Nutritional Epigenetics of Vitamin Intake (A, B₁, B₂, B₃, B₆, B₁₂, and E): Associations with Genome-Wide DNA...

DNA methylation is a key epigenetic mechanism involved in gene regulation and chromatin stability and may be influenced by nutritional exposures. However, population-level evidence regarding associations between dietary vitamin intake and genome-wide DNA methylation remains limited.

We investigated associations between dietary intake of vitamins A, B₁, B₂, B₃, B_6, B₁₂, and E and blood DNA methylation in 2030 participants from the Southern Community Cohort Study (SCCS). Dietary intake was assessed using a validated Food Frequency Questionnaire, and genome-wide DNA methylation was profiled using the Illumina Infinium MethylationEPIC v2.0 BeadChip. Epigenome-wide association analyses were conducted using robust linear regression models adjusted for demographic, lifestyle, and estimated cellular composition variables.

We identified 34 CpG sites associated with dietary intake of vitamins B₁, B₂, B₃, B₆, and E, at a false discovery rate-adjusted p-value (FDR_p) threshold of <0.1. The strongest association was observed between vitamin B₆ intake and cg19831775 (Beta = -0.111, FDR_p = 0.015). No statistically significant associations were identified for vitamins A and B₁₂. Most observed effects were modest, and associations were locus-specific rather than global. Race- and sex-stratified analyses demonstrated generally consistent directions of association, although statistical significance was attenuated in subgroup analyses.

These findings provide suggestive evidence that dietary intake of vitamins B_1, B₂, B₃, B₆ and E may be associated with subtle variation in DNA methylation at specific genomic loci.