Vitamin D Versus Placebo in Improvement of Endothelial Dysfunction: A Meta‐Analysis of Randomized Clinical Trials

Abstract

SUMMARYAims: The possible effect of vitamin D administration in humans on endothelial dysfunction (ED) still remains undetermined. The current meta-analysis was performed to evaluate if vitamin D could improve ED. Methods: Randomized, double-blind, and placebo-controlled clinical trials were identified by systematic search of the PubMed, the Cochrane Library, the Web of Science and the Scopus data bases, as well as different reviews and clinical trials articles. A random effects model was used to calculate the pooled overall effect on flow-mediated dilation (FMD) linked to the vitamin D administration. Meta-regression and subgroup analyses were performed to evaluate the impact of study characteristics on the effect of vitamin D administration on FMD. Results: A total of eight studies with nine relevant study arms were identified. The obtained results of pooled analysis showed that vitamin D administration did not improve FMD (eight studies, 529 subjects; weighted mean difference (WMD): 0.96%, 95% CI: À1.24% to 2.06%; P = 0.09). This was probably due to significant heterogeneity in between included trials (I 2 = 84%, P < 0.00001). On the other hand, subgroup analysis demonstrated that vitamin D improved FMD in trials that lasted <16 weeks; if systolic blood pressure (SBP) was higher than 140 mmHg and in trials where diastolic blood pressure (DBP) was <80 mmHg. Conclusion: Although the current evidence clearly demonstrates that in certain conditions vitamin D can improve ED, a larger number of clinical trials are needed to confirm this assumption to confirm or reject the final statement on this topic.

Vitamin D Attenuates Endothelial Dysfunction in Uremic Rats and Maintains Human Endothelial Stability

“…In line with our results, Wu‐Wong et al have reported that paricalcitol can improve endothelial‐dependent relaxation in uremic rats independent from effects on PTH serum concentration 16, 17. Recently, randomized clinical trials conducted in patients with CKD also demonstrated that treatment with active vitamin D leads to significantly favorable changes in endothelial function 18, 19, 33, 34, 35…”

Vitamin D and progression of carotid intima‐media thickness in HIV‐positive Canadians

“…Vitamin D 3 supplementation reduces all-cause mortality in elderly people [3], but a causal benefit for CVD-specific mortality has not been established. Results from studies examining CVD effects of vitamin D supplementation have been inconsistent [4][5][6][7][8][9][10][11][12][13].…”

Anti-cancer agents and endothelium

“…It hampers ROS formation in cardiomyocytes, but its effect on endothelium needs further evaluation [92]. Some studies indicated a beneficial effect of vitamin D supplementation on endothelium by an increase in FMD of the brachial artery [93]. Vitamin D may be particularly useful in an oncological setting due to its demonstrated in vivo and in vitro antiangiogenic properties [94].…”

“…Vitamin D may be particularly useful in an oncological setting due to its demonstrated in vivo and in vitro antiangiogenic properties [94]. According to meta-analysis [93] vitamin D supplementation significantly decreases mortality due to cancer and CV events. The effect of vitamin D on endothelium still needs further evaluation, especially to establish a proper supplemented dosage.…”