Understanding if and How Does Vitamin K2 Help with Blood Circulation?

October 21, 2025 •

4 min read

According to research from the Rotterdam Study, a diet high in vitamin K2 is associated with a significantly lower risk of coronary heart disease. This discovery has led to increased interest in how does vitamin K2 help with blood circulation, particularly its unique function beyond the well-known role of vitamin K in blood clotting. The key lies in its ability to manage calcium in the body, ensuring it goes to the right places, like bones, and stays out of soft tissues, such as arteries.

Quick Summary

This article explores the mechanisms by which vitamin K2 supports healthy blood circulation by activating proteins that prevent arterial calcification. It compares the distinct roles of vitamin K1 and K2, highlights the superior bioavailability of K2, and discusses its primary dietary sources and synergistic relationship with vitamin D3.

Key Points

Activates Matrix Gla Protein (MGP): Vitamin K2 activates MGP, a protein that actively inhibits calcium buildup in arteries, preventing arterial stiffening and calcification.
Improves Arterial Elasticity: By preventing calcification, K2 helps maintain the flexibility and elasticity of blood vessels, which promotes healthy blood flow.
Longer Half-Life than K1: The MK-7 subtype of K2 has a much longer half-life than K1, allowing it to work more effectively in extrahepatic tissues like the arteries.
Synergistic with Vitamin D3: K2 works with Vitamin D3 to ensure calcium is deposited in bones and not in arteries, optimizing both skeletal and cardiovascular health.
Reduced Cardiovascular Risk: Observational studies have shown that a higher intake of vitamin K2 is associated with a reduced risk of coronary heart disease and cardiovascular mortality.
Found in Fermented and Animal Foods: Good dietary sources of K2 include natto, certain cheeses, egg yolks, and liver, which are often lacking in a typical Western diet.

The Mechanism Behind Vitamin K2 and Arterial Health

At the heart of vitamin K2's role in blood circulation is its ability to regulate calcium. Calcium is essential for building strong bones, but when it accumulates in arteries, it can lead to stiffening and calcification, which are major risk factors for cardiovascular disease. Vitamin K2 acts as a biological traffic controller for calcium through its activation of specific proteins.

How Matrix Gla Protein (MGP) Prevents Calcification

One of the most critical proteins activated by vitamin K2 is Matrix Gla Protein (MGP). Produced by vascular smooth muscle cells, MGP functions as a potent inhibitor of soft tissue calcification. When vitamin K2 is sufficient, MGP is activated and effectively prevents calcium from depositing in the artery walls. In contrast, a deficiency of vitamin K2 leaves MGP in an inactive state, allowing calcium to accumulate and form calcified plaques that harden the arteries. This hardening, known as atherosclerosis, is a primary cause of poor blood circulation and increased cardiovascular risk.

A Tale of Two Vitamins: K1 vs. K2

While both K1 (phylloquinone) and K2 (menaquinones) are part of the vitamin K family, they play different physiological roles. Vitamin K1, primarily found in leafy green vegetables, is mainly involved in liver-based coagulation processes. Vitamin K2, conversely, is a key player in extrahepatic tissues, including the arterial walls. This difference is largely due to their bioavailability and half-life.

Bioavailability and Tissue Distribution

Research indicates that the body absorbs vitamin K2 (especially the MK-7 subtype) more readily and it remains in circulation much longer than K1, allowing it to be more effectively utilized by extrahepatic tissues like blood vessels. This prolonged availability is crucial for its anti-calcification function.

Comparing Vitamin K1 and K2


Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Primary Role	Blood coagulation (clotting) factors in the liver.	Calcium regulation in extrahepatic tissues, bone, and arteries.
Main Sources	Leafy green vegetables (spinach, kale), some plant oils.	Fermented foods (natto, sauerkraut), animal products (cheese, eggs, liver).
Tissue Concentration	Primarily concentrated in the liver.	Widely distributed in bones, kidneys, and arteries.
Half-Life	Short half-life, staying in the blood for only a few hours.	Longer half-life (MK-7 can last for days), offering more sustained effects.
Cardiovascular Impact	Less direct impact on arterial health, primarily due to poor extrahepatic distribution.	Significant role in preventing arterial calcification and improving vascular elasticity.

