Fig. 1From: The effects of long-term daily folic acid and vitamin B12 supplementation on genome-wide DNA methylation in elderly subjectsFlow diagram for the selection of participants and the analysis of samples. aSelf-reported change in use of dietary supplements containing folic acid or vitamin B12. bSerum levels of folate or vitamin B12 and plasma levels of homocysteine. Abbreviations: CRP C-reactive protein, MTHFR methylenetetrahydrofolate reductase, SNP single nucleotide polymorphism, SWAN subset-quantile within array normalizationBack to article page