Vitamin D yields blood pressure-lowering benefit

Supplementation with vitamin D appears to have a favourable effect on blood pressure levels, as shown in a study.

For the study, researchers conducted a systematic review and umbrella meta-analysis of meta-analyses of clinical trials in which the impact of vitamin D on blood pressure was evaluated. Multiple online databases were searched for relevant literature.

Random effects analysis was used to pool the overall effect size based on the standardized mean differences (SMDs) and weighted mean differences (WMDs) separately. Meanwhile, the Measurement Tool for Assessing Multiple Systematic Reviews 2 questionnaire was used to assess the quality of included meta-analyses.

A total of 21 meta-analyses met the eligibility criteria and were included in the umbrella review. Pooled data showed that vitamin D supplementation led to a significant reduction in systolic blood pressure based on analysis of WMD effect sizes (–0.69 mm Hg, 95 percent confidence interval [CI], –1.35 to –0.04; p<0.038; I²=46.7 percent; p=0.021). However, supplementation had no considerable impact based on analysis of SMD effect sizes (–0.05 mm Hg, 95 percent CI, –0.24 to 0.14; p=0.615).

For diastolic blood pressure, vitamin D supplementation conferred a beneficial effect based on analysis of WMD effect sizes (–0.66 mm Hg, 95 percent CI, –1.05 to –0.27; p<0.001; I²=56.4 percent; p=0.004) but not that of SMD effect sizes (–0.04 mm Hg, 95 percent CI, –0.13 to 0.04; p=0.328; I²=53.4 percent; p=0.057).

The findings suggest that vitamin D could be considered an efficient adjuvant for improving blood pressure, the researchers said.