Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy

Abstract

Background In infants, vitamin B12 deficiency may be due to an inborn error of absorption and metabolism, or nutritional problems. Case presentation An exclusively breastfed 5-month-old Italian male infant, who was born after a normal full-term pregnancy to a vegan mother who was apparently daily treated with a multivitamin oral preparation during the second and third trimester, was hospitalised because of poor weight gain, feeding difficulties, severe pallor, muscle hypotonia and somnolence. Upon admission, his weight, length and head circumference were below the third percentile, he had an enlarged liver and spleen, and showed a significant delay in developmental milestones and communicative reactions. He had a hemoglobin level of 4.7 g/dL with an MCV of 84.2 fL, a white blood cell count of 4,680/mm 3 , and a platelet count of 45,000/mm 3 . His serum vitamin B12 level was 57 pg/mL (normal value 180–500 pg/mL) and serum folate level 12.8 ng/mL (normal value >3 ng/mL). The results of metabolic examinations excluded a cobalamin C disorder, whereas nutritional screening showed a serum iron concentration of 9 μg/dL and serum ferritin of 4 ng/mL. Magnetic resonance imaging of the brain showed mild dilatation of the lateral ventricles with diffuse delayed myelination. The child was diagnosed as having vitamin B12 and iron deficiency due to nutritional inadequacy and was immediately treated with packed red blood cells, intramuscular vitamin B12 injections, and iron supplementation. A few days after the start of therapy, his hemoglobin levels and other hematological parameters rapidly improved, and a clinical improvement was observed within few weeks. There was an increase in his achievement of developmental milestones, but his development was still retarded seven months after the start of therapy. Conclusion This case underlines the importance of adequately controlling maternal vitamin B12 intake during pregnancy by means of supplementation which, in the case of vegan mothers, should be significantly greater than that usually given. Moreover, the supplementation should be continued during lactation in order to avoid the development of signs of deficiency that may be associated with persistent neurological problems in infants. The case also highlights the need to consider vitamin B12 deficiency in infants with severe anemia even if their hematological parameters do not indicate megaloblastic anemia because the concomitant presence of substantial iron deficiency may modify the characteristics of the anemia.

Guidelines for the diagnosis and treatment of cobalamin and folate disorders

“…True cobalamin deficiency, with significant clinical problems, is considered to be rare in infants in developed countries and limited data exists on its prevalence. It is largely due to maternal deficiency (Bjorke Monsen et al , ; Guez et al , ), particularly when mothers have adhered to a strict vegetarian diet (Specker et al , ; Allen, ; Rasmussen et al , ). Rare cases of occult maternal pernicious anaemia causing cobalamin deficiency in infancy have also been reported (Banka et al , ).…”

Compromiso neurológico grave por déficit de vitamina B12 en lactantes hijos de madres veganas y vegetarianas

“…Puede haber pancitopenia. 8,11,15 Puede existir compromiso neurológico sin anemia; esta no es imprescindible para sospechar el diagnóstico. Otras manifestaciones son glositis, malabsorción, infertilidad, pigmentación cutánea y trombosis, secundaria al aumento de homocisteína plasmática.…”

“…5,11 El tratamiento consiste en la administración de B12; se inicia cianocobalamina intramuscular a razón de 1 mg/día de una a dos semanas, dependiendo de la gravedad, y luego, si hay mejoría clínica y de laboratorio, se continúa con dosis parenterales semanales o mensuales u orales en forma diaria. 8,5 Los parámetros hematológicos suelen mostrar el aumento de reticulocitos en una semana y la curación de la anemia megaloblástica de uno a dos meses. Los niveles de B12 se normalizan y los de homocisteína y AMM en orina descienden en 3-4 semanas.…”

Vitamin B12deficiency presenting as acute ataxia

“…This impairment of the mature nervous system develops over a period of months to years. In the pediatric population, who undergo extensive growth and development of their brains, cobalamin deficiency can cause severe impairment in just weeks to months 4. Supplementation with cobalamin can correct the haematological and metabolic disturbances, but early recognition and treatment of this nutritional deficiency is key to preventing long-term neurodevelopmental sequelae.…”