The effect of vitamin D3 on blood pressure in people with vitamin D deficiency A system review and meta-analysis

Objective: To evaluate the effect of vitamin D-3 on blood pressure in people with vitamin D deficiency. Methods: Randomized controlled trials (RCTs) were electronically searched databases including CNKI, VIP, WanFang Data, the Cochrane Library, PubMed, and EMbase which were about oral vitamin D-3 among people with vitamin D deficiency from inception to December 2017. Two reviewers independently screened literature according to the inclusion and extracted data; meta-analysis was performed using RevMan5.3. Results: A total of 17 RCTs with 22 arms involving 1687 participants were included. The results of meta-analysis showed that, there were no significant differences between the vitamin D deficiency group and the control group on the level of change in systolic pressure (Delta SBP) [weighted mean difference (WMD)=-1.94, 95% confidence interval (CI) (-3.93,0.04) P=.06] and on the level of change in diastolic pressure (Delta DBP) [WMD=-0.50, 95% CI (-1.17, 0.17) P=.14]. The results of subgroups showed that, there were statistically significant differences in the age of >50 years subgroup on Delta SBP [WMD=-2.32, 95% CI (-4.39, -0.25) P=.03]; there were statistically significant differences in the hypertension subgroup on Delta SBP [WMD=-6.58, 95% CI (-8.72, -4.44) P<.00001]; there were statistically significant differences in the hypertension subgroup on Delta DBP [WMD=-3.07, 95% CI (-4.66, -1.48) P=.0002]; there were statistically significant differences in the body mass index (BMI) >30 subgroup on Delta SBP [WMD=-3.51, 95% CI (-5.96, -1.07) P=.005]. Conclusion: Oral vitamin D-3 has no significant effect on blood pressure in people with vitamin D deficiency. It reduces systolic blood pressure in people with vitamin D deficiency that was older than 50 years old or obese. It reduces systolic blood pressure and diastolic pressure in people with both vitamin D deficiency and hypertension.