RESUMO
AIM: In developing countries, nutritional vitamin B(12) deficiency in infants due to maternal diet without adequate protein of animal origin has some characteristic clinical features. In this study, haematological, neurological and gastrointestinal characteristics of nutritional vitamin B(12) deficiency are presented. METHODS: Hospital records of 27 infants diagnosed in a paediatric haematology unit between 2000 and 2008 were evaluated retrospectively. RESULTS: The median age at diagnosis was 10.5 months (3-24 months). All the infants were exclusively breast fed and they presented with severe nonspecific manifestations, such as weakness, failure to thrive, refusal to wean, vomiting, developmental delay, irritability and tremor in addition to megaloblastic anaemia. The diagnosis was confirmed by complete blood counts, blood and marrow smears and serum vitamin B(12) and folic acid levels. The median haemoglobin level was 6.4 g/dL (3.1-10.6) and mean corpuscular volume (MCV) was 96.8 fL (73-112.3). Some patients also had thrombocytopaenia and neutropaenia. All the infants showed clinical and haematological improvement with vitamin B(12) administration. Patients with severe anaemia causing heart failure received packed red blood cell transfusions as the initial therapy. CONCLUSION: Paediatricians must consider nutritional vitamin B(12) deficiency due to maternal dietary deficiency in the differential diagnosis of some gastrointestinal, haematological, developmental and neurological disorders of infants with poor socioeconomic status. Delay in diagnosis may cause irreversible neurological damage.
