The effects of vitamin D supplementation on proatherogenic inflammatory markers and carotid intima media thickness in subjects with metabolic syndrome: a randomized double-blind placebo-controlled clinical trial

Purpose Metabolic syndrome may predispose to cardiovascular diseases. Since, in recent studies, vitamin D is advocated for cardioprotective roles, this study was designed to investigate the effects of vitamin D supplementation on proatherogenic inflammatory markers and common carotid intima media thickness in subjects with metabolic syndrome. Methods This randomized double blind clinical trial was conducted in Tabriz, Iran. Eligible subjects ( n = 80) with metabolic syndrome were recruited thorough advertisement and randomized to receive either vitamin D (50,000 IU/week) or matching placebo for 16 weeks. Interlukin-6, high sensitivity C-reactive protein, vascular cell adhesion molecule-1, E-selectin, and common carotid intima media thickness were measured at the beginning and end of the study. The study was registered at http://www.irct.ir (code: IRCT201409033140N14). Results Sixteen weeks supplementation with vitamin D increased median of serum 25-hydroxy vitamin D [25(OH)D] and mean calcium levels ( p