HomocysteineHyperhomocysteinemiaVitamin B 12Folic AcidMethylenetetrahydrofolate Dehydrogenase (NAD+)Methylenetetrahydrofolate Reductase (NADPH2)Oxidoreductases Acting on CH-NH Group DonorsPyridoxineRisk FactorsRenal DialysisGenotypeCase-Control StudiesVitamin B ComplexMethylmalonic AcidVitamin B 6Vitamin B 12 DeficiencyFolic Acid DeficiencyHomocystineMethionineFluorescence Polarization ImmunoassayRiboflavinCystathionine beta-SynthaseBetaineFastingCystathionineDietary SupplementsTranscobalaminsFood, FortifiedSarcosineCoffeeVitaminsTetrahydrofolatesCerealsNutritional StatusS-Adenosylhomocysteine5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase