Plasma 25-Hydroxyvitamin D and Severe Pre-Eclampsia in a Population With Profound Vitamin D Deficiency

Abstract

<strong>Background:</strong> There is biologic and clinical evidence that links vitamin D deficiency to pre-eclampsia. The Vitamin D receptor is present in the placenta, cardiovascular system, and lymphocytes. It has anti-inflammatory, immune regulatory, and anti-hypertensive properties and facilitates placental implantation. Each of these processes is involved in the pathogenesis of pre-eclampsia. <strong>Objectives:</strong> The main purpose of this study was to study the relationship between vitamin D deficiency and severe pre-eclampsia in a population residing in southern Iran that is generally known to have a high prevalence of vitamin deficiency. As a second objective, the prevalence of vitamin D deficiency in pregnant women was investigated. <strong>Patients and Methods:</strong> We conducted a case-control study of 59 patients with severe preeclampsia and 217 controls, all of whom were from southern Iran. Cases and controls were matched for age, body mass index, and gestational age. The study was carried out in autumn and winter. Plasma 25-hydroxyvitamin D was measured using high performance liquid chromatography, and the results were compared between the two groups. <strong>Results:</strong> Almost all controls and patients had 25-hydroxyvitamin D levels below normal, and 69% had levels below 10 ng/mL. The mean 25-hydroxyvitamin D levels in the patient and control groups were 8.4 (6.2) and 8.5 (6.9) ng/ml (P = 0.80), respectively. The level of 25-hydroxyvitamin D had no significant association with subjects' body mass index or age. <strong>Conclusions:</strong> Pregnant women in our region have a high prevalence of vitamin D deficiency, and in a population with severe vitamin D deficiency, there is no significant correlation between 25-hydroxyvitamin D levels and preeclampsia. Severe deficiency masks any possible association in a case-control study. Controlled trials with vitamin D supplementation are recommended for further studies.