Association between serum hypovitaminosis D and preeclampsia: A nested case-control study

Background: Preeclampsia is a major complication of pregnancy and a major cause of perinatal and maternal morbidity and mortality. Vitamin D deficiency has been implicated in the aetiology and pathophysiology of preeclampsia. However, there is no uniformity in the findings of previous studies on the association between vitamin D and preeclampsia.

Aims and Objectives: The study is aimed at determining the association between preeclampsia and maternal vitamin D deficiency.

Materials and Methods: This nested case-control study was conducted among 158 pregnant women (78 preeclamptic women and 80 controls) with singleton pregnancies. Case participants were women with preeclampsia. The controls were matched pregnant women without preeclampsia. Their serum vitamin D levels were determined.

Statistics: Continuous data was analysed using T-test. The statistical significance was inferred at p- value ≤0.05.

Results: The prevalence of hypovitaminosis D in our study was 7.0% overall. The proportion of women with hypovitaminosis D was not significantly different between preeclampsia group and control group (7.7% vs 6.3% respectively; p=0.76). The mean serum concentration of vitamin D in the preeclamptic group was lower than that in the control group, however, the difference was not statistically significant (118.8±17.4nmol/L vs 129.0±19.7nmol/L, p=0.17). There was a weak association between gestational age and the level of serum vitamin D in both groups (r= 0.062 and r= -0.13 respectively).

Conclusions: Hypovitaminosis D is not significantly associated with preeclampsia when compared with control. However, there was a weak association between gestational age and the level of serum vitamin D in both groups.