Source Naturals Vitamin K (phylloquinone) is a fat-soluble vitamin best known for its important function in the biological activity of several blood coagulation factors. Recent research has also shown a significant role for vitamin K in bone health. Vitamin K plays a key role in the synthesis of the bone proteins osteocalcin and matrix Gla-protein, which are involved in calcium and bone metabolism.*

Suitable for vegetarians. Contains no yeast, dairy, egg or soy. Contains no starch, preservatives or artificial color, flavor or fragrance.

Suggested Use: As a dietary supplement, 1 tablet daily.

Important: If you are taking anticoagulant drugs such as warfarin (Coumadin®), consult your healthcare professional before using this product, as vitamin K can interact with blood-thinning medications.

Frequently Asked Questions

What is Vitamin K used for?

Vitamin K is primarily known for its role in blood coagulation — it activates several clotting factors that allow wounds to heal. Beyond clotting, research has highlighted its important role in bone health, where it supports the production of osteocalcin and matrix Gla-protein, two proteins essential for calcium regulation and bone strength.*

What is the difference between Vitamin K1 and Vitamin K2?

Vitamin K1 (phylloquinone), found in this product, is the primary dietary form of vitamin K and is best known for its role in blood clotting. Vitamin K2 (menaquinone) is more commonly associated with bone and cardiovascular health. Source Naturals also offers a Vitamin K2 Advantage formula for those seeking K2-specific support.*

Can I take Vitamin K if I am on blood thinners?

No — if you are taking anticoagulant medications such as warfarin (Coumadin®), you should not take vitamin K supplements without first consulting your healthcare professional. Vitamin K directly influences blood clotting and can reduce the effectiveness of anticoagulant drugs, requiring careful monitoring.

Does Vitamin K support bone health?

Yes. Research has shown that vitamin K plays a vital role in bone metabolism by activating osteocalcin and matrix Gla-protein — two proteins involved in binding calcium within bone tissue. Adequate vitamin K intake is considered an important complement to calcium and vitamin D for bone density support.*