New-born screening and vitamin B12 deficiency: model of management and description of a case history

Objectives and Study Vitamin B12 is essential for fetal and postnatal neurodevelopment. Newborn screening can identify neonatal deficiency secondary to maternal depletion. The aim of the present project is to describe the neuro-metabolic phenotype at birth and to identify main causes of maternal deficiency. Methods From November 2021 to November 2022, 24 infants out of 66.000 screened by Buzzi’s Hospital Laboratory Screening center were referred to our centre for vitamin B12 deficiency. The first evaluation has been performed within 30 days of life, including blood and urinary exams, neurological evaluation and brain magnetic resonance imaging (MRI) with spectroscopy. Causes of maternal deficiency have been investigated and hydroxycobalamin i.m.1000 mcg has been administered both to mother and child. Regular multidisciplinary controls have been planned till 24 months, with re-evaluation of biochemical parameters, imaging and administration of therapy, if necessary. Annually follow-up has been scheduled until 12 years, with brain MRI at 6 years and neurological function tests at 6 and 12 years. Results Thirteen out of 24 patients were exclusively breastfed, 8 mixed fed, 3 formula fed. Fourteen families were from Middle-East Asia, 1 from Africa, 1 from South-America, 2 from Eastern Europe and 7 from Italy. Dietary recalls revealed an inadequate vitamin B12 intake in 20 mothers (12 followed a vegetarian diet, 1 had hyperemesis gravidarum, 2 anti-parietal-cells antibodies positive, 1 MTHFR mutation, 2 previous bariatric surgery and obesity disorder). At first evaluation 23 infants had low vitamin B12 levels (mean 197,5 pmol/L); the patient with normal value was formula fed. Neurological examination and brain MRI (performed in 10 infants) were normal in all patients. Conclusions Inadequate maternal intake is the main cause of vitamin B12 deficiency in o!springs, highlighting the importance of prevention strategies, through dietary recalls and interventions. Results from our project could define a model of medical management of this condition, actually lacking.