Calcium and Vitamin D Supplementation for Prevention of Preeclampsia: A Systematic Review and Network Meta-Analysis
What this study found
Overall, calcium supplementation reduced preeclampsia risk and vitamin D also showed a possible benefit, although the vitamin D evidence was less certain. In direct meta-analysis, preeclampsia risk was lower with calcium versus placebo (RR 0.54, 95% CI 0.41 to 0.70), vitamin D versus placebo (RR 0.47, 95% CI 0.24 to 0.89), and calcium plus vitamin D versus placebo (RR 0.50, 95% CI 0.32 to 0.78). Network meta-analysis showed a similar pattern for calcium (RR 0.49, 95% CI 0.35 to 0.69), while vitamin D (RR 0.43, 95% CI 0.17 to 1.11) and calcium plus vitamin D (RR 0.57, 95% CI 0.30 to 1.10)…
- Study & population
- Systematic review and network meta-analysis of randomized controlled trials in pregnant women, including both low-risk and high-risk pregnancies from multiple countries.
- Intervention
- This systematic review evaluated calcium supplementation, vitamin D supplementation, and calcium plus vitamin D during pregnancy, each compared with placebo or control.
- Key limitation
- The vitamin D and calcium plus vitamin D estimates were based on few trials and were less precise than calcium alone.
View source
Open PDFOriginal abstract
Vitamin D supplementation effects with or without calcium in pregnancy for reducing risk of preeclampsia and gestational or pregnancy induced hypertension are controversial. Literature was systematically searched in Medline, Scopus and Cochrane databases from inception to July 2017. Only randomized controlled trials (RCTs) in English were selected if they had any pair of interventions (calcium, vitamin D, both, or placebo). Systematic review with two-step network-meta-analysis was used to indirectly estimate supplementary effects. Twenty-seven RCTs with 28,000 women were eligible. A direct meta-analysis suggested that calcium, vitamin D, and calcium plus vitamin D could lower risk of preeclampsia when compared to placebo with the pooled risk ratios (RRs) of 0.54 (0.41, 0.70), 0.47 (0.24, 0.89) and 0.50 (0.32, 0.78), respectively. Results of network meta-analysis were similar with the corresponding RRs of 0.49 (0.35, 0.69), 0.43 (0.17, 1.11), and 0.57 (0.30, 1.10), respectively. None of the controls were significant. Efficacy of supplementation, which was ranked by surface under cumulative ranking probabilities, were: vitamin D (47.4%), calcium (31.6%) and calcium plus vitamin D (19.6%), respectively. Calcium supplementation may be used for prevention for preeclampsia. Vitamin D might also worked well but further large scale RCTs are warranted to confirm our findings.