Cobalamin supplementation improves motor development and regurgitations in infants: results from a randomized intervention study.

During infancy, minor developmental delays and gastrointestinal complaints are common, as is a biochemical profile indicative of impaired cobalamin status. We investigated whether cobalamin supplementation can improve development or symptoms in infants with biochemical signs of impaired cobalamin function and developmental delay or feeding difficulties. Infants <8 mo of age (n = 105) who were referred for feeding difficulties, subtle neurologic symptoms, or delayed psychomotor development were assessed for cobalamin status [by the measurement of serum cobalamin, plasma total homocysteine (tHcy), and plasma methylmalonic acid (MMA)]. Infants with biochemical signs of impaired cobalamin function, defined as a plasma tHcy concentration ≥6.5 μmol/L (n = 79), were enrolled in a double-blind, randomized controlled trial to receive 400 μg hydroxycobalamin intramuscularly (n = 42) or a sham injection (n = 37). Motor function [Alberta Infants Motor Scale (AIMS)] and clinical symptoms (parental questionnaire) were recorded at entry and after 1 mo. During follow-up, cobalamin supplementation changed all markers of impaired cobalamin status (ie, plasma tHcy decreased by 54%, and MMA decreased by 84%), whereas no significant changes were seen in the placebo group (P < 0.001). The median (IQR) increase in the AIMS score was higher in the cobalamin group than in the placebo group [7.0 (5.0, 9.0) compared with 4.5 (3.3, 6.0); P = 0.003], and a higher proportion showed improvements in regurgitations (69% compared with 29%, respectively; P = 0.003). In infants with biochemical signs of impaired cobalamin function, 1 intramuscular injection of cobalamin resulted in biochemical evidence of cobalamin repletion and improvement in motor function and regurgitations, which suggest that an adequate cobalamin status is important for a rapidly developing nervous system. This trial was registered at clinicaltrials.gov as NCT00710359 and NCT00710138.