Association between calcium supplementation and gestational hypertension, and preeclampsia: A Meta-analysis of 26 randomized controlled trials.

BACKGROUND: Pre-eclampsia and eclampsia are common causes of morbidity and mortality, especially in low-income countries. Reducing adverse outcomes associated with hypertensive disorders of pregnancy has been the ultimate priority in recent years. We aim to evaluate the association between calcium supplementation and preeclampsia and gestational hypertension risk among pregnant women. METHODS: A systematic literature search was performed in electronic databases from inception to 15th July 2023, including only randomized controlled trials. Odds ratio (OR) were, and their corresponding 95% confidence interval (95% CI). RESULTS: A total of 26 studies with 20,038 patients (10,003 patients with calcium supplements and 10,035 patients with placebo group) were included in the analysis. The Pooled analysis of primary outcome shows that calcium supplements reduce the risk of preeclampsia by 49% (OR, 0.51(95%CI: 0.40-0.66), P<0.001), and reduce the risk of gestational hypertension by 30% (OR, 0.70 (95%CI: 0.58-0.85)), P<0.001) compared to placebo. There was a trend of lower incidence of preterm delivery (OR, 0.88 (95%CI: 0.71-1.09), P=0.23), labor induction (OR, 0.90 (95%CI: 0.78-1.03), P=0.13), small for gestational age (OR, 0.70 (95% CI:0.37-1.32), P = 0.27), low birth weight (OR, 0.96 (95%CI: 0.86-1.08), P=0.53), perinatal mortality (OR, 0.88 (95%CI: 0.72-1.09), P=0.24), and maternal mortality (OR, 0.48 (95%CI: 0.12-1.84), P=0.28) among calcium supplementation group compared with the placebo group, however, statistical signifance was not achieved. CONCLUSION: This study shows that calcium supplements are associated with a significant reduction in the risk of preeclampsia and gestational hypertension and a trend toward better maternal and fetal-related outcomes.

Hypovitaminosis D and cardiovascular outcomes: A systematic review and meta-analysis.

Background: The relation between blood vitamin D levels and the risk of cardiovascular outcomes is debatable. To our knowledge this is the first comparative meta-analysis of more than 100,000 patients' data with the aim to inspect the relevance of low vitamin D levels with adverse cardiovascular events. Methods: Online databases including PubMed, Embase and Cochrane Central were queried to compare the cardiovascular outcomes among hypovitaminosis D (HVD) and control group. The outcomes assessed included differences in major adverse cardiovascular events (MACE), mortality, myocardial infarction, and heart failure. Unadjusted odds ratios (OR) were calculated using a random-effect model with a 95% confidence interval (CI) and P less than 0.05 as a statistical significance. Results: A total of 8 studies including 426,039 patients were included in this analysis. HVD group was associated with a higher incidence of MACE (OR 1.92, 95% CI 1.24 to 2.98, p = 0.003), while there was no significant association of HVD and all-cause mortality (OR 1.77, 95% CI 0.75 to 4.17, p = 0.19), risk of myocardial infarction (OR 0.69, 95% CI 0.39 to 1.24, p = 0.22), and heart failure (OR 1.20, 95% CI 0.34 to 4.25, p = 0.78). Conclusions: This meta-analysis suggested that low blood levels of vitamin D are associated with MACE, but no such difference in all-cause mortality, myocardial infarction or heart failure was observed. Appropriate supplementation of vitamin D in selected populations might be cardioprotective in nature and warrants extensive trials.