The effects of vitamin D and omega-3 fatty acids co-supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in patients with gestational diabetes

Randomized, double-blind, placebo-controlled trial of 120 pregnant women with gestational diabetes mellitus (GDM), aged 18–40 years, at 24–28 weeks’ gestation.

Four regimens over 6 weeks: (1) Omega-3 fatty acids 1000 mg per dose (180 mg EPA + 120 mg DHA) twice daily + vitamin D placebo; (2) Vitamin D 50,000 IU every 2 weeks + omega-3 fatty acids placebo; (3) Vitamin D 50,000 IU every 2 weeks + omega-3 fatty acids 1000 mg twice daily; (4) Vitamin D placebo + omega-3 fatty acids placebo.

Co-supplementation with vitamin D and omega-3 fatty acids for 6 weeks reduced inflammatory and oxidative stress biomarkers and improved some neonatal outcomes in GDM. Specifically, hs-CRP decreased by 2.0 mg/L (vs −0.8 to −1.3 and +0.9 mg/L in comparison groups, P = 0.008); MDA decreased by 0.5 μmol/L (vs −0.2, −0.3 and +0.5, P < 0.001); TAC increased by 92.1 mmol/L (vs 55.1, 88.4 and 1.0, P = 0.001); GSH increased by 75.9 μmol/L (vs 23.0, 30.0 and −7.8, P = 0.001). Newborn hyperbilirubinemia (10.0% vs 40.0%, P = 0.037) and newborn hospitalization (10.0% vs 40.0%, P = 0.037) were lower in the co-supplemented group. No significant effect on plasma NO or other pregnancy outcomes. This suggests a synergistic benefit of combining vitamin D with omega-3 fatty acids in GDM.

Lack of measurements of circulating EPA, DHA and other omega-3 fatty acids at baseline and after the 6-week intervention due to budget limitations.