RESUMO
BACKGROUND: Vitamins B6, B12, and folate are essential for the formation and maintenance of the human brain, but studies evaluating these vitamins with early childhood development (ECD) in children under 5 y are limited and controversial. OBJECTIVES: To evaluate the association between vitamins B6, B12, and folate concentrations/status and ECD. METHODS: Data regarding 6520 children aged 6-59 mo from the ENANI-2019 (the Brazilian National Survey on Child Nutrition) were analyzed. ECD was assessed using the Survey of Well-being of Young Children's milestones questionnaire. Vitamin B6 concentration (nmol/L) was classified according to the tertile of the distribution and with the cutoff <20 nmol/L. Folate concentrations >45.3 nmol/L were classified as high, and vitamin B12 <150 pmol/L was deficient. The graded response model was used to estimate developmental age, and the developmental quotient (DQ) was calculated as the developmental age divided by chronological age. Multiple linear regression models were adjusted for confounders. RESULTS: The DQ mean (95% confidence interval) for Brazilian children was 0.99 (0.97-1.01). Children aged 6-23 mo [1.13 (1.10-1.16)] had a higher DQ mean than those aged 24-35 [0.99 (0.95-1.03)] and 36-59 mo [0.89 (0.86-0.92)]. Child age was inversely associated with DQ (ß = -0.007; P < 0.001). An interaction between child age and vitamin B12 deficiency in the DQ (ß = -0.005; P < 0.001) indicated that, in children aged 36-59 mo, the DQ was markedly lower in children with vitamin B12 deficiency than in those without vitamin B12 deficiency. Vitamin B6 concentrations were directly associated with the DQ (ß = 0.0004; P = 0.031) among children aged 24-59 mo in the adjusted model. No association was observed between folate status and DQ. CONCLUSIONS: In Brazil, the DQ is lower among older children and those with vitamin B12 deficiency. Vitamin B6 status was directly associated with the DQ in children aged 24-59 mo.