Background: Prenatal depression is associated with offspring behavioral problems, but heterogeneity in the strength of this association is not well understood. Maternal vitamin D concentration during pregnancy is important for fetal brain development and may help explain this variability, with potential differences by timing of exposure and maternal race.
Methods: Using data from 1,451 mother-child pairs in the Environmental influences on Child Health Outcomes cohort, linear mixed-effects models examined associations between prenatal depressive symptom severity, gestational 25-hydroxy-vitamin D (25[OH]D) concentrations, and internalizing and externalizing behaviors in preschool-aged children. Analyses were stratified by common 25(OH)D deficiency thresholds, prenatal timing, and race.
Results: Prenatal depressive symptom severity was associated with greater child internalizing ( β = 0.18, 95% CI = 0.11, 0.25) and externalizing ( β = 0.21, 95% CI = 0.14, 0.28) behaviors. Gestational 25(OH)D concentration did not moderate depression effect estimates in adjusted models. In stratified analyses, the association between prenatal depressive symptoms and child externalizing behaviors persisted regardless of 25(OH)D threshold levels, but the association with internalizing behaviors attenuated at 25(OH)D < 20 ng/mL. Timing of 25(OH)D measurement (early/late pregnancy) did not modify relationships. Higher gestational 25(OH)D was associated with fewer externalizing problems among offspring of Black mothers only.
Conclusions: Prenatal depressive symptoms showed robust associations with child behavioral problems, largely independent of gestational 25(OH)D. However, attenuated risk for internalizing behaviors with low vitamin D levels warrants investigation of social-environmental factors.
Keywords: depression; externalizing and internalizing behaviors; pregnancy; vitamin D.