Maternal Folic Acid Supplementation and Childhood Metabolic Health: Analyzing Direct and Indirect Effects

Abstract

This study examines the direct and indirect effects of maternal folic acid (FA) supplementation on childhood metabolic outcomes, including blood pressure (BP), insulin resistance (HOMA-IR), and insulin sensitivity (QUICKI), with body mass index (BMI), waist circumference (WC), and skinfold thickness as mediators. This cross-sectional study analyzed data from 2577 children (9–13 years) from the Healthy Growth Study (2007–2009, Greece). Maternal FA intake was reported via parental questionnaires. BMI, WC, and skinfold thickness were measured using standardized protocols. BP, fasting glucose, and insulin were assessed to compute HOMA-IR and QUICKI. Structural equation modeling evaluated direct and indirect effects, adjusting for maternal, pregnancy, and child-related confounders. FA supplementation had no direct effect. However, indirect effects via WC were associated with lower SBP (β = −0.69, p = 0.036) and DBP (β = −0.36, p = 0.041), improved insulin sensitivity (QUICKI: β = 0.0018, p = 0.044), and reduced insulin resistance (HOMA-IR: β = −0.1099, p = 0.047). Skinfold thickness also mediated BP reductions. BMI was not a significant mediator (all p > 0.05). Maternal FA intake may indirectly influence childhood metabolic health via adiposity markers, emphasizing the need for targeted maternal nutrition interventions to improve childhood metabolic outcomes.