Vitamin C to Pregnant Smokers Persistently Improves Infant Airway Function to 12â€…Months of Age: A Randomised Trial
grants from NHLBI R01HL105447, grants from NHLBI R01 HL105460, grants from Office of Dietary Supplements, grants from P51 OD011092565, grants from NIH UH3 OD023288, grants from UL1TR000128, during the conduct of the study.
European Respiratory Journal
Background Vitamin C (500 mg·day−1) supplementation for pregnant smokers has been reported to increase newborn pulmonary function and infant forced expiratory flows (FEFs) at 3 months of age. Its effect on airway function through 12 months of age has not been reported.
Objective To assess whether vitamin C supplementation to pregnant smokers is associated with a sustained increased airway function in their infants through 12 months of age.
Methods This is a prespecified secondary outcome of a randomised, double-blind, placebo-controlled trial that randomised 251 pregnant smokers between 13 and 23 weeks of gestation: 125 to 500 mg·day−1 vitamin C and 126 to placebo. Smoking cessation counselling was provided. FEFs performed at 3 and 12 months of age were analysed by repeated measures analysis of covariance.
Results FEFs were performed in 222 infants at 3 months and 202 infants at 12 months of age. The infants allocated to vitamin C had significantly increased FEFs over the first year of life compared to those allocated to placebo. The overall increased flows were: 40.2 mL·sec−1 for FEF75 (adjusted 95% CI for difference 6.6 to 73.8; p=0.025); 58.3 mL·sec−1 for FEF50 (95% CI 10.9 to 105.8; p=0.0081); and 55.1 mL·sec−1 for FEF25–75 (95% CI, 9.7 to 100.5; p=0.013).
Conclusions In offspring of pregnant smokers randomised to vitamin C versus placebo, vitamin C during pregnancy was associated with a small but significantly increased airway function at 3 and 12 months of age, suggesting a potential shift to a higher airway function trajectory curve. Continued follow-up is underway.
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McEvoy, C. T., Shorey-Kendrick, L. E., Milner, K., Schilling, D., Tiller, C., Vuylsteke, B., ... & Park, B. S. (2020). Vitamin C to Pregnant Smokers Persistently Improves Infant Airway Function to 12 Months of Age: A Randomised Trial. European Respiratory Journal.