The effects of vitamin D and probiotic co-supplementation on glucose homeostasis, inflammation, oxidative stress and pregnancy outcomes in gestational diabetes: A randomized, double-blind, placebo-controlled trial

Background and aims: This study was designed to assess the effects of combined vitamin D and probiotic supplementation on metabolic status and pregnancy outcomes in women with gestational diabetes (GDM). Methods: This randomized, double-blind, placebo-controlled clinical trial was performed in 87 women with GDM. Patients were randomly assigned three groups to receive either vitamin D (50,000 IU/every 2 weeks) plus probiotic (8 x 10(9) CFU/day) (n = 30), probiotic (8 x 10(9) CFU/day) (n = 29) or placebo (n = 28) for 6 weeks. Results: Vitamin D and probiotic co-supplementation significantly reduced fasting plasma glucose (beta -10.99 mg/dL; 95% CI, -14.26, -7.73; P < 0.001), serum insulin levels (beta -1.95 mu IU/mL; 95% CI, -3.05, -0.84; P = 0.001) and homeostasis model of assessment-insulin resistance (beta -0.76; 95% CI, -1.06, -0.45; P < 0.001), and significantly increased the quantitative insulin sensitivity check index (beta 0.01; 95% CI, 0.008, 0.03; P = 0.001) compared with the placebo. In addition, vitamin D and probiotic co-supplementation resulted in a significant reduction in triglycerides (beta -37.56 mg/dL; 95% CI, -51.55, -23.56; P < 0.001), VLDL- (beta -7.51 mg/dL; 95% CI, -10.31, -4.71; P < 0.001), HDL-/total cholesterol ratio (beta -0.52; 95% CI, -0.79, -0.24; P < 0.001), high sensitivity C-reactive protein (beta -1.80 mg/L; 95% CI, -2.53, -1.08; P < 0.001) and malondialdehyde (beta -0.43 pmol/L; 95% CI, -0.77, -0.09; P = 0.01); also, a significant rise in HDL-cholesterol (beta 4.09 mg/dL; 95% CI, 1.11, 7.08; P = 0.008) and total antioxidant capacity (TAC) levels (beta 97.77 mmol/L; 95% CI, 52.34,143.19; P < 0.001) were observed compared with the placebo. Vitamin D and probiotic co-supplementation did not change other metabolic parameters. Vitamin D and probiotic co-supplementation significantly decreased triglycerides (P = 0.02), VLDL-cholesterol (P = 0.02) and hs-CRP (P = 0.01), and significantly increased TAC (P = 0.006) and total glutathione levels (P = 0.04) compared with only probiotic group. Conclusions: In conclusion, vitamin D and probiotic co-supplementation in women with GDM had beneficial effects on metabolic status. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.