The effect of vitamin D supplementation on flow-mediated dilatation, oxidized LDL and intracellular adhesion molecule 1 on type 2 diabetic patients with hypertension: A randomized, placebo-controlled, double-blind trial.

AIMS:Current study aimed to evaluate the effect of vitamin D supplementation on flow-mediated dilatation (FMD), oxidized LDL (oxLDL) and intracellular adhesion molecule 1 (ICAM1) in type 2 diabetic patients with hypertension. METHODS:In a double-blinded, placebo-controlled trial, 44 patients were randomly divided into vitamin D group (2000 IU/d, n = 23) and placebo group (control, n = 21) for 12 weeks. Vascular function with FMD, Serum 25-OH vitamin D, oxLDL and ICAM1 were assessed at the baseline and after the intervention. This clinical trial was registered at Iranian Registry of Clinical Trials (IRCT20191223045861N1). RESULTS:In intervention group serum level of vitamin D increased from 32.42 ± 10.56 to 40.45 ± 12.94 (p < 0.001). In the vitamin D group, oxLDL and ICAM1 significantly decreased and FMD increased significantly in both groups (p < 0.001). The level of oxLDL (p = 0.017) and ICAM1 (p < 0.001) were significantly lower in the vitamin D group than the placebo group and FMD (p < 0.001) was significantly higher in the vitamin D group. CONCLUSIONS:Vitamin D supplementation of 2000 IU/d for 12 weeks can improve endothelial function and decrease ICAM1 and oxLDL in type 2 diabetic patients with hypertension.