The decrease in gamma-tocopherol in plasma and lipoprotein fractions levels off within two days of vitamin E supplementation.
The effects of vitamin E supplementation on alpha- and gamma-tocopherol concentrations were studied in plasma and lipoprotein fractions of five healthy volunteers taking 1000 IU/day of RRR alpha-tocopherol for 4 days. Although plasma alpha-tocopherol increased, gamma-tocopherol decreased. Compared with baseline, gamma-/alpha-tocopherol ratios decreased from 48 h onward (P < 0.001). They all leveled off within 48 h. From 12 h onward, gamma-/alpha-tocopherol ratios were higher in VLDL and IDL than in LDL and HDL, indicating that gamma-tocopherol is better maintained in triglyceride-rich lipoprotein fractions. These data suggest that vitamin E supplementation exceeding 2 days does not further decrease gamma-tocopherol concentrations.
Sundl
Isabella
I
Human Nutrition & Metabolism Research and Training Center, Institute of Molecular Biosciences, Karl-Franzens University, Schubertstrasse 1, A-8010 Graz, Austria.
Resch
Ulrike
U
Bergmann
Andreas R
AR
Roob
Johannes M
JM
Winklhofer-Roob
Brigitte M
BM
D000328:Adult; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007700:Kinetics; D008074:Lipoproteins / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage*; D024502:alpha-Tocopherol / Q000097:blood; D024504:gamma-Tocopherol / Q000097:blood*
D008074:Lipoproteins; D008075:Lipoproteins, HDL; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014810:Vitamin E; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol