ObjectiveThis study aimed to examine associations of maternal folic acid supplementation (FAS) during pregnancy with childhood overweight or obesity (OWO) or adiposity.MethodsIn a population-based cohort of 1479 children, maternal FAS during pregnancy was assessed retrospectively by questionnaires. BMI and body fat percentages were measured at a mean age of 6.4 years. Pertinent factors were accounted for in data analyses.ResultsMaternal FAS during pregnancy was negatively associated with OWO (adjusted odds ratio: 0.70; 95% CI: 0.50 to 0.99). There were inverse associations of maternal FAS during pregnancy with BMI z score (beta: -0.22; 95% CI: -0.39 to -0.05), whole body fat percentage (beta: -1.28; 95% CI: -2.27 to -0.30), trunk fat percentage (beta: -1.41; 95% CI: -2.78 to -0.04), and limb fat percentage (beta: -1.31; 95% CI: -2.32 to -0.30). Stratified analyses found inverse associations of FAS during pregnancy with OWO, BMI z score, and body fat percentages predominantly among children without breastfeeding and whose parents had a below-tertiary educational level.ConclusionsThis study provides novel evidence that maternal FAS during pregnancy was significantly associated with a decreased risk of childhood OWO and adiposity, particularly among children with no breastfeeding and lower parental educational level.
