Vitamin B12 deficiency in newborns and infants—Causes, early detection, diagnostics and presentation of a primary oral treatment scheme

Abstract

Background: Vitamin B12 deficiency is mostly of maternal origin in newborns. Children with severe unrecognized vitamin B12 deficiency are asymptomatic at birth but develop severe multisystemic symptoms, including irreversible neurological impairment and permanent developmental disorders, which are mostly clinically first recognized in the second half-year of life. Early detection enables presymptomatic treatment of vitamin B12 deficiency. Strategies for detection of vitamin B12 deficiency by newborn screening (NBS) are currently being evaluated in pilot studies. Objective: This article provides an overview of possible causes of vitamin B12 deficiency and presents novel successful approaches to newborn screening for vitamin B12 deficiency as well as recommendations for diagnostics of mother and child. Treatment of vitamin B12 deficiency in newborns and infants is mainly performed by intramuscular injections. As an alternative the authors present a standardized regimen of exclusively oral vitamin B12 supplementation. Results: In the context of the pilot project “Newborn Screening 2020” at the Heidelberg NBS center a standardized regimen of exclusively oral vitamin B12 supplementation has been developed and successfully utilized for children with vitamin B12 deficiency detected by NBS. This consists of oral vitamin B12 supplementation 0.5 mg per day (liquid preparation) for 3 days, followed by 0.1 mg per day. During the first week folic acid 0.4 mg per day is also orally supplemented. After normalization of all markers of vitamin B12 metabolism (especially the functional markers methylmalonic acid and homocysteine) oral vitamin B12 supplementation is continued in a maintenance dosage of 5 µg/day during breastfeeding until complementary foods containing meat or vitamin B12-containing formula have been reliably introduced. Conclusion: The regimen of oral vitamin B12 supplementation presented here is an effective, cost-efficient, painless, and therefore especially child-friendly treatment.