title: False normal vitamin B(12) levels caused by  assay error.
authors: Meander Medical Centre.
authors: L A
authors: LA
authors: Boven
authors: M
authors: M
authors: van Wijnen
mesh_terms: D002624:Chemistry, Clinical / Q000592:standards*; D003951:Diagnostic Errors; D004900:Erythroblasts / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D014805:Vitamin B 12 / Q000032:analysis* / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000175:diagnosis*
chemical_list: D014805:Vitamin B 12