Clinical Trial on the Effects of Vitamin D Supplementation on Metabolic Profiles in Diabetic Hemodialysis

The current study was conducted to assess the effects of vitamin D supplementation on insulin metabolism, lipid fractions, biomarkers of inflammation, and oxidative stress in diabetic hemodialysis (HD) patients. This randomized double-blind placebo-controlled clinical trial was carried out among 60 diabetic HD patients. Subjects were randomly allocated into two groups to intake either oral vitamin D3 supplements at a dosage of 50 000 IU (n = 30) or placebo (n = 30) every 2 weeks for 12 weeks. After 12 weeks of intervention, subjects who received vitamin D supplements compared with the placebo had significantly decreased serum insulin concentrations (-3.4 +/- 3.7 vs. + 2.0 +/- 4.2 mu IU/ml, p < 0.001), homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (-1.2 +/- 1.8 vs. + 0.9 +/- 2.3, p < 0.001), and improved quantitative insulin sensitivity check index (QUICKI) (+ 0.02 +/- 0.03 vs. -0.01 +/- 0.02, p < 0.001). In addition, compared with the placebo, vitamin D supplementation led to significant reductions in serum high-sensitivity C-reactive protein (hs-CRP) (-1.4 +/- 2.5 vs. + 1.4 +/- 4.8 mg/l, p = 0.007), plasma malondialdehyde (MDA) (-0.1 +/- 0.2 vs. + 0.1 +/- 0.2 mu mol/l, p = 0.009) and a significant increase in plasma total antioxidant capacity (TAC) concentrations (+ 33.8 +/- 56.7 vs. -2.0 +/- 74.5 mmol/l, p = 0.04). We did not see any significant effect of vitamin D supplementation on lipid profiles and other biomarkers of inflammation and oxidative stress compared with the placebo. Overall, we found that vitamin D supplementation had beneficial effects on serum insulin, HOMA-IR, QUICKI, serum hs-CRP, plasma MDA, and TAC levels among diabetic HD patients for 12 weeks.