Richmond RC, et al. - Researchers carried out an epigenome-wide association study (EWAS) nested within the Aberdeen Folic Acid Supplementation Trial (AFAST—a trial of two different doses: 0.2 and 5 mg, folic acid vs placebo) to better elucidate the long-term impact of maternal folic acid in pregnancy on DNA methylation in offspring. They recognized an association between maternal folic-acid supplement use and changes in the DNA methylation of the offspring that persisted for many years after exposure in utero. These methylation changes were observed to be located in genes implicated in embryonic development, immune response and cellular proliferation.