title: Vitamin B12 deficiency in a 9-month-old boy.
abstract: We present a 9-month-old boy with megaloblastic anaemia, neutropenia and hypogammaglobulinaemia due to vitamin B12 deficiency. The deficiency was secondary to prolonged exclusive breastfeeding with inadequate nutritional amounts of vitamin B12 from the mother. There were no clinical or biological signs of maternal anaemia or macrocytosis. Treatment with oral vitamin B12 rapidly improved the biological findings of the child. Vitamin B12 deficiency should be considered in infants older than 2 months presenting with failure to thrive, neurocognitive retardation or even pancytopenia and hypogammaglobulinaemia, even in the absence of any signs of maternal anaemia or macrocytosis. Therefore, evaluation of vitamin B12 status during pregnancy and lactation is necessary in order to prevent B12 deficiency and its possible long-term effects in infants.
  
  
  CONCLUSIONS
  Further studies should be conducted to evaluate the optimal oral dosage of vitamin B12 in children since limited data on the use of oral B12 substitution are available.
authors.affiliation: Department of Hematology and Oncology, Université Libre de Bruxelles, Queen Fabiola Children's Hospital, Brussels, Belgium. christine_quentin@hotmail.com
authors.forename: Christine
authors.initials: C
authors.lastname: Quentin
authors.forename: Sophie
authors.initials: S
authors.lastname: Huybrechts
authors.forename: Laurence
authors.initials: L
authors.lastname: Rozen
authors.forename: Corinne
authors.initials: C
authors.lastname: De Laet
authors.forename: Anne
authors.initials: A
authors.lastname: Demulder
authors.forename: Alina
authors.initials: A
authors.lastname: Ferster
mesh_terms: D001942:Breast Feeding / Q000009:adverse effects*; D004032:Diet; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D014806:Vitamin B 12 Deficiency / Q000175:diagnosis* / Q000209:etiology