The Synergy of Vitamin K2 and Vitamin D3

The relationship between vitamin K2 and vitamin D3 is a crucial aspect of mineral metabolism. Vitamin D3 promotes the absorption of calcium from the gut, but it is vitamin K2 that directs this calcium to its proper destination: the bones and teeth. Without sufficient K2, excess calcium absorbed via D3 may build up in the arteries, exacerbating vascular calcification. Therefore, taking these two fat-soluble vitamins together is considered a synergistic strategy for both bone and cardiovascular health.

Key Dietary Sources of Vitamin K2

Vitamin K2 is less common in Western diets than K1. The best sources include:

Natto: A traditional Japanese fermented soybean dish, natto is exceptionally high in the bioavailable MK-7 subtype of K2.
Fermented Foods: Other fermented products, such as sauerkraut and certain types of cheese (Gouda, Edam), also contain significant amounts of K2.
Animal Products: The MK-4 subtype is found in fatty animal products. These include:
- Egg yolks
- Goose liver
- Organ meats
- Grass-fed butter and dairy

Research Supporting K2's Impact on Blood Circulation

Numerous studies have investigated the link between vitamin K2 and cardiovascular health. The landmark Rotterdam Study found a strong inverse correlation between high menaquinone intake and mortality from coronary heart disease. Another clinical study on postmenopausal women with low vitamin K status showed that supplementation with menaquinone-7 (MK-7) significantly improved arterial elasticity and reduced arterial stiffening over a one-year period. These findings indicate a promising role for K2 in actively improving the health and function of blood vessels.

Precautions and Expert Recommendations

While vitamin K2 is generally safe, it is critical to consult a healthcare professional before taking supplements, especially for those on blood-thinning medication like warfarin. Vitamin K's involvement in blood clotting can interfere with these medications. For individuals not on such medication, research suggests that supplementing with K2 (particularly MK-7) can be a safe and effective way to support cardiovascular health. As more long-term controlled trials are needed to confirm the full extent of its benefits, maintaining a balanced intake through diet is a reliable approach for overall health.

Conclusion

In summary, the answer to does vitamin K2 help with blood circulation? is a resounding yes. Through its ability to activate MGP and regulate calcium, vitamin K2 plays a vital role in preventing arterial calcification, which is fundamental for maintaining flexible and healthy blood vessels. By supporting arterial elasticity, it helps regulate blood pressure and enhances overall blood flow, offering substantial benefits for long-term cardiovascular health. Increasing dietary intake of K2-rich foods or considering supplementation (with professional guidance) can be a proactive step towards optimizing vascular function.

Reference: For more on the physiological roles of vitamin K, see the Linus Pauling Institute fact sheet on Vitamin K: https://lpi.oregonstate.edu/mic/vitamins/vitamin-K.

Frequently Asked Questions

Vitamin K2 activates Matrix Gla Protein (MGP), a potent inhibitor of soft tissue calcification. Activated MGP binds to calcium and prevents it from depositing in the walls of the arteries, which keeps them flexible and healthy.

While both are important for overall health, vitamin K1's primary role is in blood coagulation in the liver. Vitamin K2 has a more direct and potent effect on cardiovascular health and blood circulation due to its better bioavailability and longer half-life, allowing it to concentrate in extrahepatic tissues like arteries.

The richest source of vitamin K2 (specifically MK-7) is natto, a Japanese fermented soybean dish. Other good sources include fermented foods like sauerkraut, hard cheeses (Gouda, Edam), and animal products such as egg yolks, liver, and grass-fed butter.

By preventing arterial calcification and stiffening, vitamin K2 helps maintain the elasticity of blood vessels. This improved arterial flexibility can help regulate blood pressure and reduce the strain on the heart, contributing to better blood pressure control.

Vitamin K2 and Vitamin D3 work synergistically. Vitamin D3 increases the body's absorption of calcium, while vitamin K2 ensures that this calcium is directed to the bones, where it is needed. This prevents the calcium from accumulating in soft tissues like arteries.

Individuals taking blood-thinning medications, such as warfarin, should not take vitamin K2 supplements without first consulting a healthcare provider. Vitamin K can interfere with these medications due to its role in blood clotting.

Vitamin K2 is generally considered safe, and no toxicity has been reported even with higher doses. However, mild digestive issues or allergic reactions can occur, and it is vital to discuss supplementation with a doctor, especially if on medication.