Vitamin D deficiency associated with higher maternal and cord blood lipid and ketone levelsVitamin D deficiency linked to higher lipid levels in pregnancy

INTRODUCTION: Vitamin D (vitD) plays a role in metabolic regulation, including lipid metabolism and insulin sensitivity. During pregnancy, profound physiological changes in lipid handling and ketogenesis occur to support fetal development. However, the extent to which maternal vitamin D status influences these metabolic adaptations and fetal metabolic markers remains unclear. METHODS: In this secondary analysis, we examined lipid distribution throughout pregnancy-from before 20 weeks' gestation to delivery-in women with overweight or obesity, stratified by vitamin D status (deficiency, insufficiency, or sufficiency), assessing both maternal and cord blood. Main inclusion criteria were: age > =18 years, singleton pregnancy, < 20 weeks' gestation, BMI ≥ 29 kg/m. Women with GDM < 20 weeks' gestation were excluded. In total, 962 pregnant women were divided into vitD deficient (< 30 nmol/L, n = 102), insufficient (30-50 nmol/L, n = 222) and sufficient (> 50 nmol/L, n = 638) groups. VitD levels and lipid concentrations were assessed at < 20, 24-28 and 35-37 weeks' gestation and in cord blood. RESULTS: Compared with vitD sufficient women, women with vitD deficiency had significantly larger increases in LDL-C throughout pregnancy and ß-OH-butyrate at 24-28 weeks' gestation, in adjusted analysis. VitD in cord blood was highest in offspring of mothers with vitD sufficiency. In cord blood, significantly higher ß-OH-butyrate was observed with vitD deficiency; lipid concentrations were similar between groups. CONCLUSIONS: Early vitamin D deficiency before 20 weeks of gestation was associated with altered metabolic trajectories during pregnancy, including greater increases in LDL cholesterol and ketone body concentrations in women with overweight or obesity, as well as higher cord blood ketone levels in their offspring. These findings suggest that early maternal vitamin D status may influence maternal and fetal metabolic adaptations, although causal relationships and clinical implications require further investigation. TRIAL REGISTRATION: Trial registered at ISRCTN registry (https://doi.org/10.1186/ISRCTN70595832) trial number ISRCTN70595832. Registration date 02/12/2011.