Magnesium Supplementation and Coronary Calcium Scores
Based on current evidence, magnesium supplementation has not been consistently shown to reduce coronary calcium scores, with contradictory findings from clinical studies. 1
Evidence on Magnesium and Vascular Calcification
In animal models and in vitro studies, magnesium has demonstrated protective effects against phosphate-induced vascular calcification by delaying the extracellular formation of hydroxyapatite 1
Clinical studies examining magnesium supplementation's effect on coronary artery calcification have shown contradictory results:
The Framingham Heart Study demonstrated an inverse association between self-reported magnesium intake and coronary artery calcification in community-dwelling participants free of cardiovascular disease 2
Similarly, the Genetics of Atherosclerotic Disease study found that serum magnesium levels were independently associated with lower coronary artery calcification, with subjects in the highest quartile of serum magnesium having 42% lower odds of coronary calcium scores >0 3
However, a cross-sectional study from the ELSA-Brasil cohort found no significant association between magnesium intake and coronary artery calcification after adjustments for diet, lifestyle, and clinical characteristics 4
Magnesium and Cardiovascular Health
Magnesium plays important roles in glucose metabolism, vascular tone, and inflammation, making it a potential dietary factor in cardiovascular disease prevention 4, 5
Hypomagnesemia is common in hospitalized patients, especially in the elderly with coronary artery disease and/or chronic heart failure 5
Magnesium supplementation has been shown to:
- Improve myocardial metabolism
- Inhibit calcium accumulation and myocardial cell death
- Improve vascular tone, peripheral vascular resistance, and cardiac output
- Reduce cardiac arrhythmias
- Improve lipid metabolism
- Reduce vulnerability to oxygen-derived free radicals
- Improve human endothelial function
- Inhibit platelet function 5
The American Heart Association recognizes magnesium's benefit in treating torsades de pointes and ventricular arrhythmias, and notes that in heart failure patients, hypomagnesemia is associated with more frequent ventricular arrhythmias 6
Clinical Implications and Recommendations
Despite theoretical benefits, routine administration of magnesium to patients with myocardial infarction has no significant clinical mortality benefit 1
The ISIS-4 trial, which enrolled 58,000 patients, showed a trend toward increased mortality rates when magnesium was given in-hospital for primary prophylaxis to patients within the first 4 hours of known or suspected acute myocardial infarction 1
For patients with chronic kidney disease, a large pragmatic cluster-randomized clinical trial (Dial-Mag Canada) is currently evaluating the effects of different concentrations of magnesium in dialysate on >25,000 hemodialysis patients, with estimated completion in 2028 1
Gastrointestinal adverse effects are a limitation of oral magnesium supplementation and may reduce adherence 1
There is a modest relationship between dietary magnesium intake and reduced risk of coronary heart disease in male subjects, but no noted decrease in women 7
Conclusion
While some observational studies suggest an inverse relationship between magnesium levels and coronary calcium scores, interventional studies have produced mixed results. Current evidence does not consistently support magnesium supplementation as an effective strategy to reduce coronary calcium scores. More definitive clinical trials are needed before specific recommendations can be made for using magnesium supplementation to target coronary calcification.