(P11-056-23) Association of Vitamin B12 and DNA Methylation Among Mother-Child Pairs in Bangladesh

Objectives: Adequate maternal vitamin B12 (B12) status during pregnancy is essential for synthesis of methyl groups for CpG (cytosine-guanine) methylation and epigenetic regulation. However, little is known how B12 status influences genome-wide DNA methylation levels in mothers during pregnancy and infants. We aimed to evaluate the association between vitamin B12 and genome-wide methylation among mother-infant pairs.

Methods: In a blinded, placebo-controlled trial; Bangladeshi women (18-35 years, hemoglobin < 110g/L) were randomized to receive either 250micrgram/day B12 or placebo throughout pregnancy up to 3-mo postpartum. Blood was collected from mothers at the beginning of pregnancy (gestational weeks 11–14) and 3-month postpartum, and infants at 3-months. Concentration of vitamin B12 was measured in plasma. Genome-wide DNA methylation was measured in DNA from peripheral blood mononuclear cells using Infinium Methylation EPIC BeadChip (Illumina).

Results: Maternal B12 (n=19) at 3-month postpartum was related to fraction of maternal DNA methylation 3-month postpartum, of which most prominent was the CpG site cg08749286 in MCPH (microcephalin, expressed during fetal brain development) (linear regression analysis, p=0.054). Principal component analysis (PCA) suggested an association between maternal B12 in early pregnancy and DNA methylation of the 3-months old infants.

Conclusions: Our data suggest that maternal B12 status is associated with maternal and infant DNA methylation.

Funding Sources: Nestle Foundation and Swedish International Development Cooperation Agency