Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case-control study

Vitamin D Deficiency as a Risk Factor of Preeclampsia during Pregnancy

A balanced diet is achieved not only via the consumption of a variety of food products but also by ensuring that we take in sufficient quantities the micronutrients necessary for the adequate functioning of the human body, such as vitamins, an important one of which is vitamin D. Vitamin D has been closely linked to bone health. Vitamin D deficiency has often been associated with negative effects concerning several pregnancy adverse outcomes, the most important of which are the birth of SGA newborns, premature birth, and, finally, preeclampsia, which are discussed in this work. The aim of this review is to critically summarize and scrutinize whether the concentration of vitamin D in the blood serum of pregnant women in all its forms may be correlated with the risk of preeclampsia during pregnancy and whether vitamin D levels could act both as a protective agent or as a risk factor or even a prognostic measure of the disease. The association of vitamin D levels with the onset of preeclampsia was examined by searching the PubMed and Google Scholar databases. A total of 31 clinical trials were identified and included in this review, with the aim of summarizing the recent data concerning vitamin D levels and the risk of preeclampsia. Among them, 16 were published in the last five years, and 13 were published within the last a decade. Most studies showed a significant association between vitamin D deficiency and preeclampsia risk. It was also found that the higher the dose, the lower the risk of disease. Of the 31 articles, only 7 of them did not show a significant difference between vitamin D levels and preeclampsia regardless of comorbidity. The results of this review suggest that there is indeed an association between the concentration of vitamin D during pregnancy and the risk of preeclampsia; however, further studies are strongly recommended to derive conclusive evidence.

Association of maternal vitamin D status with the risk of preeclampsia

The aim of this study was to examine serum vitamin D concentrations from early pregnancy until delivery in women who did and did not develop preeclampsia. This longitudinal study was carried out in Pune, India. A total of 1154 women with singleton pregnancies were recruited in early pregnancy from two hospitals. Blood samples were collected and stored at four time points across gestation: V1 = 11-14 weeks, V2 = 18-22 weeks, V3 = 26-28 weeks and V4 = at delivery. 108 women who developed preeclampsia (PE) and 216 who did not develop PE (Non-PE) were randomly selected from the remainder. Serum 25-hydroxy vitamin D concentrations (25(OH)D) were estimated in their samples using commercially available ELISA kits. Independent t-tests were used to compare 25(OH)D between PE and non-PE groups. Logistic and linear regressions were used to examine associations of 25(OH)D with the risk of preeclampsia and birth outcomes, respectively, after adjusting for confounders. The mean (SD) 25(OH)D at V1 was 21.95 (19.64) in the Non-PE group and 17.76 (13.21) in the PE group. A decrease in the concentrations of vitamin D (ng ml^-1) in mid-pregnancy (V2) and at delivery was associated with an increased risk of preeclampsia (0.31 [95% CI 0.11, 0.86], p = 0.024 and 0.24 [95% CI 0.08, 0.77], p = 0.016), respectively. Our finding of lower vitamin D concentrations in mid-pregnancy, before women developed clinical preeclampsia, suggests that vitamin D may have a role in its pathophysiology.

Dietary intake and serum concentrations of vitamin A and vitamin E and pre-eclampsia risk in Chinese pregnant women: A matched case-control study

Background

Many studies have suggested that the serum concentrations of vitamin A (VA) and vitamin E (VE) influence preeclampsia (PE) risk in pregnant women. However, few studies have assessed whether dietary intake and serum concentrations of VA and VE are correlated with PE risk.

Methods

A 1:1 matched case-control study was conducted to explore the association between the dietary intake and serum concentrations of VA and VE and the risk of PE in pregnant Chinese women. A total of 440 pregnant women with PE and 440 control pregnant women were included in the study. Dietary information was obtained using a 78-item semi-quantitative food frequency questionnaire. Serum concentrations of VA and VE were measured by liquid chromatography-tandem mass spectrometry.

Results

Compared with the lowest quartile, the multivariate-adjusted odds ratios [95% confidence interval (CI)] of the highest quartiles were 0.62 (95% CI: 0.40-0.96, P trend = 0.02) for VA, 0.51 (95% CI: 0.33–0.80, P trend =0.002) for β-carotene, and 0.70 (95% CI: 0.45–1.08, P trend = 0.029) for retinol. Additionally, for serum VA and VE concentrations, the multivariate-adjusted odds ratios (95% CI) were 2.75 (95% CI: 1.24–6.13, P trend = 0.002) and 11.97 (95% CI: 4.01–35.77, P trend < 0.001), respectively. No significant association was seen between VE intake and PE risk.

Conclusions

Dietary VA intake was negatively correlated with PE risk, and serum VA and VE concentrations were positively correlated with PE risk among pregnant Chinese women.

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.