Effect of vitamin C supplementation on oxidative stress and lipid profiles in hemodialysis patients.
OBJECTIVE
The increase in oxidative stress is the main factor in acceleration of atherosclerosis, leading to death in hemodialysis patients. Vitamin C is one of the most important antioxidants that inhibits lipid peroxidation and improves endothelial function. This study aims to assess the effects of vitamin C supplementation on lipid profiles as well as markers of lipid peroxidation among hemodialysis patients.


METHODS
In this double-blind, randomized, controlled clinical trial, a total of 42 patients were randomly assigned to vitamin C (n=21) or placebo groups (n=21). Patients in the vitamin C group consumed 250 mg vitamin C and those in the placebo group were given placebo every other day for 12 weeks. Fasting blood samples were collected at baseline and at the end of the study to measure serum concentrations of lipid profiles, as well as malondialdehyde (MDA) and vitamin C.


RESULTS
After supplementation with vitamin C, serum vitamin C levels increased significantly in the vitamin C group as compared to baseline (p=0.033). There was also a significant difference in serum vitamin C levels between vitamin C and placebo groups (p=0.001). Serum MDA concentrations were marginally decreased in the vitamin C group after taking supplements (p=0.057). A significant difference was also seen in mean MDA changes between vitamin C and placebo groups (p=0.002). There was a significant difference in serum levels of total cholesterol (p=0.005), low-density lipoprotein (LDL-C) (p=0.012), and LDL-C/high-density lipoprotein (HDL-C) ratio (p=0.018) between the two groups; however, serum triglyceride and HDL-C levels were not significantly different between groups.


CONCLUSIONS
Every other day supplementation with 250 mg vitamin C for 12 weeks increases serum vitamin C, decreases MDA levels, and improves lipid profiles in hemodialysis patients.
School of Health, Zabol University of Medical Sciences, Tehran, Iran.
Hadi
H
Abdollahzad
Shahriar
S
Eghtesadi
Issa
I
Nourmohammadi
Mohammadhasan
M
Khadem-Ansari
Hossein
H
Nejad-Gashti
Ahmad
A
Esmaillzadeh
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000008:administration & dosage* / Q000032:analysis; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D002784:Cholesterol / Q000097:blood; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D006435:Renal Dialysis / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
D000975:Antioxidants; D014280:Triglycerides; D008315:Malondialdehyde; D002784:Cholesterol; D001205:Ascorbic Acid