The Decrease in ?-Tocopherol in Plasma and Lipoprotein Fractions Levels Off within Two Days of Vitamin E Supplementation
The effects of vitamin E supplementation on ?- and ?-tocopherol concentrations were studied in plasma and lipoprotein fractions of five healthy volunteers taking 1000 IU/day of RRR ?-tocopherol for 4 days. Although plasma ?-tocopherol increased, ?-tocopherol decreased. Compared with baseline, ?-/?-tocopherol ratios decreased from 48 h onward (P < 0.001). They all leveled off within 48 h. From 12 h onward, ?-/?-tocopherol ratios were higher in VLDL and IDL than in LDL and HDL, indicating that ?-tocopherol is better maintained in triglyceride-rich lipoprotein fractions. These data suggest that vitamin E supplementation exceeding 2 days does not further decrease ?-tocopherol concentrations.
?-tocopherol ?-tocopherol plasma lipoproteins vitamin e supplementation ?-/?-tocopherol ratio vldl ldl idl hdl