Improvements in lung function following vitamin C supplementation to pregnant smokers are associated with buccal DNA methylation at 5 years of age

This epigenome-wide association study examined the relationship between buccal cell DNA methylation and improvements in lung function in 158 children born to cigarette-smoking mothers who received vitamin C supplementation or placebo during pregnancy. Lung function testing (FEV1, FVC, FEV1/FVC ratio, FEF25–75) was undertaken when the children were aged 5 years using a Vitalograph Pneumotrac spirometer.