Rodrigues, VDias, ABrito, MJGalvão, ICordeiro Ferreira, G2013-11-192013-11-192011BMJ Case Reports 2011 May 16 ; doi:10.1136/bcr.02.2011.3835http://hdl.handle.net/10400.17/1553Vitamin B 12 or cobalamin deficiency, a rare clinical entity in pediatric age, is found most exclusively in breastfed infants, whose mothers are strictly vegetarian non-supplemented or with pernicious anaemia. In this article, the authors describe a 10-month-old infant admitted for vomiting, refusal to eat and prostration. The infant was exclusively breastfed and diffi culties in introduction of new foods were reported. Failure to thrive since 5 months of age was also noticed. Laboratory evaluation revealed severe normocytic normochromic anaemia and cobalamin defi cit. A diagnosis of α-thalassemia trait was also made. Maternal investigation showed autoimmune pernicious anaemia. This case shows the severity of vitamin B 12 deficiency and the importance of adopting adequate and precocious measures in order to prevent potentially irreversible neurologic damage.engVitamina B 12Anemia MegaloblásticaCriançaHDE PEDjournal article