IRCT201703129014N151 IRCT 2017-03-12 Vice-chancellor for Research the Technology, Hamadan University of Medical Sciences Effect of vitamin D supplementation versus placebo on hypertension in patients with vitamin D deficiency Effect of vitamin D supplementation versus placebo on hypertension in patients with vitamin D deficiency: a double blind randomized clinical trial 2017-04-04 anticipated 208 Complete https://irct.ir/trial/9589 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: Randomization: The patients will be randomly assigned to intervention and control groups using block randomization. Blinding: Patients will be unaware of the type of intervention. The physician who will examine the patients will not be aware of the intervention. The analyzer will be unaware of the type of interventions. Therefore, the trial will be run as double blind. 2 Vitamin D deficiency. Intervention 1: Intervention group: Routine anti-hypertensive drugs plus gelatin tablet vitamin D (Calciferol) based on Vitamin D serum level (50,000 U once a week oral in subjects with Vitamin D serum level less than 20 ngr/mL and 1000 U in subjects with serum level between 20 to 30 ngr/mL) for 2 months. Intervention 2: Control group: Routine anti-hypertensive drugs plus gelatin tablet placebo once a week for 2 months.