The High Prevalence of Vitamin D Insufficiency in Cord Blood in Calgary, Alberta (APrON-D Study).

Objective: Vitamin D is important in promoting healthy pregnancy and fetal development. We undertook this study to measure 25-hydroxyvitamin D in maternal and cord blood and to identify maternal factors related to vitamin D status in Calgary.

Methods: Blood samples collected at the time of delivery from the Alberta Pregnancy Outcomes and Nutrition study cohort (ApronStudy.ca) participants were processed for plasma and assayed using liquid chromatography mass spectrometry methodology for 25(OH)D.

Results: Ninety-two pairs of maternal and cord blood samples were obtained. The prevalence of 25(OH)D insufficiency-25(OH)D <75 nmol/L-was 38% and 80% in women and neonates, respectively. Vitamin D supplementation was the only clinical factor associated with 25(OH)D sufficiency, and the odds of sufficiency were 3.75 (95% CI 1.00 to 14.07) higher for women and 5.27 (95% CI 1.37 to 20.27) when over 2000 IU/day were used.

Conclusion: Using liquid chromatography mass spectrometry, we demonstrated a very high prevalence of vitamin D insufficiency in cord blood and that the use of high dose vitamin D was associated with greater odds of sufficiency in pregnant women and cord blood in Alberta.