Effect of Vitamin D supplementation on blood pressure in hypertensive individuals with hypovitaminosis D: a systematic review and meta-analysis

Abstract

In the present study, we aimed to conduct a literature review and meta-analysis to assess the effect of Vitamin D supplementation on SBP and DBP levels in individuals with hypertension and hypovitaminosis D. PubMed, Scopus, Web of Science, and SciELO were systematically searched for relevant publications until January 2023. The review has been registered at PROSPERO (CRD42023400035). To compare the effects of vitamin D with placebo, the mean differences with 95% confidence intervals (95% CIs) were pooled based on the random-effects model. Subgroup analyses were performed to identify the source of heterogeneity, and assessment of study quality was conducted using the GRADE approach. Publication bias was evaluated using funnel plots and Egger's tests. In total, 14 randomized controlled trials (RCTs) were included in this systematic review, and 11 trials were selected for meta-analysis. The data showed that Vitamin D significantly decreased SBP levels; however, it did not affect DBP levels. In subgroup analysis, Vitamin D supplementation significantly decreased in SBP in studies involving individuals over 60 years of age, with a dose greater than 400 000 IU, duration greater than 8 weeks, frequency of weekly supplementation in studies conducted in Asia. In addition, subgroup analysis revealed a significant reduction in DBP in the weekly frequency subgroups and in the studies carried out in Asia. This meta-analysis indicated that Vitamin D significantly reduced the SBP in individuals with hypertension and hypovitaminosis D. Further, well designed trials are necessary to validate these results.