From the Guidelines
Vitamin C and magnesium should not be relied upon as primary preventive measures for atrial fibrillation, and their use should be approached with caution due to limited evidence and potential side effects. The most recent and highest quality studies do not provide strong evidence for the use of vitamin C and magnesium in preventing atrial fibrillation 1, 2. For magnesium, some studies suggest that maintaining normal levels may help reduce AF risk, but routine supplementation is not recommended unless you have a documented deficiency. If supplementing, typical magnesium doses range from 200-400mg daily, with magnesium glycinate or citrate being better tolerated forms. For vitamin C, while some research indicates it may help reduce post-surgical AF risk through its antioxidant properties, evidence for general AF prevention is weak. Typical vitamin C supplementation ranges from 500-1000mg daily.
The most effective AF prevention strategies remain controlling traditional risk factors like hypertension, maintaining a healthy weight, limiting alcohol, treating sleep apnea, and taking prescribed medications, as recommended by guidelines such as those from the European Heart Journal 3 and the American College of Cardiology Foundation 4. Always consult with your healthcare provider before starting supplements, as they may interact with medications and excessive doses can cause side effects like diarrhea with magnesium or kidney stones with high-dose vitamin C. The quality of evidence underlying guidelines for AF management is a concern, and a holistic approach to AF management is needed, incorporating stroke prevention, addressing symptoms, and risk factor management 5, 6.
From the Research
Vitamin C and Magnesium for Atrial Fibrillation Prophylaxis
- The use of vitamin C for preventing atrial fibrillation in high-risk patients has been studied, with results indicating that it may prevent post-operative atrial fibrillation in some countries outside of the USA, and may also shorten the duration of hospital stay and ICU stay of cardiac surgery patients 7.
- However, the evidence for magnesium prophylaxis of new-onset atrial fibrillation is limited, with a systematic review and meta-analysis finding that administration of magnesium did not significantly reduce the incidence of new-onset atrial fibrillation compared to placebo 8.
- Other studies have investigated the use of anti-arrhythmic drugs, investigational agents, and innovative approaches for atrial fibrillation therapy, including the introduction of agents with selective affinity to ion channels specifically involved in atrial repolarization 9.
- Additionally, some studies have suggested that omega-3 fatty acids may have anti-arrhythmic effects, although the evidence is not yet robust enough to transform current clinical practice 10.
- The use of antithrombotic and anticoagulant therapy for atrial fibrillation is also important, with oral anticoagulation being recommended for most patients unless contraindicated 11.
- Overall, while there is some evidence to support the use of vitamin C and magnesium for atrial fibrillation prophylaxis, further research is needed to determine the optimal dosage protocol and to identify the patient groups that benefit the most 7, 8.