Vitamin D Status in Preeclamptic and Non-preeclamptic Pregnant Women: A Case-Control Study in the North West of Iran

Vitamin D and preeclampsia: A systematic review and meta-analysis

Objectives

Preeclampsia is one of the most frequent pregnancy disorders, with a global incidence of 2%-8%. Serum 25-hydroxyvitamin D is an essential mineral for human health; some studies suggest link between 25-hydroxyvitamin D deficiency and preeclampsia, while others offer contradictory findings. Thus, the goal of this study is to evaluate the relationships between maternal 25- hydroxyvitamin D concentrations and the risk of preeclampsia. In addition to this, our study also evaluates the effects of 25- hydroxyvitamin D supplementation on the incidence of preeclampsia. Therefore, assessing 25- hydroxyvitamin D's potential as a possible intervention to lower the risk of preeclampsia.

Methods

The Medline database was queried from inception until July 2021 for randomized controlled trials and observational studies without any restrictions. The studies assessing the association between 25-hydroxyvitamin D deficiency and preeclampsia and the impact of 25-hydroxyvitamin D supplementation on the incidence of preeclampsia were incorporated. The results were reported using a random-effects meta-analysis and the Mantel-Haenszel odds ratio. A p-value of <0.05 was considered significant for the analysis.

Results

This analysis includes 34 papers, including 10 randomized controlled trials and 24 observational studies. According to our pooled analysis, 25-hydroxyvitamin D supplementation was significantly associated with a lower risk of preeclampsia in pregnant women (OR: 0.50; 95% CI: 0.40-0.63; p = 0.00001), while 25-hydroxyvitamin D deficiency was significantly associated with an increased risk of preeclampsia (OR: 4.30; 95 % CI: 2.57-7.18; p < 0.00001, OR: 1.71; 95 % Cl: 1.27-2.32; p = 0.0005, OR 1.61; 95 % Cl: 1.21-2.16; p = 0.001).

Conclusion

Results suggest that 25-hydroxyvitamin D has a significant relationship with preeclampsia as confirmed by the findings that low maternal 25-hydroxyvitamin D concentrations cause increased risk of preeclampsia while 25-hydroxyvitamin D supplementation reduces the incidence of preeclampsia. Our findings indicate that 25-hydroxyvitamin D supplementation can be used as a possible intervention strategy in preventing one of the most common causes of maternal mortality around the world, preeclampsia.

Review: Influence of 25(OH)D Blood Concentration and Supplementation during Pregnancy on Preeclampsia Development and Neonatal Outcomes

Briefly, 25-hydroxyvitamin D (25(OH)D) plays an essential role in embryogenesis and the course of intra- and postnatal periods and is crucially involved in the functioning of the mother-placenta-fetus system. The low quantity of 25(OH)D during pregnancy can lead to an elevated risk for preeclampsia occurrence. Despite the numerous studies on the association of 25(OH)D deficiency and preeclampsia development, the current research on this theme is contradictory. In this review, we summarize and analyze study data on the effects of 25(OH)D deficiency and supplementation on pregnancy, labor, and fetal and neonatal outcomes.

Evaluating the association between maternal vitamin D deficiency and preeclampsia among Indian gravidas

OBJECTIVE

The association between vitamin D deficiency and devastating preeclampsia is still debated. In this present study, our aim is to evaluate whether a statistically significant association exists between vitamin D deficiency and preeclampsia in Indian gravidas. As to the best of our knowledge, no study of this context with such a large sample size is done in the Indian population till now.

METHOD

A case-control study was performed in the year 2015-2019 where we enrolled 1000 pregnant women with preeclampsia admitted either in labor or for induction of labor in the study group and 1000 pregnant women without preeclampsia either in labor or admitted for induction of labor at term gestation in the control group. Serum 25-hydroxyvitamin D [25 (OH)] D levels of both the groups were measured through the radioimmunoassay method and analyzed. In both the groups, samples were collected equally across all the seasons of the year to avoid confounding by seasonal variation of vitamin D. Primary outcome measures the association of vitamin D deficiency and preeclampsia. While secondary outcome measures the correlation between levels of vitamin D deficiency with the severity of preeclampsia.

RESULT

A significantly low mean vitamin D level was seen in preeclamptic women (11.0 ± 7.1 ng /ml) compared to normotensive (31.4 ± 1.7 ng/ml) with p < .001. We observed approximately 11 fold increased odds of having preeclampsia in vitamin D deficient women (OR: 11.308; 95 % CI 7.5982-14.0097). Moreover, we observed that as vitamin D level decreases, the severity of preeclampsia increases (p < .001).

CONCLUSION

Compared with normotensive women, preeclamptic women had a significantly low level of vitamin D, suggesting a significant association between vitamin D deficiency and preeclampsia.

