An infant and mother with severe B.sub.12 deficiency: vitamin B.sub.12 status assessment should be determined in pregnant women with anaemia

• Published in: European journal of clinical nutrition 2017-08, Vol.71 (8), p.1013
• Main Authors: Sobczynska-Malefora, A, Ramachandran, R, Cregeen, D, Green, E, Bennett, P, Harrington, D J, Lemonde, H A
• Format: Article
• Language: English
• Subjects: Care and treatment; Case studies; Causes of; Children; Complications and side effects; Developmental delay; Diagnosis; Diseases; Health aspects; Iron deficiency diseases; Mothers; Pediatric research; Prenatal influences; Vitamin B12 deficiency
• ISSN: 0954-3007
• DOI: 10.1038/ejcn.2017.85

The vitamin B.sub.12 status of infants depends on maternal B.sub.12 status during pregnancy, and during lactation if breastfed. We present a 9-month-old girl who was admitted to the metabolic unit for assessment of developmental delay. She was exclusively breastfed and the introduction of solids at 5 months was unsuccessful. Investigations revealed pancytopenia, undetectable B.sub.12 and highly elevated methylmalonic acid and homocysteine. Methylmalonic acid and homocysteine normalised following B.sub.12 injections. Marked catch-up of developmental milestones was noted after treatment with B.sub.12. Investigations of parents showed normal B.sub.12 in the father and combined B.sub.12 and iron deficiency in the mother. Maternal B.sub.12 deficiency, most likely masked by iron deficiency, led to severe B.sub.12 deficiency in the infant. Exclusive breastfeeding and a subsequent failure to wean exacerbated the infant's B.sub.12 deficiency leading to developmental delay. This case highlights the need for development of guidelines for better assessment of B.sub.12 status during pregnancy.