The impact of vitamin D supplement intake on vascular endothelial function; a systematic review and meta-analysis of randomized controlled trials

Abstract

Aim: to systematically review and conduct a meta-analysis of randomized controlled trials investigating the impact of vitamin D supplementation on endothelial function. Method: We searched PubMed-Medline, SCOPUS, Web of Science and Google Scholar (until June 2016) to detect prospective studies evaluating the impact of vitamin D supplementation on endothelial function indexes. We used random effects models (using DerSimonian-Laird method) and generic inverse variance methods to synthesize quantitative data. We used the leave-one-out method for sensitivity analysis. To quantitatively assess the heterogeneity we used the I2 index. Systematic review registration: CRD42016039329. Results: From a total of 213 entries identified, 12 studies were appropriate for inclusion into the final analysis. The meta-analysis indicated a significant enhancement in flow-mediated dilation (FMD) following D supplementation (vitamin D intervention group versus control group 1.27 %, (95% CI 0.20 to 2.34, N = 11 arms, heterogeneity p = 0.054; I2 51.2 %). These findings were robust in sensitivity analyses. Conclusions: This meta-analysis suggested that vitamin D supplementation may improve endothelial function. Randomized control trials with a longer-term follow-up are warranted to clarify the existing controversies and shed light on the potential underlying mechanisms.

Effect of Vitamin D Supplementation on Markers of Vascular Function: A Systematic Review and Individual Participant Meta‐Analysis

“…Our results are consistent with our previous work that failed to find a beneficial effect of vitamin D therapy on BP and are also in accord with 2 recent, smaller meta‐analyses examining arterial stiffness and endothelial function . One further recent meta‐analysis, examining only FMD, showed a slightly greater benefit (treatment effect of vitamin D was 1.27% for FMD), perhaps attributable to differences in both study selection and the data used; our analysis had the benefit of access to IPD, which allowed us to verify the accuracy of published data and data used in previous meta‐analyses. The results are also consistent with recent data suggesting no effect of vitamin D supplementation on plasma N‐terminal pro‐B‐type natriuretic peptide levels or echocardiographic indices in older people after 12 months of therapy …”

Arterial Stiffness in the Heart Disease of CKD

“…The effect of vitamin D analog supplementation on vascular function has been evaluated in three meta-analyses that also included a minority of patients with CKD. [96][97][98] In two meta-analyses, vitamin D analog supplementation was associated with improved endothelial function. 97,98 In the third meta-analysis, 96 paricalcitol, but not vitamin D 2 or vitamin D 3 , improved endothelial function.…”

“…[96][97][98] In two meta-analyses, vitamin D analog supplementation was associated with improved endothelial function. 97,98 In the third meta-analysis, 96 paricalcitol, but not vitamin D 2 or vitamin D 3 , improved endothelial function. However, a high vitamin D level carries the risk of aggravating hyperphosphatemia, which could again be detrimental to endothelial function.…”

Impact of vitamin D supplementation on C-reactive protein; a systematic review and meta-analysis of randomized controlled trials

“…Studies suggest vitamin D suppelemnation may reduce circulating CRP levels and some other plasma inflammatory cytokines. However, inconsistent results are reported across completed randomized trials [5][6][7]. Cytokines such as interleukin 6 (IL-6), interleukin 10 (IL-10) and tumor necrosis factor-alpha (TNF-alpha) mediate the inflammatory response in human tehrfore they can serve as potential biomarkers of chronic inflammatory diseases [8][9][10].…”