MethionineHyperhomocysteinemiaVitamin B 12Folic Acid5-Methyltetrahydrofolate-Homocysteine S-MethyltransferaseMethionine Sulfoxide ReductasesCystathionine beta-SynthaseHomocystineMethionine AdenosyltransferaseMethylenetetrahydrofolate Reductase (NADPH2)CystathionineS-AdenosylmethionineBetaine-Homocysteine S-MethyltransferaseVitamin B 6Vitamin B ComplexS-AdenosylhomocysteineHomocystinuriaOxidoreductases Acting on CH-NH Group DonorsVitamin B 12 DeficiencyFolic Acid DeficiencyBetaineCysteineMethionyl AminopeptidasesAmino Acids, SulfurGlycine N-MethyltransferaseMethylmalonic AcidTetrahydrofolatesHomocysteine S-MethyltransferasePyridoxineHomocysteineMethylation5,10-Methylenetetrahydrofolate Reductase (FADH2)Amino AcidsDietary SupplementsMethionine-tRNA LigaseSulfurAdenosylhomocysteinaseMethyltransferasesCystathionine gamma-LyaseCystineEthionineVitamin B DeficiencyDietTranscobalaminsVitamin B 6 DeficiencyMethionine SulfoximineSarcosineRisk FactorsFerredoxin-NADP ReductaseCholineEnkephalin, MethionineLipotropic AgentsOxidation-ReductionAminopeptidasesLiverSulfur RadioisotopesMolecular Sequence DataVitamin UAmino Acid SequenceGenotypeSulfhydryl CompoundsCholine DeficiencyPyridoxal PhosphateKineticsPolymorphism, GeneticThionucleosidesCysteic AcidBiological MarkersPhosphatidylethanolamine N-MethyltransferaseMutationEscherichia coliGlutathioneCarbon-Oxygen LyasesChromatography, High Pressure LiquidOxidoreductasesMethylenetetrahydrofolate Dehydrogenase (NAD+)Food, FortifiedCardiovascular DiseasesNeural Tube DefectsCase-Control StudiesFastingVascular DiseasesSulfur CompoundsLyasesRiboflavinBase SequenceDose-Response Relationship, DrugCysteine SynthaseEndothelium, VascularIsoleucineOxidative StressNutritional RequirementsCarbon-Sulfur LyasesMethylenetetrahydrofolate Dehydrogenase (NADP)NorleucineGlycineSulfur IsotopesCarbon IsotopesHomoserineVitamins