(P17-040-23) Effects of Maternal Vitamin D Supplementation on Maternal and Infant Biomarkers of Environmental Enteric Dysfunction: A Secondary Analysis of a Randomized Controlled Trial

Objectives: Environmental enteric dysfunction (EED) is an acquired, subclinical state of intestinal inflammation common in low- and middle-income countries (LMICs). Although supplementation with vitamin D has purported anti-inflammatory properties, its ability to mitigate biomarkers of EED remains unclear. We sought to examine the effects of maternal vitamin D₃ supplementation on biomarkers of EED, systemic inflammation (SI), and growth in pregnant women living with HIV and their infants in Dar es Salaam, Tanzania.

Methods: We conducted subgroup analyses of mothers (n=719) and infants (n=355 at 6 weeks, n=266 at 6 months) participating in a randomized, triple-blind, placebo-controlled trial of maternal 3,000 IU vitamin D3 supplementation taken daily beginning in the second trimester of pregnancy until 1 year postpartum. Biomarkers of EED [soluble CD14 and intestinal fatty acid-binding protein (I-FABP)], SI [C-reactive protein and alpha-1-acid glycoprotein (AGP)], and growth factors [insulin-like growth factor 1 (IGF-1) and fibroblast growth factor 21] were measured via the Multiple-Micronutrient and Environmental Enteric Dysfunction Assessment Tool (MEEDAT). Anti-flagellin and anti-lipopolysaccharide immunoglobulins were measured via enzyme-linked immunosorbent assay. Comparisons by randomized treatment arm were performed using ordinary least squared regression models with log2-transformed biomarkers.

Results: At 32 weeks gestation, I-FABP (β: -0.19, p = 0.03) and AGP (β: -0.11, p=0.04) were significantly lower in mothers who received vitamin D3 supplementation compared to those who did not. At 6 weeks of age, IGF-1 (β: -0.31, p = 0.03) was significantly lower in infants whose mothers received vitamin D₃ supplementation compared to those who did not. There was no effect on the other EED, SI, or growth markers.

Conclusions: Vitamin D₃ supplementation during pregnancy and postpartum among women living with HIV reduces certain biomarkers of EED and SI. While these benefits do not appear to extend to infants, there may be an effect on infant growth factors.

Funding Sources: The parent trial was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The sub-study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases.