The association between first trimester micronutrient intake, MTHFR genotypes, and global DNA methylation in pregnant women

OBJECTIVE: Our aim was to evaluate possible associations between consumption of micronutrients involved in one-carbon metabolism, MTHFR genotypes, and global DNA methylation in pregnant women. METHODS: A semi-quantitative dietary questionnaire was administered to 195 women during their first trimester in Morelos, Mexico. Two functional polymorphisms of the key folate-metabolizing gene, i.e. MTHFR 677 C>T and 1298 A>C, as well as global DNA methylation were assessed in peripheral blood drawn during the interview. RESULTS: Independent of maternal age and caloric intake, vitamin B(6) deficiency was associated with 1.8 fold increased risk of hypomethylation in women carrying the MTHFR 677 T allele. CONCLUSIONS: There exists a subpopulation that is more susceptible to B vitamin deficiencies.