the acetate for m (0.99 versus 0.66 mu mol/mmol cholesterol, P < 0.05, 12 h), Nonsmoke rs did not exhibit preferential uptake of either form of vitamin E, 5. These results suggest that individuals who smoke have either a reduce d ability to absorb alpha-tocopherol, particularly when it is presente d as the acetate ester, or increased clearance of newly absorbed alpha -tocopherol compared with non-smokers.