Does vitamin K2 decalcify arteries? Separating fact from hype

October 22, 2025 •

4 min read

According to the Rotterdam Study, a 10-year population-based study, diets rich in Vitamin K2 were associated with a 50% reduction in arterial calcification and cardiovascular-related death. This has sparked great interest in the question: does vitamin K2 decalcify arteries and reverse existing plaque?

Quick Summary

Vitamin K2, particularly the MK-7 form, activates Matrix Gla Protein (MGP), which inhibits vascular calcification. While strong evidence supports its role in preventing and slowing the progression of arterial hardening, the ability to reverse existing calcification is still being investigated, with some promising but not definitive results.

Key Points

Inhibits Calcification Progression: Vitamin K2 activates Matrix Gla Protein (MGP), a potent inhibitor of vascular calcium buildup, thereby helping to slow the hardening of arteries.
Reversal Potential Under Investigation: While K2 is effective at preventing calcification progression, evidence for reversing existing, severe calcification is still emerging, though some studies show promise in restoring arterial elasticity.
MK-7 Form is Superior: The MK-7 form of vitamin K2 has a longer half-life and greater bioavailability than MK-4, making it more effective for targeting extra-hepatic tissues like arteries.
Works with Vitamin D3: For optimal calcium metabolism, vitamin K2 works synergistically with vitamin D3. D3 helps absorb calcium, while K2 activates the proteins that direct it properly.
Best Dietary Sources: Fermented foods like natto are excellent sources of K2. Other good options include certain hard cheeses, egg yolks, and goose liver.
Medical Consultation is Key: Individuals on blood-thinning medication (e.g., warfarin) must consult their doctor before taking vitamin K2 supplements due to potential drug interactions.

Understanding Arterial Calcification

Arterial calcification, or the hardening of arteries, is a significant risk factor for cardiovascular disease. It involves the buildup of calcium phosphate crystals within the walls of blood vessels, contributing to arterial stiffness and narrowing. This process can severely impair blood flow and increase the risk of serious cardiac events like heart attacks. Unlike bone, where calcium is a necessary component for strength, calcium deposits in soft tissues like arteries are highly problematic. For decades, the medical community has focused on managing traditional risk factors like cholesterol, blood pressure, and inflammation. However, research into the role of specific nutrients, particularly vitamin K2, has shed new light on the mechanisms governing calcium's distribution in the body.

The Role of Vitamin K2: Mechanism of Action

At the heart of vitamin K2's function is its ability to activate specific proteins through a process called carboxylation. One of the most important of these proteins is Matrix Gla Protein, or MGP. MGP is a potent inhibitor of soft-tissue calcification and is found in high concentrations within the walls of blood vessels. When vitamin K2 levels are sufficient, MGP becomes activated and patrols the arterial walls, binding to calcium and preventing it from depositing. In a state of vitamin K deficiency, MGP remains inactive, allowing calcium to accumulate in the arteries unchecked. This mechanism is a key reason why vitamin K2 is a crucial player in maintaining vascular health.

The Synergy with Vitamin D

Vitamin K2 does not work in isolation. Its function is intimately linked with vitamin D3, a nutrient essential for calcium absorption. While vitamin D3 is responsible for regulating the production of calcium-transporting proteins like MGP, vitamin K2 is the critical cofactor that activates them. Without adequate K2, the calcium absorbed with the help of vitamin D can be misdirected to soft tissues, including arteries. Therefore, ensuring sufficient levels of both vitamins is essential for proper calcium metabolism, directing it to bones for strength and keeping it out of the arteries.

MK-4 vs. MK-7: Not All K2 is Equal

Vitamin K2 exists in several forms, known as menaquinones (MKs). The two most commonly studied forms are MK-4 and MK-7, which differ significantly in their bioavailability and half-life.


Feature	MK-4	MK-7	Comparison for Arterial Health
Source	Found in animal products like meat, eggs, and dairy.	Produced by bacteria during fermentation; abundant in natto.	MK-7 from natto is a far more reliable dietary source.
Half-Life	Short half-life (a few hours).	Long half-life (over 3 days).	MK-7's longer presence in the body makes it more effective for extra-hepatic tissues like arteries.
Dosing	Requires larger, more frequent doses for efficacy.	Effective at much lower, once-daily doses.	MK-7 is more practical for supplementation for cardiovascular benefits.
Primary Function	Liver-focused; involved in coagulation.	Extra-hepatic focus; potent activator of MGP in arteries.	MK-7 specifically targets the extra-hepatic calcification relevant to heart health.

