Vitamin B12 deficiency in newborns: impact on individual's health status and healthcare costs.

Objectives: The identification of vitamin B12 (B12) deficiency in the newborn may prevent neurological damage and a delay in the normal growth. In this study we characterized the incidence of B12 deficiency in newborns, the costs associated to the clinical diagnosis and management, and the relevance to optimize the use of cobalamin biomarkers during treatment follow-up.

Methods: Starting from a continuous case series of 146,470 screened newborns (November, 1st 2021- December, 3rd 2023), the Regional Reference Laboratory for Neonatal Screening identified 87 newborns having altered levels of biomarkers of cobalamin metabolism measured by Newborn Screening. These subjects were confirmed with a nutritional B12 deficiency of maternal origin by performing the serum B12 measurements and plasma homocysteine (Hcy) both on the newborns and respective mothers. A cost analysis was performed to characterize the costs/year of identifying and managing B12 deficiency cases.

Results: At baseline, median (interquartile range) serum B12 levels of 185.0 (142.3-246.0) ng/L and threefold increased plasma Hcy concentrations above the normal level confirmed a severe condition of deficiency in the newborns. After intramuscular B12 supplementation, serum B12 measured at the first follow up visit showed a fivefold increase, and the levels of Hcy returned to normal. From the healthcare perspective, the costs for diagnosing and managing all newborns with B12 deficiency is 188,480 €/year.

Conclusions: Preventing B12 depletion in newborns lowers healthcare costs and likely improves their health outcomes. Further studies are however required to address the clinical pathway to identify, treat and monitor pregnant women with marginal and low B12 status, in order to achieve these goals.