Supplementation with antioxidant micronutrients in pregnant women with obesity: a randomized controlled trial

Background/Objective: Obesity increases maternal morbidity and adversely affects child health. Maternal inflammation may play a role in adverse outcomes. The objective of this study was to determine whether providing a higher dose of antioxidant micronutrients to pregnant women with obesity would raise concentrations of key antioxidant vitamins and impact inflammation and oxidative stress during pregnancy. Subjects/Methods: This was a double-blind, randomized controlled trial. We recruited pregnant women with a body mass index (BMI) >= 30 kg/m(2) at their initial prenatal visit ( < 13 weeks gestation) and collected blood and urine samples at baseline, 24-28 weeks, and 32-36 weeks to measure micronutrient concentrations (vitamin C, E, B-6 and folate), markers of inflammation (C-reactive protein, interleukin-6, 8, and 1 beta) and oxidative stress (8-epi-PGF2 alpha and malondialdehyde). We collected maternal and infant health data from enrollment to delivery as secondary outcomes. We enrolled 128 participants (64 in each arm), and 98 (49 in each arm) completed follow-up through delivery. Intervention: Both groups received a standard prenatal vitamin containing the recommended daily allowance of micronutrients in pregnancy. In addition, the intervention group received a supplement with 90 mg vitamin C, 30 alpha TU vitamin E, 18 mg vitamin B6, and 800 mu g folic acid, and the control group received a placebo. Results: The intervention group had higher vit B-6 (log transformed (ln), beta 24-28 weeks: 0.76 nmol/L (95% CI: 0.40, 1.12); beta 32-36 weeks: 0.52 nmol/L (95% CI: 0.17, 0.88)) than the control group. Vitamins C, E, erythrocyte RBC folate concentrations did not differ by randomization group. The intervention did not impact biomarkers of inflammation or oxidative stress. There were no differences in maternal or neonatal clinical outcomes by randomization group. Conclusions: Higher concentrations of antioxidant vitamins during pregnancy increased specific micronutrients and did not impact maternal inflammation and oxidative stress, which may be related to dosing or type of supplementation provided.