Prenatal vitamin intake in first month of pregnancy and DNA methylation in cord blood and placenta in two prospective cohorts.

"code files are available through github ( https://github com/bakulskilab )."

"Declarations Ethics approval and consent to participateThe EARLI study was reviewed and approved by Human Subjects Institutional Review Boards (IRBs) from each of the four study sites (Johns Hopkins University, Drexel University, University of California Davis, and Kaiser Permanente Northern California). The MARBLES protocol was reviewed and approved by the Human Subjects IRB from University of California Davis. The University of Michigan Institutional Review Board (HUM00116291) approved these secondary data analyses. Consent for publicationAll co-authors read and approved the final manuscript. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding Nutrient and DNA methylation measures and analyses were supported by the National Institutes of Health (R01 ES025574, PI: Schmidt). Cord blood DNA methylation was also funded by R01 ES025531, PI: Fallin. Funding for the EARLI study was provided by the National Institutes of Health (R01ES016443, PI: Newschaffer) and Autism Speaks (003953 PI: Newschaffer). The MARBLES study was funded by National Institutes of Health grants (R24ES028533, R01ES020392, R01ES028089, R01ES020392, P01ES011269) and an EPA STAR grant (#RD-83329201). Support for this research was also provided by the National Institutes of Health grants (P30 ES017885 and R24 ES030893, PI: Fallin). Mr. Dou and Dr. Bakulski were also supported by grants (R01 ES025531, PI: Fallin; R01 AG067592, MPI: Bakulski; R01 MD013299). Dr. Zhu and Dr. LaSalle were supported by R01 ES029213. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health."