α‐Tocopherol Supplementation Reduces γ‐Tocopherol‐ Dependent Scavenging Of Reactive Nitrogen Species By Decreasing γ‐Tocopherol

γ‐Tocopherol (γ‐T) has a unique function not shared by other vitamin E forms whereby it scavenges reactive nitrogen species (RNS) to form nitro‐γ‐tocopherol (NGT). Because α‐tocopherol (α‐T) supplementation decreases plasma γ‐T, we hypothesized that α‐T supplementation would also inhibit RNS scavenging by γ‐T. Smokers (n = 11) and nonsmokers (n = 10) were provided α‐tocopheryl acetate (150 mg/d) for 6 d and then plasma α‐T, γ‐T, and NGT were measured by LC‐MS on d −6, 0, 6, 13, and 17. Baseline α‐T and γ‐T did not differ between groups, but smokers’ NGT was greater than nonsmokers’ (57 ± 44 vs. 31 ± 10; P = 0.04). α‐T supplementation increased nonsmokers’ and smokers’ α‐T by 41–50%, but decreased γ‐T by 61–70% by d 0 with no differences between groups for either T. Ts were restored to baseline levels by d 6 in both groups. On d 0, smokers’ and nonsmokers’ NGT decreased by 72% and 50%, respectively, with no group differences and was restored to baseline levels by d 6. Timedependent changes in NGT were eliminated after its normalization to γ‐T (NGT/γ‐T), but plasma NGT was correlated ( P < 0.01) to γ‐T in nonsmokers (r = 0.41) and smokers (r = 0.55), supporting that γ‐T availability regulates NGT formation. Thus, α‐T supplementation may reduce the potential beneficial effects of γ‐T on RNS scavenging regardless of smoking status and improvements in γ‐T status may increase RNS scavenging capacity. Grant Funding Source : CT Department of Public Health and NIH DK59576