Association between maternal mid-gestation vitamin D status and neonatal abdominal adiposity

Objectives Lower vitamin D status has been associated with adiposity in children through adults. However, the evidence of the impact of maternal vitamin-D status during pregnancy on offspring's adiposity is mixed. The objective of this study was to examine the associations between maternal vitamin-D [25(OH) D] status at mid-gestation and neonatal abdominal adipose tissue (AAT) compartments, particularly the deep subcutaneous adipose tissue linked with metabolic risk. Methods Participants (N = 292) were Asian mother-neonate pairs from the mother-offspring cohort, Growing Up in Singapore Towards healthy Outcomes. Neonates born at >= 34 weeks gestation with birth weight >= 2000 g had magnetic resonance imaging (MRI) within 2-weeks post-delivery. Maternal plasma glucose using an oral glucose tolerance test and 25(OH) D concentrations were measured. 25(OH) D status was categorized into inadequate (<= 75.0 nmol/L) and sufficient (> 75.0 nmol/L) groups. Neonatal AAT was classified into superficial (sSAT), deep subcutaneous (dSAT), and internal (IAT) adipose tissue compartments. Results Inverse linear correlations were observed between maternal 25(OH) D and both sSAT (r = -0.190, P = 0.001) and dSAT (r = -0.206, P < 0.001). Each 1 nmol/L increase in 25(OH) D was significantly associated with reductions in sSAT (beta = -0.14 (95% CI: -0.24, -0.04) ml, P = 0.006) and dSAT (beta = -0.04 (-0.06, -0.01) ml, P = 0.006). Compared to neonates of mothers with 25(OH) D sufficiency, neonates with maternal 25(OH) D inadequacy had higher sSAT (7.3 (2.1, 12.4) ml, P = 0.006), and dSAT (2.0 (0.6, 3.4) ml, P = 0.005) volumes, despite similar birth weight. In the subset of mothers without gestational diabetes, neonatal dSAT was also greater (1.7 (0.3, 3.1) ml, P = 0.019) in neonates with maternal 25 (OH)-inadequacy. The associations with sSAT and dSAT persisted even after accounting for maternal glycemia (fasting and 2-h plasma glucose). Conclusions Neonates of Asian mothers with mid-gestation 25(OH) D inadequacy have a higher abdominal subcutaneous adipose tissue volume, especially dSAT (which is metabolically similar to visceral adipose tissue in adults), even after accounting for maternal glucose levels in pregnancy.