"Serum B12" and the diagnosis of cobalamin deficiency.
D003951:Diagnostic Errors; D006801:Humans; D011865:Radioisotope Dilution Technique / Q000592:standards; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000175:diagnosis*
D014805:Vitamin B 12