HyperhomocysteinemiaVitamin B 12Folic AcidHomocystineCystathionine beta-SynthaseMethylenetetrahydrofolate Reductase (NADPH2)MethionineVitamin B ComplexVitamin B 6Betaine-Homocysteine S-MethyltransferaseCystathionine5-Methyltetrahydrofolate-Homocysteine S-MethyltransferaseS-AdenosylhomocysteineHomocystinuriaOxidoreductases Acting on CH-NH Group DonorsVitamin B 12 DeficiencyFolic Acid DeficiencyMethylmalonic AcidBetaineS-AdenosylmethionineHomocysteine S-MethyltransferasePyridoxine5,10-Methylenetetrahydrofolate Reductase (FADH2)Glycine N-MethyltransferaseRisk FactorsCysteineDietary SupplementsTetrahydrofolatesAdenosylhomocysteinaseVitamin B DeficiencyTranscobalaminsVitamin B 6 DeficiencyBiological MarkersMethylationGenotypeSarcosineCystathionine gamma-LyasePolymorphism, GeneticCardiovascular DiseasesPyridoxal PhosphateLipotropic AgentsCase-Control StudiesDietVascular DiseasesMethyltransferasesCysteic AcidFastingMethylenetetrahydrofolate Dehydrogenase (NAD+)Molecular Sequence DataEndothelium, VascularPhosphatidylethanolamine N-MethyltransferaseCells, CulturedFluorescence Polarization ImmunoassaySulfhydryl CompoundsReference ValuesCholineRNA, MessengerTime FactorsFerredoxin-NADP ReductaseNeural Tube DefectsDose-Response Relationship, DrugRiboflavinVitaminsNutritional StatusAmino Acids, SulfurSulfurFood, FortifiedLiverBase SequenceArteriosclerosisMutationCreatinineTubercidinChromatography, High Pressure LiquidDipeptidesCross-Sectional StudiesHematinicsProspective StudiesCopper SulfateMethionine-tRNA LigaseOxidative StressAnalysis of VarianceHomozygoteGuanidinoacetate N-MethyltransferaseDouble-Blind MethodGlutathioneMethylenetetrahydrofolate Dehydrogenase (NADP)Regression AnalysisNicotinamide N-MethyltransferaseLipoprotein(a)C-Reactive ProteinCoffeeLipidsCell LineKineticsErythrocytesAmino Acid SequenceAgingCohort StudiesCholine Deficiency