From the Guidelines
Magnesium supplementation may modestly lower blood pressure, although its effectiveness is not as strong as potassium-rich foods, and it cannot be recommended for general cardiovascular disease prevention. When considering magnesium supplementation for blood pressure management, it is essential to weigh the potential benefits against the current evidence. According to a comprehensive review published in Circulation in 2016 1, short-term trials have shown that calcium and magnesium supplements can modestly lower blood pressure, but there is substantial heterogeneity among studies. Key points to consider include:
- The evidence for magnesium supplementation is not as strong as for potassium-rich foods, which have been consistently shown to lower blood pressure and reduce the risk of cardiovascular disease 1.
- Magnesium supplements may be beneficial for individuals with magnesium deficiency or hypertension, but their effectiveness for general cardiovascular disease prevention is unclear 1.
- Typical supplementation ranges from 300-500 mg of elemental magnesium daily, with common forms including magnesium citrate, glycinate, or oxide.
- Magnesium works by relaxing blood vessels, acting as a natural calcium channel blocker, and helping regulate sodium and potassium balance—all factors that influence blood pressure.
- It's generally well-tolerated, though higher doses may cause digestive issues like diarrhea.
- Before starting magnesium supplements, it is crucial to consult with a healthcare provider, especially if you have kidney disease or take medications that might interact with magnesium. Overall, while magnesium supplementation may have some benefits for blood pressure management, it should be considered as part of a comprehensive approach that includes a healthy diet, regular exercise, and prescribed medications, under the guidance of a healthcare provider.
From the Research
Magnesium Supplementation and Blood Pressure
- Magnesium intake of 500 mg/d to 1000 mg/d may reduce blood pressure (BP) as much as 5.6/2.8 mm Hg 2
- The combination of increased intake of magnesium and potassium coupled with reduced sodium intake is more effective in reducing BP than single mineral intake and is often as effective as one antihypertensive drug in treating hypertension 2
- Magnesium supplementation above 15 mmol per day are required to normalize high blood pressure in unmedicated hypertensive patients while 15 mmol per day will lower high blood pressure in patients treated with anti-hypertensive medications 3
Effects of Magnesium Supplementation on Blood Pressure
- A meta-analysis of 7 studies involving 135 hypertensive subjects on anti-hypertensive medication demonstrated a mean change of -18.7 mmHg in systolic blood pressure and -10.9 mmHg in diastolic blood pressure with oral magnesium supplementation 4
- Another meta-analysis of 34 trials involving 2028 participants found that magnesium supplementation at a median dose of 368 mg/d for a median duration of 3 months significantly reduced systolic BP by 2.00 mm Hg and diastolic BP by 1.78 mm Hg 5
- Magnesium supplementation has been shown to have blood pressure-lowering effects, and emerging data reveal potential mechanisms by which magnesium may influence blood pressure, including effects on total peripheral resistance and cardiac output 6
Mechanisms of Magnesium's Effect on Blood Pressure
- Magnesium status has a direct effect upon the relaxation capability of vascular smooth muscle cells and the regulation of the cellular placement of other cations important to blood pressure 3
- Magnesium deficiency alters calcium metabolism, creating high intracellular calcium and low serum calcium states, which can lead to hypertension 3
- Magnesium supplementation can increase the effectiveness of all antihypertensive drug classes and may improve insulin sensitivity, hyperglycemia, diabetes mellitus, left ventricular hypertrophy, and dyslipidemia 2