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

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.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).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.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.