Health Outcomes of Infants with Vitamin B12 Deficiency Identified by Newborn Screening and Early Treated

Objective To evaluate the clinical outcomes at age 1.5 ± 0.5 years of infants with vitamin B12 deficiency identified by newborn screening (NBS). Study design Prospective multicenter observational study on health outcomes of 31 infants with vitamin B12 deficiency identified by NBS. Neurodevelopment was assessed by the Denver Developmental Screening Test. Results In 285 862 newborns screened between 2016 and 2019, the estimated birth prevalence of vitamin B12 deficiency was 26 in 100 000 newborns, with high seasonal variations (lowest in summer: 8 in 100 000). Infants participating in the outcome study (N = 31) were supplemented with vitamin B12 for a median (range) of 5.9 (1.1-16.2) months. …