Inverse associations between cord vitamin D and attention deficit hyperactivity disorder symptoms: A child cohort study.

ABSTRACT

OBJECTIVE: To examine the association between cord 25-hydroxyvitamin D2+3 (25(OH)D) and attention deficit hyperactivity disorder symptoms in toddlers, using Child Behaviour Checklist for ages 1.5-5. METHOD: In a population-based birth cohort, a Child Behaviour Checklist for ages 1.5-5 questionnaire was returned from parents of 1233 infants with mean age 2.7 (standard deviation 0.6) years. Adjusted associations between cord 25(OH)D and Child Behaviour Checklist-based attention deficit hyperactivity disorder problems were analysed by multiple regression. Results The median cord 25(OH)D was 44.1 (range 1.5-127.1) nmol/L. Mean attention deficit hyperactivity disorder problem score was 2.7 (standard deviation 2.1). In adjusted analyses, cord 25(OH)D levels >25 nmol/L and >30 nmol/L were associated with lower attention deficit hyperactivity disorder scores compared to levels ⩽25 nmol/L ( p = 0.035) and ⩽30 nmol/L ( p = 0.043), respectively. The adjusted odds of scoring above the 90th percentile on the Child Behaviour Checklist-based attention deficit hyperactivity disorder problem scale decreased by 11% per 10 nmol/L increase in cord 25(OH)D. CONCLUSION: An inverse association between cord 25(OH)D and attention deficit hyperactivity disorder symptoms in toddlers was found, suggesting a protective effect of prenatal vitamin D.