Evidence from the studies included in this systematic review did not demonstrate that vitamin D supplementation in adults , results in an improvement in circulating inflammatory and endothelial function biomarkers/parameters .
This systematic review does not therefore support the use of vitamin D supplementation as a therapeutic or preventative measure for CVD in this respect
This systematic review aims to evaluate r and omised controlled trials ( RCTs ) investigating the effect of vitamin D supplementation on  endothelial function and inflammation in adults .
Randomized controlled trial of vitamin D supplement on endothelial function in patients with type 2 diabetes.
BACKGROUND Suboptimal vitamin D status is associated with endothelial dysfunction and an increased risk of cardiovascular diseases but it is unclear whether vitamin D supplementation is beneficial . The aim was to investigate the effect of vitamin D supplementation on endothelial function in patients with type 2 diabetes mellitus ( DM ) . METHODS In a double-blind , placebo-controlled trial , we r and omized 100 type 2 DM patients to vitamin D supplement  ( 5000 IU/day , n = 50 ) or placebo ( controls , n = 50 ) for 12 weeks . Assessment of vascular function with brachial artery flow-mediated dilatation ( FMD ) , circulating levels of endothelial progenitor cells ( EPCs ) and brachial-ankle pulse wave velocity , and metabolic parameter , high-sensitivity C-reactive protein ( hsCRP ) and oxidative stress markers were performed before and after the supplementation . RESULTS After 12 weeks , vitamin D treated patients had significant increases in serum 25-hydroxyvitamin D [ 25(OH)D ] concentration ( treatment effect 34.7 ng/mL , 95 % CI 26.4 - 42.9 , P < 0.001 ) and serum ionized calcium ( treatment effect 0.037 mmol/L , 95 % CI 0.007 - 0.067 , P = 0.018 ) ; decreased serum parathyroid hormone concentration ( treatment effect -0.55 pmol/L , 95 % CI -1.08 to -0.02 , P = 0.042 ) compared to patients who received placebo . Nevertheless , vitamin D supplementation did not improve vascular function as determined by FMD , circulating EPC count or baPWV ( all P > 0.05 ) . Furthermore , hsCRP , oxidative stress markers , low- and high-density lipoprotein and glycated hemoglobin were also similar between two groups ( all P > 0.05 ) . CONCLUSION In patients with type 2 DM , 12 weeks oral supplementation of vitamin D did not significantly affect vascular function or serum biomarkers of inflammation and oxidative stress . CLINICAL TRIAL NUMBER HKCTR-867 , www.hk clinical trials.com
Evidence from the studies included in this systematic review did not demonstrate that vitamin D supplementation in adults , results in an improvement in circulating inflammatory and endothelial function biomarkers/parameters .
This systematic review does not therefore support the use of vitamin D supplementation as a therapeutic or preventative measure for CVD in this respect
This systematic review aims to evaluate r and omised controlled trials ( RCTs ) investigating the effect of vitamin D supplementation on  endothelial function and inflammation in adults .