Serum 25-hydroxyvitamin D levels throughout pregnancy: a longitudinal study in healthy and preeclamptic pregnant women.

Background: Worldwide there is a high prevalence of 25-hydroxyvitamin D (25OHD) deficiency and has been associated with adverse outcomes during pregnancy.

Objective: This is a nested, case-control study in a longitudinal cohort to compare the serum 25OHD levels and other biomarkers throughout pregnancy in a group of 20 preeclamptic women and 61 healthy pregnant women. An additional group of 29 healthy non-pregnant women were also studied during the two phases of the menstrual cycle.