Prevalence of vitamin D deficiency in Egyptian patients with pregnancy-induced hypertension

Background Hypertensive disorders of pregnancy can cause severe maternal and fetal acute morbidity and mortality. Women with pre-eclampsia have been found to have alterations in calcium and vitamin D metabolism. There are conflicting results regarding the role of vitamin D deficiency in the development of pre-eclampsia. The aim was to compare 25 (OH) D level in patients with pre-eclampsia, eclampsia and normotensive pregnant women as well as to study the prevalence of Vitamin D deficiency among the 3 groups. Patients and methods Two hundred patients with pre-eclampsia, 100 with eclampsia and 200 normotensive pregnant controls were compared as regards vitamin D level. Results Mean 25(OH)D level was lower in the pre-eclampsia (14.8 ± 5.4 ng/mL) and in the eclampsia group (10.5 ± 1.6 ng/mL) than in the pregnant controls (19.5 ± 6.5 ng/mL) (P = 0.002). This difference was only significant between the eclampsia group and the pregnant controls (P = 0.02). All eclampsia cases had vitamin D insufficiency as compared to 17.5% in the pre-eclampsia group and 39.5% in the control group. Deficiency of vitamin D (<12 ng/mL) was 47.5% in the pre-eclampsia group, 80% in the eclampsia group and only 10.5% in the control group (P = 0.035). Conclusion Vitamin D deficiency is highly prevalent among Egyptian pregnant females. Our study supports the hypothesis that low vitamin D level can play a role in the development of pre-eclampsia and eclampsia. Thus, supplementation might prevent or delay the development of pre-eclampsia and eclampsia especially in patients at a high risk.

Evaluation of vitamin D status, parathyroid hormone, and calcium among Iranian pregnant women with preeclampsia: A case-control study

BACKGROUND

Preeclampsia is considered as a serious life-threatening condition that could affect both maternal and fetal outcome. Many studies have examined the association of nutritional factors with the incidence of preeclampsia. However, little is known about the possible role of vitamin D in the development of preeclampsia among the Iranian population.

OBJECTIVE

The aim of the present study was to evaluate the association between vitamin D status and preeclampsia.

MATERIALS AND METHODS

A total of 120 pregnant women who were referred to Kamali and Alborz General Hospital located in the Karaj City were enrolled in this study and categorized into preeclamptic and control groups (n = 60/each). The clinical details of patients such as demographic characteristics and laboratory findings were obtained from the patients. The serum levels of vitamin D, calcium, phosphorus, and parathormone were also measured. Multivariate logistic regression analysis was used to assess for independent predictors of preeclampsia.

RESULTS

The mean age among pregnant women with preeclampsia and control group were 31.48 ± 5.25 and 29.01 ± 5.28, respectively. The mean body mass index among the preeclamptic group was 27.92 ± 4.98, which was significantly higher compared to the control group (p < 0.001). The serum vitamin D levels were significantly lower in women with preeclampsia compared to the control subjects (p = 0.007). Moreover, no correlation between vitamin D deficiency and predisposing factors of preeclampsia was observed after adjusting for confounding factors.

CONCLUSION

Our study revealed that serum vitamin D level is significantly lower in among the pregnant women diagnosed with preeclampsia compared to the healthy subjects. However, no correlation was observed between the vitamin D status and the risk of preeclampsia development.

Vitamin D and its impact on maternal-fetal outcomes in pregnancy: A critical review

The role of vitamin D beyond its classical function in calcium homeostasis has been of significant interest in recent years. There has been expanding research on the pleiotropic role of vitamin D in pregnancy and the implications of its deficiency on maternal-fetal outcomes. Several studies have associated low maternal vitamin D status to adverse outcomes in pregnancy, including preeclampsia, gestational diabetes, preterm births, low birth weight, and others. Several randomized controlled clinical trials of Vitamin D supplementation during pregnancy have also been conducted. Though some of the studies found improvement in pregnancy outcomes with vitamin D supplementation, others have not shown any association. In this article, we have critically reviewed the observational and interventional studies, published primarily within the past two years (January 2014 to February 2016) on the influence of vitamin D deficiency on pregnancy and the impact of its supplementation. The potential underlying mechanisms of vitamin D in regulating each of the outcomes have also been discussed.

The dietary composition of women who delivered preterm and full-term infants

OBJECTIVES

Literature data show that excess and primary deficiency in particular nutrients, vitamins and minerals may lead to pre-eclampsia, gestational diabetes, hypertension and neural tube defects in the foetus. The aim of the study was to determine differences in average daily consumption of selected nutrients during pregnancy in women who did not supplement their diet and to evaluate the influence of dietary habits on the occurrence of pre-term delivery and hypertension in pregnant women.

SAMPLE GROUP AND METHODS

Information on the course of pregnancy and the newborn's health status at birth was derived from the Charter of Pregnancy and documents recorded by the hospital. Women's eating habits and dietary composition were analyzed on the basis of a dietary questionnaire. The sample group was divided into four groups: women who delivered neonates appropriate for gestational age (AGA), women with gestosis who delivered AGA neonates by means of caesarean sections, women who delivered pre-term neonates (PTB) and women with gestosis who delivered PTB by means of caesarean sections.

RESULTS

In the case of women with vaginal delivery at term the average intake of iodine was always higher than in other groups. Analysis of average daily intake of folates revealed a higher intake in the group of women who gave birth to full-term neonates with proper neonatal weight in comparison with the groups of women with pre-term delivery. P≤0.05.

CONCLUSIONS

Statistically significant differences in average daily intake of folates, iodine, retinol, magnesium and iron were observed between the group of women with vaginal delivery at term and the groups of women with diagnosed hypertension who delivered preterm. Correlation was demonstrated between average daily intake of iodine and vitamin D and the occurrence of arterial hypertension. Supplementation of the diet of women in the preconception and prenatal period with minerals and vitamins should be considered.