Acute effects of calcium supplements on blood pressure: randomised, crossover trial in postmenopausal women.
Study Goal
The researchers aimed to investigate the acute effects of calcium supplements on blood pressure in postmenopausal women and confirm previous findings that calcium attenuates the post-breakfast reduction in systolic blood pressure.
Results Summary
The study found that calcium supplementation led to smaller reductions in systolic blood pressure compared to placebo (by 6-9 mmHg at 4-6 hours post-dose), while diastolic blood pressure changes were similar between groups. Ionized and total calcium concentrations increased significantly after calcium intake.
Population
40 healthy postmenopausal women (mean age 71 years, BMI 27.2 kg/m²).
Effective Dosage
Not specified in the abstract.
Duration
Acute effects measured over 6 hours post-dose.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
calcium supplements | increase | cardiovascular risk | - | - | appear to increase | #1 |
calcium supplements | increase | ionised calcium concentrations | 40 healthy postmenopausal women | - | increased | #2 |
calcium supplements | increase | total calcium concentrations | 40 healthy postmenopausal women | - | increased | #3 |
calcium supplements | decrease | systolic blood pressure | 40 healthy postmenopausal women | - | decreased | #4 |
calcium supplements | decrease | systolic blood pressure | 40 healthy postmenopausal women | 6 mmHg at 4 h | reduction was smaller | #5 |
calcium supplements | decrease | systolic blood pressure | 40 healthy postmenopausal women | 9 mmHg at 6 h | reduction was smaller | #6 |
calcium supplements | no change | diastolic blood pressure | 40 healthy postmenopausal women | - | reduction was similar | #7 |
calcium supplements | decrease | post-breakfast reduction in systolic blood pressure | postmenopausal women | around 6-9 mmHg | attenuates | #8 |
UNLABELLED: Calcium supplements appear to increase cardiovascular risk, but the mechanism is unknown. We investigated the acute effects of calcium supplements on blood pressure in postmenopausal women. The reduction in systolic blood pressure was smaller after calcium compared with the placebo in the hours following dosing. INTRODUCTION: Calcium supplements appear to be associated with increased cardiovascular risk; however, the mechanism of this is uncertain. We previously reported that blood pressure declined over a day in older women, and that this reduction was smaller following a calcium supplement. To confirm this finding, we investigated the acute effects of calcium supplements on blood pressure. METHODS: This was a randomised controlled crossover trial in 40 healthy postmenopausal women (mean age 71 years and BMI 27.2 kg/m RESULTS: Ionised and total calcium concentrations increased after calcium (p < 0.0001 versus placebo). Systolic blood pressure decreased after both calcium and placebo, but significantly less so after calcium (p = 0.02). The reduction in systolic blood pressure from baseline was smaller after calcium compared with placebo by 6 mmHg at 4 h (p = 0.036) and by 9 mmHg at 6 h (p = 0.002). The reduction in diastolic blood pressure was similar after calcium and placebo. CONCLUSIONS: These findings are consistent with those of our previous trial and indicate that the use of calcium supplements in postmenopausal women attenuates the post-breakfast reduction in systolic blood pressure by around 6-9 mmHg. Whether these changes in blood pressure influence cardiovascular risk requires further study.