Vitamin D, K, and Magnesium Interactions with Clopidogrel

Key Distinction: Vitamin K vs. Vitamin K Antagonists

• Vitamin K supplementation itself does not interact with clopidogrel's antiplatelet mechanism, according to the American Heart Association guidelines 1
• Vitamin K antagonists (warfarin) combined with clopidogrel create a 3.5-4 fold increased bleeding risk compared to aspirin alone, as reported by the American College of Cardiology 2

Magnesium Considerations

• No direct pharmacokinetic or pharmacodynamic interactions between magnesium supplements and clopidogrel have been documented in major guidelines from the American Heart Association 3
• Magnesium supplementation can be safely continued in patients taking clopidogrel without dose adjustment, as stated by the American College of Cardiology 3

Practical Management Algorithm

• Vitamin K supplements can be used safely in patients on clopidogrel, but should not be confused with vitamin K antagonist medications (warfarin), according to the American Stroke Association 5
• If a patient is on warfarin + clopidogrel, vitamin K supplementation should be avoided as it will antagonize warfarin's anticoagulant effect, as reported by the American College of Cardiology and the American Stroke Association 2, 5