Figure 2. Dose-response association between maternal serum 25OHD concentrations at 10 to 18 weeks of gestation and the corresponding predicted probability of preeclampsia derived from a logistic regression model adjusted for the identified confounders (Table 2).

The gray zone indicates 0.95 confidence bands (N_preeclampsia= 67, N_healthy = 749). The minimum predicted risk for the population under study relative to the distribution of pregnant women (vertical tick marks on the x axis) falls at the concentrations of 40 to 50 ng/ml serum vitamin D.