Vitamin B12 Deficiency: A Treatable Cause of Developmental Delay In Infancy

Abstract

Neuronal regression and developmental delay in infants has varied aetiology, and vitamin B12 deficiency is a rare but treatable cause. Vitamin B12 deficiency in infancy is a rare but treatable cause of developmental delay and neuronal regression. Maternal vitamin B12 deficiency is usually secondary to pernicious anaemia or to a strict vegetarian diet and can cause serious neurological abnormalities among exclusively breastfed infants. Clinical picture include apathy, irritability, poor eye contact, lethargy, vomiting and feeding difficulties, developmental regression, hypotonia, tremor, myoclonic jerks, involuntary movements and seizures.1 Neurological manifestations usually appear between 2 and 12 months of age.2 Signs of cerebral atrophy have been detected on neuroimaging studies. Infants born to vitamin-B12-deficient mothers have a very limited hepatic stock of vitamin B12 and can develop symptoms within a few months. Persistent neurological damage can be prevented with early diagnosis and treatment.3, 4 Although supplementation of vitamin B12 appears to result in a rapid clinical improvement, there is a concern over long-term prognosis with cognitive impairment. It is important to emphasise that vitamin B12 supplementation during pregnancy should be provided for strict vegetarians and individuals with pernicious anaemia to avoid irreversible neurological damage.