Anemia, PerniciousAnemia, MyelophthisicAnemiaIntrinsic FactorAchlorhydriaAnemia, MacrocyticSchilling TestVitamin B 12Vitamin B 12 DeficiencyAnemia, MegaloblasticCobalt IsotopesAnemia, HypochromicAnemia, AplasticHydroxocobalaminGastrinsPostgastrectomy SyndromesParietal Cells, GastricAnemia, HemolyticFanconi AnemiaGastric JuiceGastritis, AtrophicGastric MucosaAnemia, Hemolytic, AutoimmuneGastritisFolic Acid DeficiencyCarcinoid TumorEnterochromaffin CellsAnemia, Sickle CellZollinger-Ellison SyndromeAutoantibodiesAutoimmune DiseasesCobalt RadioisotopesAnemia, SideroblasticMalabsorption SyndromesEndocrine System DiseasesEthylaminesVitiligoStomachGastroscopyPolypsInfectious Anemia Virus, EquineHemoglobinsAgammaglobulinemiaAnemia, RefractoryFolic AcidGastric FundusEdrophonium