Vitamin b-12 deficiency.
D000752:Anemia, Pernicious / Q000378:metabolism; D005767:Gastrointestinal Diseases / Q000150:complications / Q000378:metabolism; D006801:Humans; D007082:Ileum / Q000378:metabolism; D007267:Injections; D007437:Intrinsic Factor / Q000276:immunology; D008297:Male; D008875:Middle Aged; D014805:Vitamin B 12 / Q000097:blood / Q000378:metabolism / Q000652:urine; D014806:Vitamin B 12 Deficiency / Q000209:etiology / Q000378:metabolism*
D007437:Intrinsic Factor; D014805:Vitamin B 12