Vitamin D Status of Mothers and Their Neonates in North Texas

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 238-262-Vitamin D Action, Deficiency & Disorders
Bench to Bedside
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-247
Teena Thomas*1, Chloe Rushing1, James Alexander1, Perrin C White1 and Soumya Adhikari2
1UT Southwestern Medical Center, Dallas, TX, 2UT Southwestern Med Cntr, Dallas, TX
BACKGROUND:  A high degree of variability has been reported in the prevalence of Vitamin D insufficiency and deficiency in pregnancy, varying with geography and ethnicity, and comparatively little data exist on Hispanic women. Recent neonatal data suggest a high prevalence of maternal vitamin D insufficiency in the largely Hispanic population who deliver at Parkland Memorial Hospital (PMH) in Dallas, TX1

OBJECTIVES:  To determine the prevalence of vitamin D insufficiency and deficiency in a predominantly Hispanic population of mothers and their neonates born at PMH and the maternal and neonatal characteristics correlated with higher risks of insufficiency and deficiency.   We hypothesized a prevalence of vitamin D insufficiency of 75% and that pre-pregnancy BMI would be inversely correlated with maternal 25-hydroxyvitamin D (25-OHD) levels at delivery.

METHODS:  We determined paired maternal and umbilical cord 25-OHD levels (tandem mass spectrometry) at delivery in women who delivered term singleton neonates from March 2012 - January 2013. We collected data regarding participants’ diet, lifestyle and maternal, neonatal & delivery characteristics to evaluate for associations with vitamin D insufficiency.  

RESULTS:  Of 289 women to be enrolled, 170 have been enrolled to date with anticipated study enrollment and statistical analysis to be complete in May 2013.  Fifty-nine percent of the women to date were Hispanic and 35% were African-American.  Median (interquartile range (IQR)) maternal serum 25-OHD was 29 (22-44) ng/mL and median (IQR) cord blood 25-OHD was 18 (14-23) ng/mL.  Approximately 51% of maternal and 91% of cord blood serum were vitamin D insufficient (25-OHD levels < 30 ng/mL).  Maternal and cord blood 25-OHD levels were strongly correlated (r = 0.86).

Median (IQR) maternal 25-OHD levels were 37 (26-47) ng/mL in the summer and 25 (19-31) ng/mL in the fall. Median (IQR) cord blood levels in the summer and fall were 23 (16-27) and 15 (11-19) ng/mL respectively. 

Of the 91 women who took prenatal vitamins during pregnancy, the median (IQR) maternal & cord blood 25-OHD were 35 (27-47) and 20 (15-27) ng/mL vs. 26 (19-35) and 16 (12-22) ng/mL in the 79 women who did not.  Of 119 women who reported sun exposure during their pregnancy, the median (IQR) maternal and cord 25-OHD were 32 (23-44) ng/mL and 18 (14-26) ng/mL vs. 26 (22-35) ng/mL and 15 (13-25) ng/mL in the 51 women who did not.

Median (IQR) 25-OHD levels in both maternal serum and cord blood varied little with maternal body mass index (BMI): normal BMI to overweight to obese: maternal 29 (22-43) to 30 (23-44) to 31 (23-45) ng/mL; and cord, 18 (14-26) to 18 (14-24) to 18 (14-23) ng/mL.

CONCLUSION:  Vitamin D insufficiency is common in maternal and cord blood in this predominantly Hispanic population.  Maternal and cord blood vitamin D levels appear to differ according to season and prenatal vitamin use but not with self-reported sun exposure or maternal BMI.

(1)  Thomas, T.C., et al., Transient neonatal hypocalcemia: presentation and outcomes. Pediatrics, 2012. 129(6): p. e1461-7.

Nothing to Disclose: TT, CR, JA, PCW, SA

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Supported by the Children’s Medical Center Foundation.