title: Nutritional vitamin B12 deficiency in infancy: three case reports and a review of the literature.
abstract: Three cases of vitamin B12 deficiency that occurred during infancy are presented. These cases appeared to be the result of pre-existing maternal deficiency. All three infants demonstrated evidence of neurodevelopmental delay at presentation, and one had sustained loss of milestones and developed involuntary motor movements. Prior to the initiation of therapy, all three infants were anemic: one was thrombocytopenic and one pancytopenic. In all three cases the hematologic and neurologic abnormalities were corrected with vitamin B12 therapy. The literature is reviewed and discussed with respect to the mechanism of the infants' vitamin B12 deficiency and neurodevelopmental manifestations.
authors.affiliation: Department of Pediatrics, Hospital for Sick Children, University of Toronto, Ontario.
authors.forename: J J
authors.initials: JJ
authors.lastname: Doyle
authors.forename: A M
authors.initials: AM
authors.lastname: Langevin
authors.forename: A
authors.initials: A
authors.lastname: Zipursky
mesh_terms: D000749:Anemia, Megaloblastic / Q000209:etiology*; D000752:Anemia, Pernicious / Q000235:genetics; D001942:Breast Feeding; D002675:Child, Preschool; D014676:Diet, Vegetarian / Q000009:adverse effects; D005260:Female; D006801:Humans; D007223:Infant; D007228:Infant Nutrition Disorders / Q000209:etiology*; D008297:Male; D008431:Maternal-Fetal Exchange; D008895:Milk, Human; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000503:physiopathology; D014805:Vitamin B 12 / Q000032:analysis / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000188:drug therapy / Q000209:etiology*
chemical_list: D014805:Vitamin B 12