This is a double blinded, placebo controlled trial. Patients who meet the inclusion criteria will be randomized to placebo or 25(OH)D3, 4,000 IU/d orally for 16 weeks. Enrolled patients will be tested for 24h-blood pressure, brachial arterial blood flow, vascular inflammatory markers and macrophage inflammatory response to modified-lipoproteins at baseline, middle and at the end of the study.