Babies of women who smoke during pregnancy had significantly improved lung function at birth if their mother took Vitamin C, according to research presented at the Pediatric Academic Societies (PAS) annual meeting in Washington, DC. Researchers believe the supplement have great public health significance to block some effects of in-utero smoke on lung development.

For the study, investigators randomly assigned smokers who were less than 22 weeks pregnant to either one 500 milligram capsule of vitamin C or a placebo each day with a prenatal vitamin.

Two days after birth, researchers tested how the newborn breathed in and out, how easily the baby’s lungs moved and how big the baby’s lungs were. Those born to women who took vitamin C had significantly improved lung function compared with those whose mothers took a placebo. During the child’s first year of life, infants whose mothers were in the vitamin C group had significantly less wheezing than the placebo group.

When analyzing the effect of maternal ?5 nicotinic receptor genotype, researchers discovered that “infants of pregnant smokers homozygous or heterozygous for the rs16969968 risk allele and randomized to vitamin C had a significantly decreased incidence of wheezing compared to those randomized to placebo.”

“Though the lung function of all babies born to smokers in our study was improved by supplemental vitamin C,” said lead author Cynthia T. McEvoy, MD, MCR, FAAP, associate professor of pediatrics at Oregon Health & Science University (OHSU) Doernbecher Children’s Hospital. “Our preliminary data suggest that vitamin C appeared to help those babies at the greatest risk of harm during their development from their mother’s smoking in pregnancy.”