Vitamin B12 Deficiency in Newborns and their Mothers—Novel Approaches to Early Detection, Treatment and Prevention of a Global Health Issue

Summary Vitamin B12 deficiency, mostly of maternal origin in newborns, is a well treatable condition but can cause severe neurologic sequelae. In women of childbearing age and pregnant women worldwide vitamin B12 deficiency has been reported with frequencies of 10%–50%. Children with vitamin B12 deficiency are asymptomatic at birth but may develop severe multisystemic symptoms, including irreversible developmental impairment in the second half-year of life. Early detection of vitamin B12 deficiency allows for presymptomatic treatment. This article provides an overview over the function of vitamin B12 and discusses causes and frequency of vitamin B12 deficiency in newborns, infants, and women of childbearing age. It describes novel successful approaches to newborn screening (NBS) for vitamin B12 deficiency and results of a pilot study which performed systematic NBS for vitamin B12 deficiency using so-called second-tier strategies by measuring homocysteine and methylmalonic acid in dried blood spots. Recommendations for diagnostics in mothers of children with vitamin B12 deficiency are described as well as results of systematic work-up in mothers and treatment and follow-up of children with vitamin B12 deficiency detected by NBS. Treatment options of vitamin B12 deficiency are presented including a newly developed standardized supplementation scheme with exclusively oral vitamin B12 supplementation. Recommendations for preventive approaches to vitamin B12 deficiency for children and mothers are stated. Many children worldwide could benefit from systematic inclusion of vitamin B12 deficiency into NBS panels. In addition, preventive approaches to maternal vitamin B12 deficiency should be implemented systematically during maternal care.