Sensitivity to cyanocobalamin and hydroxocobalamin.
D000284:Administration, Oral; D000368:Aged; D000752:Anemia, Pernicious / Q000150:complications; D004342:Drug Hypersensitivity; D004417:Dyspnea / Q000139:chemically induced; D005260:Female; D006261:Headache / Q000139:chemically induced; D006801:Humans; D006879:Hydroxocobalamin / Q000009:adverse effects*; D008875:Middle Aged; D014581:Urticaria / Q000139:chemically induced*; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000009:adverse effects*
D014805:Vitamin B 12; D006879:Hydroxocobalamin