Defining Optimal Cobalamin Status for Neonates and Infants

Background: An optimal cobalamin status is necessary for normal neurodevelopment. Objective: To give a description of the epidemiology, pathophysiology and diagnostic challenges related to cobalamin insufficiency in neonates and infants in order to prevent its occurence. Results: Inadequate cobalamin status is prevalent among neonates and young infants, due to a high prevalence of maternal cobalamin deficiency, exclusive breastfeeding for extended periods and late introduction of animal food. Cobalamin insufficiency is associated with delayed neurodevelopment and subtle clinical symptoms like feeding difficulties, regurgitations and constipation in young infants. Early diagnosis and treatment of impaired cobalamin status is important to prevent neurologic damage. Conclusion: Clinical suspicion of cobalamin insufficiency in infants should infer immediate biochemical testing and a plasma total homocysteine > 5.0 µmol/L indicate cobalamin insufficiency in need of intramuscular treatment with hydroxycobalamin, followed by introduction of animal food after 4 months of age.