Anemia, PerniciousIntrinsic FactorVitamin B 12 DeficiencyAchlorhydriaVitamin B 12AnemiaSchilling TestAnemia, MacrocyticVitamin B 6Cobalt IsotopesAnemia, MegaloblasticVitamin AHydroxocobalaminVitaminsPostgastrectomy SyndromesGastrinsParietal Cells, GastricVitamin DVitamin EVitamin A DeficiencyAnemia, HypochromicFolic Acid DeficiencyGastric JuiceFolic AcidGastritis, AtrophicGastric MucosaVitamin B ComplexVitamin D DeficiencyPyridoxineMalabsorption SyndromesGastritisCobalt RadioisotopesAnemia, AplasticAnemia, HemolyticCarcinoid TumorEnterochromaffin CellsVitamin B DeficiencyZollinger-Ellison SyndromeAutoimmune DiseasesTranscobalaminsAutoantibodiesEndocrine System DiseasesVitiligoVitamin E DeficiencyStomachEthylaminesGastroscopyFanconi AnemiaAgammaglobulinemiaPolypsGastric FundusEdrophoniumVitamin K 1