Preventing Health Disparities during Pregnancy through Vitamin D (VitD) Supplementation: Preliminary Results of a Randomized Controlled Trial

Abstract

BackgroundVitD deficiency is associated with adverse pregnancy outcomes in certain populations, particularly preeclampsia and preterm birth. The association of adverse outcomes in a diverse group of healthy women was previously linked to circulating 25(OH)D but not treatment due to a high rate of nonadherence.ObjectiveIn a group of healthy women adherent to treatment using a gummy formulation, determine if higher dose vitD supplementation (4400 IU/day) was effective in reducing comordibities of pregnancy compared with a control group (400 IU/day).Design/MethodsIn 2012–2015, 257 healthy women living in Charleston, SC were randomized to receive 1 of 2 vitD daily regimens (400 vs 4400 IU VitaFusion gummies) beginning at 8–12 weeks' gestation until delivery. Circulating 25OHD and urinary calcium/creatinine (Ca/Cr) ratio were measured monthly. Utilizing standardized questionnaires, maternal and fetal health status were assessed monthly. The following comorbidities of pregnancy were collected for each maternal/fetal/neonatal pair: hypertension (HTN), diabetes, preeclampsia, preterm delivery, chorioamnionitis, miscarriage, intrauterine fetal death or bacterial vaginosis (BV). Data were analyzed using R (Vienna, Austria).ResultsThe groups had similar baseline characteristics (Table 1). By the 2nd month, 25OHD remained statistically significantly higher in the 4400 IU group compared to the 400 IU group through delivery (p<0.001). BV at months 4 and 7 was the most common pregnancy morbidity among African Americans (25.7% and 14.9%, respectively) and Hispanics (13.4% and 14.6%); whereas among Caucasians, diabetes (6%) and chorioamnionitis (6%) were the most common. No differences in serum calcium and urinary Ca/Cr ratios between groups were noted. After adjusting for effect of age, BMI, ethnicity, 25(OH)D at baseline or prior to delivery, higher dose vitD supplementation (4400IU) was not associated with any single pregnancy morbidity (HTN, diabetes, preeclampsia, preterm delivery, chorioamnionitis, miscarriage, intrauterine fetal death or BV); however, the higher dose was associated with lower risk of combined pregnancy comorbidities among African Americans (OR=0.26, p=0.034) but not Hispanics and Caucasians.Conclusion(sVitD supplementation impacted African American women and their pregnancy outcomes and may explain the higher rates of adverse events during pregnancy in this group. Such findings may inform future public health policy surrounding pregnancy interventions for these most at‐risk women.Support or Funding InformationW. K. Kellogg Foundation and the South Carolina Clinical & Translational Research (SCTR) Institute, with an academic home at the Medical University of South Carolina, NIH/NCATS UL1 RR029882 and UL1 TR000062. Maternal Characteristics and Vitamin D Status and Safety Parameters by Treatment Group Maternal Characteristic 400 IU Group (N=120) 4400 IU Group (N=137) p‐value Maternal Age, years (Mean ± SD) 28.7 ± 5.1 28.9 ± 4.6 0.74 Maternal Race/Ethnicity, N (%) 0.57 African American 34 (45.9%) 40 (54.1%) Hispanic 42 (51.2%) 40 (48.8%) Caucasian 44 (43.6%) 57 (56.4%) Maternal Baseline 25(OH)D, ng/mL (Mean ± SD) 26.9 ± 10.4 26.0 ± 9.1 0.49 Maternal 25(OH)D one month prior to delivery, ng/mL (Mean ± SD) 34.4 ± 13.7 51.9 ± 18.5 <0.001