Abstract
Introduction: Vitamin B12 (Vit-B12) levels between the mothers and their infants in a neonatology unit were investigated and the effectiveness of oral methylcobalamin treatment in neonatal Vit-B12 deficiency was evaluated.
Materials and Methods: Eighty patients born between July 2018 and April 2020 at 34–42 weeks of gestation and who were found to have Vit-B12 deficiency were included in this cross-sectional study. Oral methylcobalamin was given to 40 patients, and 40 patients were followed up. Vit-B12 level and blood gas were measured in the umbilical cord blood of the infants, and a complete blood count was performed on the first day. Vit-B12 levels of the mothers were assessed. Complete blood count and Vit-B12 level were measured on the postnatal 30th day in patients who were followed up without treatment and 5 days after treatment in patients who received oral methylcobalamin treatment for 1 month.
Results: In the treatment group, the mean umbilical cord Vit-B12 level was 155.5 (±29.1) pg/ml, and the mean Vit-B12 level of the mothers was 158.8 (±57.6) pg/ml. The mean follow-up Vit-B12 level was 801.8 (±394.7) pg/ml. In the untreated group, the mean umbilical cord Vit-B12 level was 159.3 (±34.1) pg/ml, and the mean Vit-B12 level in mothers was 146.2 (±49.7) pg/ml. The mean follow-up Vit-B12 level was 189.2 (±57.6) pg/ml.
Conclusion: There was a positive correlation between umbilical cord Vit-B12 and mothers' Vit-B12 levels. Oral methylcobalamin treatment was found to be effective and safe in Vit-B12 deficiency.

Key words: Maternal vitamin B12 deficiency, newborn vitamin B12 deficiency, oral methylcobalamin treatment, umbilical cord