High-Dose Vitamin K May Help Reverse Warfarin-Induced Arterial Calcification

Educational only — not medical advice.

Matrix Gla-protein (MGP) is one of the body’s strongest natural inhibitors of arterial calcification. For MGP to function properly, it must be activated by vitamin K . The anticoagulant drug warfarin interferes with vitamin K metabolism, which in turn inhibits MGP and may promote calcification of the arteries.

A landmark animal study published in Blood (1 April 2007; 109(7):2823-2831) explored this relationship using a rat model:

Study Design

  • Arterial calcification was induced in rats by administering warfarin for six weeks.

  • The rats were then divided into four groups for an additional six weeks:

    1. Continued warfarin

    2. Low-dose vitamin K (5 mcg/g food)

    3. High-dose vitamin K1 (100 mcg/g food)

    4. High-dose vitamin K2 (100 mcg/g food)

Key Findings

  • Calcification continued to progress in rats receiving warfarin or low-dose vitamin K.

  • High-dose vitamin K1 or K2 reduced arterial calcification by up to 50%.

  • High-dose vitamin K improved arterial elasticity, making the vessels more supple.

  • Areas of calcification contained locally depleted vitamin K, suggesting a tissue-specific deficiency.

Takeaway

The study demonstrates that, at least in animals, high-dose vitamin K can partially reverse warfarin-induced arterial calcification and may restore some arterial flexibility. While animal data cannot be applied directly to humans, it offers an important mechanistic insight: vitamin K plays a critical role in maintaining vascular health through activation of MGP.