Triple-blind randomized clinical trial were performed on 98 hypertensive women of postmenopausal ages in 2019. They were randomly divided into a control group of 50 members and a treatment group of 48 members. Randomization was based on block randomization method with block size=2 and ratio 2:2 for drug and placebo. To achieve triple blinding, patients were divided into "A" and "B" groups(by the mentioned randomization method). "A" was assigned to treatment and "B" to placebo but this assignment was not revealed to the patients, trial conductors and result assessors till the end of data analysis.
Oral calcium-D supplements were given to the treatment group in the form of tablets named Vana Flex® from Vana Darou Gostar Co. (VDG Co.). Each tablet contained 500 milligrams of calcium carbonate and 200 international units (IU) of vitamin D3(cholecalciferol). The placebo pills for the control group were chose in a way that looked similar to the calcium-D tablets in shape and color. The placebo tablets we used in this trial were made up of magnesium stearate 0.2 %, starch 10%, avicel 30%, and lactose 60%. The calcium-D and placebo tablets were both packed identically in order to assure blindness and the patients were told to take one tablet per day. The treatment and placebo group started drugs beside their previous hypertension medications.
24-hour Ambulatory blood pressure monitoring (ABPM) was done primarily for all of the participants to record the initial blood pressure of patients and after completion of study period
