[1665.6] Vitamin D Supplementation during Pregnancy Part 2 NICHD/CTSA Randomized Clinical Trial (RCT): Outcomes

Carol L. Wagner, Donna Johnson, Thomas C. Hulsey, Myla Ebeling, Judy Shary, Pamela G. Smith, Betty Bivens, Bruce W. Hollis. Pediatrics/Obstetrics, Medical University of SC, Charleston, SC.

BACKGROUND: Vitamin D (vitD) deficiency during pregnancy is a serious public health issue, affecting mother and fetus. Establishing optimal vitD requirements of pregnant women is vital in preventing vitD deficiency and its health-associated comorbidities.
OBJECTIVE: Evaluate the effectiveness of high dose vitD supplementation in decreasing pregnancy comorbidity risks.
DESIGN/METHODS: Following their consent, pregnant women 12-16 wks' gestation were randomized into 1 of 3 tx grps stratified by race: 400, 2000 or 4000 IU vitD₃/day until delivery. Women were evaluated for safety (Abstr#750939), efficacy and effectiveness with monthly 25(OH)D; 1,25(OH)₂D; serum Ca, Cr, phos, and urinary Ca/Cr levels, all measured using standardized methodology. Comorbidities of pregnancy (preeclampsia, gest diabetes, any infection, preterm labor (PTL)/preterm birth (PTB)<37 wks GA) were recorded prospectively for each subject. Investigators and health team were blinded to tx grp.
RESULTS: Of the 494 women who enrolled in the study, 350 women continued until delivery: 98 African American (AA), 137 Hispanic (Hisp) and 115 Caucasian (Cauc) women; with 111 controls, 122 in 2000 IU and 117 in 4000 IU groups. There were no differences in baseline vitD status between dose groups. The mean 25(OH)D by dose group at delivery, as chronic level, and 1-month before delivery were significantly different between control and 2000, control and 4000, and 2000 vs. 4000 (p<0.0001). 25(OH)D had a direct influence on 1,25(OH)₂D levels throughout pregnancy (p<0.0001) with 25(OH)D of 40 ng/mL required to obtain maximum 1,25(OH)₂D production. In bivariate analyses controlling for race, PTL/PTB and infection were inversely related to 25(OH)D and were lowest in the 4000 IU grp (p<0.0001). In logistic regression, comparing 400 vs. 4000 IU and controlling for race, the risk of comorbidities were 0.50 (CI 0.27-0.95; p=0.03) among those in the 4000 IU grp. Using least sq means, when adjusting for race, 25(OH)D of women with comorbidities was 33.4 ng/mL compared to 39.0 ng/mL in those women without (p<0.008).
CONCLUSIONS: VitD sufficiency was strongly associated with decreased risk for PTL/PTB and infection during pregnancy and comorbities of pregnancy, with the greatest effect with 4000 IU vitamin D/day regimen. Therefore, to attain a minimal 25(OH)D level of 40 ng/mL, we recommend 4000 IU/day for all pregnant women.
E-PAS20101665.6

Date: Saturday, May 1, 2010
Platform Session: Neonatal Fetal Nutrition & Metabolism I (2:45 PM - 4:45 PM)
Presentation Time: 4:00 PM
Room: West Ballroom C - Vancouver Convention Centre
Course Number: 1665