It has been reported that physical and neuro-motor developmental delay were shown in children with anemia resulting from vitamin B12 deficiency. There have not yet been enough studies on the effects of vitamin B12 deficiency on the physical, social and neuro-motor development of infants who have no complaint and appear healthy. In our prospective study, 211 healthy infants aged 6-12 months who were brought to four different health centers for vaccination and for well-baby check-up were enrolled. At the initial visit, weight, length and head circumference of children were measured and percentile values were recorded. The Ankara Development Surveillance Inventory (AGTE) test was used to evaluate the neuro-motor and social development of the children. Vitamin B12 deficiency was found in 84 (39.8%) of the children. The rate of children whose weight and head circumference percentiles were <10thpercentile was significantly higher in the vitamin B12-deficient group. While there was no significant difference in hemoglobin levels between the two groups (deficient or normal vitamin B12), AGTE T-point (AGTETP) scores of the first group with vitamin B12 deficiency were statistically lower than in the vitamin B12 normal group (33.29±7.61 and 47.91±6.72, respectively) and the rate of children with low AGTETP score was higher (77.38% and 13.39%, respectively). The children with vitamin B12 deficiency were treated; three months after treatment, 84.2% of these children’s AGTETP scores had increased to normal levels, and the weight and head circumference percentiles had improved significantly. To conclude, our study has shown that vitamin B12 deficiency in 6-12-month-old healthy infants can disturb the physical, social and neuro-motor development of children before hematologic disorders develop.

Keywords: B12 vitamini eksikliği, Ankara Gelişim Tarama Envanteri (AGTE), nöromotor gelişim, sosyal gelişim, fiziksel gelişim.