Is vitamin K2 safe to use in patients with a history of Deep Vein Thrombosis (DVT)?

From the Guidelines

Vitamin K2 supplementation is considered safe for patients with a history of Deep Vein Thrombosis (DVT) when used under medical supervision, especially for those on direct oral anticoagulants (DOACs) like apixaban or rivaroxaban, as recommended by recent guidelines 1. When considering vitamin K2 supplementation for patients with a history of DVT, it's crucial to understand the distinction between vitamin K1 and K2. Vitamin K1 primarily affects blood clotting, whereas vitamin K2 influences calcium metabolism by activating proteins that direct calcium to bones rather than arteries. However, for patients taking warfarin (Coumadin), a vitamin K antagonist (VKA), vitamin K2 supplements should be avoided without medical supervision, as they could potentially reduce the effectiveness of warfarin 1. For patients on DOACs, the interaction with vitamin K2 is less concerning, but typical supplemental doses ranging from 45-180 mcg daily for MK-7 should still be approached with caution and under the guidance of a healthcare provider. The decision to use vitamin K2 supplementation should be individualized based on the patient's specific medical history, current medications, and risk factors for recurrent thrombosis, prioritizing the use of anticoagulant therapies like apixaban, dabigatran, edoxaban, or rivaroxaban over VKA for treatment-phase anticoagulant therapy, as per the latest guidelines 1. Key considerations include:

• The patient's current anticoagulant therapy and potential interactions with vitamin K2
• The individual's risk factors for recurrent thrombosis
• The importance of medical supervision for safe supplementation
• The preference for DOACs over VKA in patients with VTE, as supported by recent evidence 1

From the Research

Vitamin K2 and Deep Vein Thrombosis (DVT)

• The safety of using vitamin K2 in patients with a history of Deep Vein Thrombosis (DVT) is a concern due to its potential interaction with anticoagulant therapy 2.
• A study using a rat aorta loop model found that high doses of vitamin K2 can reduce the effect of warfarin on thrombosis, but does not enhance the occurrence of thrombosis more than that without warfarin treatment 2.
• Vitamin K2 is a fat-soluble vitamin that plays a crucial role in hemostasis, and its deficiency can lead to bleeding disorders 3.
• The use of vitamin K in patients on anticoagulant therapy is a practical guide for managing over-anticoagulation, and vitamin K2 may be used to reverse excessive anticoagulation 4.

Anticoagulation Therapy for DVT

• Anticoagulation therapy is the cornerstone of treatment for acute vein thrombosis (DVT) and aims to reduce symptoms, thrombus extension, DVT recurrences, and mortality 5.
• Non-Vitamin K antagonists oral anticoagulants (NOACs) are considered first-line therapy for DVT and are recommended as the preferred anticoagulant agents by most scientific societies 5.
• The treatment of distal DVT is not clearly established, but anticoagulation therapy with a vitamin K antagonist (VKA) can reduce the risk of recurrent venous thromboembolism (VTE) and DVT 6.

Interaction between Vitamin K2 and Anticoagulant Therapy

• Vitamin K2 can interact with warfarin, a vitamin K antagonist, and reduce its effect on thrombosis 2.
• The use of vitamin K2 in patients on warfarin therapy requires careful monitoring of international normalized ratio (INR) levels to avoid over-anticoagulation or under-anticoagulation 4.
• Vitamin K2 may be used to reverse excessive anticoagulation in patients on warfarin therapy, but its effectiveness and safety in this setting are not well established 4.