Association of Supplementation and Maternal Vitamin D Level Subgroup With Psychiatric Symptoms
internalizing problems, Depression, Psychiatric, depressive symptoms
REGRESSION
Abbreviations: ; CBCL, Childhood Behavior Checklist; MD, mean difference; OR, odds ratio.Psychiatric symptoms were assessed at ages 6 to 8 years using the CBCL.Groups 1 and 2 had maternal serum 25-hydroxyvitamin D (25[OH]D) levels less than 30 ng/mL (to convert to nanomoles per liter, multiply by 2.496), with child supplementation levels of 400-IU and 1200-IU vitamin DPopulation numbers differ for model 1 vs model 2 analyses owing to missing data for the Center for Epidemiological Studies Depression Scale covariate (group 1: 49 vs 48 children; group 2: 47 vs 44 children; group 3: 94 vs 83 children; group 4: 101 vs 91 children).In linear models, raw scores were square root transformed owing to skewness and converted to Z scores (0 = mean; 1 = 1 SD). MDs were calculated compared with children in group 1. In logistic regression models, raw scores were converted to Unadjusted model.Model adjusted for sex, season of birth, maternal depressive symptoms at birth, and parental single status at follow-up.In a post hoc subgroup analysis, 48 children in the 400-IU group with maternal 25(OH)D concentrations less than 30 ng/mL had higher internalizing problems scores compared with children in the 1200-IU group, including 44 children whose mothers had 25(OH)D concentrations below (adjusted MD, 0.49; 95% CI, 0.09-0.89; 