Vitamin B12 Deficiency Associated With Low Breast-Milk Vitamin B12 Concentration in an Infant Following Maternal Gastric Bypass Surgery

Abstract

Vitamin B 12 (cobalamin) deficiency is uncommon in infancy. It may be associated with (1) inadequate dietary intake (eg, breast-fed infants of strict vegetarian [vegan] mothers); (2) congenital defects in intestinal absorption and transportation (eg, absence or malfunction of gastric intrinsic factor, selective ileal transport defect, or transcobalamin II deficiency); or (3) defects in intracellular processing. 1,2 The main clinical feature of vitamin B 12 deficiency is megaloblastic anemia. We herein describe a female infant who presented with developmental delay at 12 months. She was recognized to have macrocytic anemia and methylmalonicaciduria associated with vitamin B 12 deficiency. Her anemia and developmental status improved after parenteral administration of cyanocobalamin. It appears that this deficiency developed after she was exclusively breast-fed by a mother with inadequate breast-milk vitamin B 12 levels secondary to gastric bypass surgery and a semivegetarian diet. Report of a Patient. A 12-month-old female infant was referred for