(OR17-06-22) Maternal Android Adiposity and Vitamin D Status in Lactation Are Positive Predictors of Child Adiposity and Vitamin D Status at 2 Years of Age: A Follow-Up Study From Montréal

Objectives: Recent evidence suggests that fetal exposure to both maternal excess adiposity and low maternal vitamin D status is associated with body composition of the children. The objective was to explore whether maternal android adiposity and maternal serum 25-hydroxyvitamin D (25(OH)D) during early lactation relate to child adiposity and vitamin D status at 2 years of age.

Methods: The present study is a follow-up of a sub-group who completed a double-blinded randomized parallel group-controlled trial of vitamin D supplementation (400 or 1000 IU/d) across infancy (NCT02563015). In this follow-up, 68 (49%) children (37 males, 31 females) returned at 24 months of age; the study was closed at the onset of the COVID-19 pandemic precluding follow-up in the remainder. Body composition (dual-energy X-ray absorptiometry) and serum 25(OH)D (immunoassay) were measured at baseline (0.2-1.5 mo postpartum) in mothers and at 24 months of age in children. Data were analyzed using a linear fixed effects model with covariates (sex, skin tone, child age, maternal 25(OH)D concentrations, parental age, and maternal android fat mass) followed by Tukey post hoc tests adjusted for multiple comparisons.

Results: At baseline, mothers were 31.6 (range: 19.9, 41.4) years with mean serum 25(OH)D 66.0±25.3 nmol/L, percentage fat mass was 33.8±5.4 % and android fat mass 217.9±79.7 g. In children at 24-months, mean serum 25(OH)D was above the cut-point for sufficiency of 50 nmol/L and not different between males and females (males: 82.0±17.6 and females: 76.5±14.0 nmol/L, P=0.16). Postpartum maternal serum 25(OH)D was a positive predictor of children’s 25(OH)D concentrations (β= 0.25±0.08 nmol/L, P=0.0031) at 24 months. Similarly, postpartum maternal android fat mass was a positive correlate of children’s android fat mass (β= 0.03±0.01 g, P=0.0201). Maternal gynoid fat mass was not related to children's gynoid fat mass (P=0.76). Overall, female children had higher android and gynoid fat mass compared to male counterparts (P=0.0348).

Conclusions: Maternal android adiposity and maternal serum 25-hydroxyvitamin D are separate important modifiable correlates of children adiposity and vitamin D status at 2 years of age. These findings reinforce the importance of maternal programming of body composition and vitamin D status in children.

Funding Sources: The Canadian Institutes of Health Research