Given MK-7's superior bioavailability and longer half-life, it is the form most often studied and recommended for targeted cardiovascular benefits.

Can Vitamin K2 Decalcify Existing Arterial Plaque?

The answer to this question is nuanced. The evidence is much stronger for vitamin K2's ability to inhibit or slow the progression of calcification rather than actively reversing existing hardened plaque.

Evidence for Inhibition and Slowing Progression: Numerous studies, including observational ones like the Rotterdam Study, show a correlation between higher K2 intake and a reduced risk of cardiovascular disease and arterial calcification progression. Clinical trials have also shown that K2 supplementation can reduce the rate of progression in individuals with pre-existing calcification.
Evidence for Reversal: Some studies, though fewer in number, have suggested a potential for reversal. A notable 2015 study demonstrated that K2 supplementation led to an improvement in arterial elasticity and regression of age-related arterial stiffening in certain participants. Other studies have also shown improvements in markers like carotid-femoral pulse-wave velocity, an indicator of arterial flexibility. However, findings from the AVADEC trial showed no significant effect on aortic valve calcification progression, highlighting the need for more large-scale, long-term studies to confirm reversal capabilities.

Dietary Sources and Supplementation

To boost your vitamin K2 intake, focusing on specific foods is key. The best source by far is natto, a fermented Japanese soybean product, which contains exceptionally high levels of the MK-7 form. Other good sources of K2 include:

Certain cheeses (e.g., Munster, Gouda, and Brie)
Goose liver and other organ meats
Egg yolks from pasture-raised chickens
Fermented foods like sauerkraut

For many, achieving optimal K2 intake through diet alone can be challenging due to the limited number of common foods rich in this nutrient. In such cases, supplementation with K2, often in combination with D3, is a practical option. However, it's crucial to consult a healthcare provider before starting any new supplement, especially if you are on blood thinners like warfarin, as vitamin K can interfere with their action.

Conclusion: The Path Forward

While the idea that vitamin K2 can completely decalcify arteries is an oversimplification, the evidence overwhelmingly supports its critical role in inhibiting the progression of vascular calcification. By activating MGP, K2 helps prevent calcium from settling in soft tissues and directs it towards bone, particularly in synergy with vitamin D3. While some studies show promising signs regarding the potential for reversal, especially in high-risk individuals and in improving arterial elasticity, more research is needed for definitive conclusions. The consensus points to K2 being a valuable nutritional tool for preventing the advancement of arterial disease. A diet rich in K2-containing foods, coupled with a healthy lifestyle, offers a proactive approach to cardiovascular wellness. For those considering supplementation, professional medical advice is essential.

Learn more about the science of Vitamin K2 for heart health.

Frequently Asked Questions

The primary mechanism is the activation of Matrix Gla Protein (MGP). Vitamin K2 acts as a cofactor to carboxylate MGP, which then binds to calcium and prevents it from depositing in the artery walls.

The evidence is strongest for K2's ability to inhibit the progression of arterial calcification. While some research suggests potential for improving arterial elasticity, conclusive evidence for actively reversing significant existing plaque is still being gathered.

Vitamin K1 (phylloquinone) is primarily involved in blood clotting in the liver. Vitamin K2 (menaquinones), especially the MK-7 form, is more effective at activating extra-hepatic proteins like MGP, which inhibit arterial calcification.

For cardiovascular health, the MK-7 form is generally recommended due to its superior bioavailability and longer half-life, allowing it to effectively reach and act on arterial tissues.

Yes, natto (a traditional Japanese fermented soybean dish) is an exceptionally rich source of MK-7. Other notable sources include certain cheeses (e.g., gouda, edam) and goose liver.

Vitamin D helps the body produce calcium-regulating proteins like MGP, while vitamin K2 is necessary to activate those proteins. They are a synergistic pair, ensuring calcium is directed to bones rather than arteries.

No. It is essential to consult with your healthcare provider before taking any vitamin K supplement, including K2, if you are on blood-thinning medication like warfarin. Vitamin K directly interferes with these drugs.