Eur J Pediatr. 1992 Mar; 151(3): 218-20.
Nutritional vitamin B12 deficiency: two cases detected by routine newborn urinary screening.
Department of Paediatrics, HÃ´pital Sainte-Justine, CÃ´te Ste-Catherine, MontrÃ©al, QuÃ©bec, Canada.
We describe two asymptomatic newborns with nutritional vitamin B12 deficiency in whom increased urinary methylmalonic acid was detected by routine neonatal screening at 3 weeks of age. Both infants were exclusively breast-fed. One mother suffered from pernicious anaemia, and the other was a strict vegetarian. Both mothers had no clinical or haematological abnormality, aside from a borderline mean corpuscular volume for the vegetarian mother. This report illustrates the early appearance of functional vitamin B12 deficiency in breast-fed infants of vitamin B12-depleted mothers. It also demonstrates that urinary methylmalonic acid measurement is a sensitive indicator of tissue vitamin B12 deficiency.