The effect of supplementary calcium on blood pressure in healthy adult women aged 18-30 years in Tehran, Iran

INTRODUCTION: Cardiovascular disease is the major cause of mortality in developed countries and has an increasing trend in developing countries. There are some evidences that calcium supplementation may decrease blood pressure and consequently cardiovascular disease, but they are not conclusive and there is no agreement in this respect. The aim of the present study was to assess the effect of supplementary calcium on systolic and diastolic blood pressure in healthy adult women aged 18–30 years. MATERIALS AND METHODS: Seventy-five normotensive volunteers were randomly divided into two groups, the treatment group received 1000 mg/day calcium (four doses of 625 mg calcium carbonate) for 1 month and the control group received placebo (dextrose). Systolic and diastolic blood pressure was determined before and after intervention in supine position after 10 min of rest. RESULTS: The mean daily calcium intake from food was 773.9 mg in treatment and 721 mg in control group (no significant difference) but in both the groups dietary calcium intake was less than the recommended dietary allowance: After calcium supplementation, the mean change of systolic blood pressure was not significant in the two groups, but diastolic blood pressure reduced in treatment group and increased in control group (−4.9 vs 2.6 mmHg) (P < 0.05). CONCLUSIONS: These results suggest that, calcium supplementation does not have any effect on systolic blood pressure of our volunteers but can decrease diastolic blood pressure significantly and therefore it seems that calcium supplementation may be useful for people with increased diastolic blood pressure, especially for those who receive less calcium than recommended dietary allowance.