Intestinal AbsorptionRanitidineGymnemaHibiscusBiological AvailabilityAdministration, OralAbsorptionHistamine H2 AntagonistsVitamin B 12 DeficiencyVitamin B 6DietVitamin AVitaminsVitamin DCimetidineBismuthVitamin EAnti-Ulcer AgentsFamotidineVitamin B 12Vitamin B ComplexVitamin A DeficiencyPyridoxineVitamin D DeficiencyFuransDuodenal UlcerMagnesium HydroxideGastric Acidity DeterminationGastric AcidOmeprazoleSucralfateTranscobalaminsFolic AcidVitamin B DeficiencyCobalt IsotopesAntacidsVitamin K 1Skin AbsorptionStomach UlcerVitamin E DeficiencyHeartburnAscorbic AcidAluminum HydroxideDouble-Blind MethodDietary SupplementsMalabsorption SyndromesJejunumCholecalciferolAnemia, PerniciousSpectrophotometry, AtomicVitamin K DeficiencyX-Ray Absorption SpectroscopyPyridoxal PhosphateIntrinsic FactorVitamin B 6 DeficiencyReceptors, Histamine H2RiboflavinFolic Acid DeficiencyIronHydrogen-Ion ConcentrationThiamineSpectrophotometryGastric JuiceDrug InteractionsMethylmalonic AcidIntestine, SmallClarithromycinEnprostilSpectrum AnalysisAnemia, MegaloblasticDuodenumCross-Over StudiesDose-Response Relationship, DrugTime FactorsZincHistamine AntagonistsMetronidazoleEsophagitis, PepticHelicobacter pyloriReceptors, CalcitriolAnemia, Macrocytic2-PyridinylmethylsulfinylbenzimidazolesHydroxocobalaminPyridoxic AcidDrug Therapy, CombinationAmoxicillinPyridoxalKineticsHelicobacter InfectionsHistaminePeptic UlcerCalcium CarbonateAvitaminosisSchilling TestVitamin D-Binding ProteinCalcium, DietaryCaco-2 CellsIntestinesHalf-LifeZinc Radioisotopes