Vitamin E supplementation increases circulating vitamin E metabolites tenfold in end-stage renal disease patients.
Vitamin E supplementation could elevate circulating vitamin E metabolites while modulating oxidative and inflammatory status in end-stage renal failure patients undergoing hemodialysis. Plasma concentrations of carboxyethyl-hydroxychromanols (alpha- and gamma-CEHC), ascorbic acid, alpha- and gamma-tocopherols, F2-isoprostanes, and inflammatory biomarkers [tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), ferritin, and C-reactive protein (CRP)] were measured in blood samples obtained from patients (n = 11) before and after dialysis on two occasions prior to, and at 1 and 2 mon of daily vitamin E supplementation (400 IU RRR-alpha-tocopherol). Supplementation nearly doubled plasma alpha-tocopherol concentrations (from 18 +/- 0.5 to 31 +/- 1.7 microM, P < 0.0001), whereas gamma-tocopherol concentrations decreased (from 2.8 +/- 0.3 to 1.7 +/- 0.2 microM, P = 0.001). Serum alpha-CEHC increased 10-fold from 68 +/- 3 to 771 +/- 175 nM (P < 0.0001), and gamma-CEHC increased from 837 +/- 164 to 1136 +/- 230 nM (P = 0.008). Vitamin E supplementation also increased postdialysis hematocrits from 38 +/- 1% to 41 +/- 1% (P < 0.001). Dietary antioxidant intakes (vitamins E and C) were low in most subjects; plasma ascorbic acid levels (88 +/- 27 microM) decreased significantly with dialysis (33 +/- 11 microM, P = 0.01). Plasma IL-6, CRP, TNF-alpha, and free F2-isoprostane concentrations were elevated throughout the study. There is a complex relationship between chronic inflammation and oxidative stress that is not mitigated by short-term vitamin E supplementation. Importantly, serum vitamin E metabolite concentrations that increased 10-fold within 30 d of supplementation did not increase further, suggesting routes other than urine for removal of metabolites.
Department of Nutrition and Food Management, Oregon State University, Corvallis, Oregon 97331, USA.
Kylie Sherée
KS
Smith
Chia-Lin
CL
Lee
James W
JW
Ridlington
Scott W
SW
Leonard
Sridevi
S
Devaraj
Maret G
MG
Traber
D000368:Aged; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D001205:Ascorbic Acid / Q000097:blood / Q000378:metabolism / Q000494:pharmacology; D001682:Biological Availability; D002097:C-Reactive Protein / Q000032:analysis; D019587:Dietary Supplements; D004921:Erythropoietin / Q000494:pharmacology; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007501:Iron / Q000097:blood; D007676:Kidney Failure, Chronic / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012995:Solubility; D014810:Vitamin E / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology*
D000975:Antioxidants; D004921:Erythropoietin; D014810:Vitamin E; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron; D001205:Ascorbic Acid