Effects of mixed tocopherol versus alpha-tocopherol supplementation on tocopherol concentrations in plasma and buccal mucosal cells

Background: Little is know about the effects of supplementation with different forms of vitamin E (alpha-, beta-, gamma-, delta-tocopherol; AT, BT, GT, DT) on plasma and buccal mucosal cell (BMC) concentrations. The aim of this randomized double-blind placebo-controlled study was to compare the effects of supplementation with mixed tocopherols (MT; containing 60% GT, 24% DT, 14% AT, and 2% BT) and AT alone on vitamin E concentrations in plasma and BMC. Methods: Healthy male subjects, n=81, 18–45yrs, were randomly assigned to take increasing doses (36.8, 73.5, 147 or 294mg/d) of MT or 294mg/d AT or placebo for 4 weeks. Vitamin E concentrations were determined before and after supplementation in plasma and in BMC using HPLC. Results: (1) AT group: In BMC, AT concentrations increased 1.5-fold (P<0.001), while GT decreased 4-fold (P<0.001) and DT did not change. (2) MT groups: BMC GT concentrations increased 1.3 to 2-fold in the 73.5, 147 and 294mg/d MT groups ( P =0.03, P <0.001, P =0.002, respectively), while BMC AT and DT increased only in the 147mg MT group ( P =0.006, P =0.02, respectively). Similar results were found for plasma concentrations of AT, GT and DT. There were no changes in the placebo group. BMC concentrations correlated significantly with plasma concentrations both before and after supplementation (all supplementation groups combined): AT (before, r =0.23, P =0.04; after, r =0.26, P =0.02) and GT (before, r =0.51, P <0.001; after, r =0.71, P <0.001). DT correlated only after supplementation ( r =0.36, P <0.001). Conclusions: This is the first study showing BMC and plasma concentrations of AT, GT and DT in response to MT as compared to AT supplementation. Because of increasing evidence of health promoting effects of GT, depletion of GT at the cellular level as a consequence of AT supplementation should be avoided.