The Relationship between Vitamin D Levels in Pregnancy and Blood Glucose at the Gestational Diabetes Screening

Monday, 9 November 2015: 3:55 PM

Jeanine L. Senti, MSN, BSN, APRN-BC, IBCLC, CNS
Family Birthing Center, Altru Health System, Grand Forks, ND, USA

Hyperglycemia during pregnancy is associated with adverse maternal and fetal outcomes so interventions which can reduce this harm are needed. Hypovitaminosis-D has been associated with impaired glucose metabolism in the non-pregnant population but there are conflicting results on the effect of vitamin D on glucose metabolism in pregnancy.  The key research question is if vitamin D influences glucose homeostasis in pregnancy when controlling for the known confounding variables of body mass index (BMI) and maternal age.  This prospective study used a convenience sample of 52 nulliparous women.  Serum vitamin D levels were obtained through laboratory measures at three predetermined points during pregnancy. The medical record was utilized to obtain the blood glucose result from the routine gestational diabetes screening, BMI, and demographic information.  Eighty-five percent of the participants had hypovitaminosis-D during pregnancy and vitamin D levels did not statistically improve even though all reported taking a daily prenatal vitamin with the recommended amount of vitamin D.  There was no evidence of a statistically significant relationship between vitamin D levels at any of the three points and the blood glucose levels when controlling for the known confounding variables of BMI and age (R square .084, .071, and .075 respectively).  However, the high percentage of hypovitaminosis-D resulted in inadequate variance in this sample to show the differences.  There was a statistically significant correlation among the three vitamin D levels (p=0.01).  There was a statistically significant relationship between BMI and the first (p=0.05) and second (p=0.05) vitamin D levels.  The findings suggest that 1) the amount of vitamin D in prenatal vitamins is inadequate to improve serum vitamin D levels during pregnancy, 2) women with a higher BMI need additional vitamin D during pregnancy, and 3) there is a need for further research on this topic.