Methylenetetrahydrofolate Reductase (NADPH2)5,10-Methylenetetrahydrofolate Reductase (FADH2)Oxidoreductases Acting on CH-NH Group DonorsMethylenetetrahydrofolate Dehydrogenase (NADP)HomocysteineMethylenetetrahydrofolate Dehydrogenase (NAD+)Folic AcidPolymorphism, GeneticTetrahydrofolatesGenotype5-Methyltetrahydrofolate-Homocysteine S-MethyltransferaseHyperhomocysteinemiaVitamin B 12Ferredoxin-NADP ReductaseHomozygoteFactor VGenetic Predisposition to DiseaseCystathionine beta-SynthaseThymidylate SynthaseThrombophiliaCase-Control StudiesFolic Acid DeficiencyGene FrequencyGlycine HydroxymethyltransferaseNADPH OxidaseHomocystinuriaHomocystineProthrombinRiboflavinAllelesOxidoreductasesPolymorphism, Single NucleotideRisk FactorsMethionineAminohydrolasesVitamin B ComplexFormate-Tetrahydrofolate LigaseMacedonia (Republic)Point MutationMutationS-AdenosylmethionineNADPVitamin B 6ThymineMethenyltetrahydrofolate CyclohydrolaseOdds RatioNeural Tube DefectsBetaineFertility Agents, MaleReduced Folate Carrier ProteinNitrate ReductasesCytosinePolymerase Chain ReactionAsian Continental Ancestry GroupMethotrexateSpinal DysraphismAbortion, HabitualHydroxymethylglutaryl CoA ReductasesPolymorphism, Restriction Fragment LengthAmino Acid Metabolism, Inborn ErrorsTranscobalaminsRibonucleotide ReductasesAlcohol OxidoreductasesPyridoxineDietary SupplementsNADH, NADPH OxidoreductasesDietColorectal NeoplasmsFluorodeoxyuridylateCytochrome-B(5) ReductaseFlavin-Adenine DinucleotideHeterozygoteNitrite ReductasesChinaDNA Mutational AnalysisGlutathione ReductaseFMN ReductaseTetrahydrofolate DehydrogenaseDNA MethylationGenetic Association StudiesThioredoxin-Disulfide ReductaseConfidence IntervalsNADPH-Ferrihemoprotein ReductaseKineticsGenetic VariationMolecular Sequence DataPharmacogeneticsBase SequenceCytochrome ReductasesPteroylpolyglutamic AcidsPregnancyRiskVascular DiseasesDihydropteridine ReductaseEnzyme StabilityHaplotypesJapanReference ValuesS-AdenosylhomocysteineCohort Studies