This systematic review and meta-analysis examines the effect of six supplements – vitamin C, vitamin D, vitamin E, calcium, magnesium and potassium – on blood pressure in a general, normotensive (non-hypertensive) population.
The analysis is based on 87 randomized, controlled trials with a total of 12,526 participants. The results show that
– Magnesium and potassium reduced systolic blood pressure (SBP) by an average of 2.79 mmHg and 2.10 mmHg.
– Calcium and magnesium lowered diastolic blood pressure (DBP) by 1.63 mmHg and 1.56 mmHg.
– Vitamin E lowered systolic blood pressure by 1.76 mmHgwhile vitamin C and D showed no significant effects.
The studies suggest that magnesium is the most promising dietary supplement for natural blood pressure regulation. Although the observed effects appear comparatively small, a reduction in systolic blood pressure of 2 mmHg can significantly reduce the risk of cardiovascular disease.
Conclusion: Magnesium, potassium and calcium have the greatest potential to support healthy blood pressure. Future studies should investigate optimal dosages and long-term effects.
Background:
Hypertension (high blood pressure) is one of the most important preventable risk factors for cardiovascular disease and premature mortality worldwide. Studies have shown that even within a “normal” blood pressure range (above 110-115/70-75 mmHg), the risk of cardiovascular disease increases. While drugs exist to lower blood pressure, natural alternatives such as dietary supplements are gaining interest. This meta-analysis examines the effectiveness of six dietary supplements – vitamins C, D, E, calcium, magnesium and potassium – in lowering blood pressure in normotensive adults.
Methodology:
- Study design: Systematic review and meta-analysis of 87 randomized controlled trials (RCTs).
- Participants: 12,526 adults without diagnosed hypertension.
- Interventions: Supplementation with vitamin C, D, E, calcium, magnesium or potassium compared to placebo.
- Endpoints: Changes in systolic (SBP) and diastolic (DBP) blood pressure.
Results:
1. Positive effects on systolic blood pressure (SBP):
- Magnesium: -2.79 mmHg (p < 0.05)
- Potassium: -2.10 mmHg (p < 0.05)
- Calcium: -1.37 mmHg (p < 0.05)
- Vitamin E: -1.76 mmHg (p < 0.05)
- Vitamin C and D showed no significant reduction.
2. Positive effects on diastolic blood pressure (DBP):
- Calcium: -1.63 mmHg (p < 0.05)
- Magnesium: -1.56 mmHg (p < 0.05)
- Potassium showed a reduction of -1.28 mmHgbut did not reach statistical significance.
3. No significant effects for vitamin C and D:
- Vitamin C: -1.45 mmHg (SBP), -0.47 mmHg (DBP)
- Vitamin D: -0.19 mmHg (SBP), +0.11 mmHg (DBP)
Discussion:
The results indicate that magnesium and potassium are the most promising supplements for lowering blood pressure. These two minerals play a crucial role in vascular relaxation and the regulation of fluid balance. Magnesium in particular showed a clinically relevant reduction in both systolic and diastolic blood pressure.
Calcium also led to a significant reduction in blood pressure, possibly through its role in vascular tension and sodium excretion. Vitamin E showed a slight but significant reduction in SBP, which could be attributed to its antioxidant properties.
Vitamin C and D had no measurable effects on blood pressure, confirming existing evidence that their antihypertensive effects may be more indirect via other health benefits.
Clinical relevance:
Even small reductions in blood pressure of 2 mmHg can reduce the risk of strokes by 10% and heart disease by 7%. A change in diet or targeted supplementation could be a preventive measure, especially for people with slightly elevated blood pressure who do not require medical treatment.
Limitations:
- The studies had different dosages and application periods, which makes comparability difficult.
- The long-term effects and optimal dosages have not yet been sufficiently researched.
- The analysis focuses on normotensive people, so that no statement can be made about the effectiveness in hypertensive patients.
Conclusion:
This meta-analysis shows that in particular magnesium, potassium and calcium can be effective natural ways of lowering blood pressure. The results emphasize the need for further research on optimal dosage and long-term effects. The integration of these nutrients into a healthy diet could be an important strategy for the prevention of cardiovascular disease.