Does Vitamin K Reduce Inflammation? An In-Depth Look

November 15, 2025 •

3 min read

Recent research from a study involving over 36,000 participants found that higher vitamin K intake was associated with lower inflammatory status and improved immune markers. This growing body of evidence suggests that vitamin K may possess anti-inflammatory properties, with potential implications for chronic disease management.

Quick Summary

This article examines the scientific basis for vitamin K's anti-inflammatory effects. It explores the mechanisms by which vitamin K may modulate inflammatory pathways and discusses the different forms of this fat-soluble vitamin. A comprehensive overview of current research, including human and animal studies, is provided, along with dietary recommendations.

Key Points

Inhibits NF-κB Signaling: Vitamin K suppresses the NF-κB pathway, a central regulator of inflammation, reducing the production of pro-inflammatory cytokines like IL-6 and TNF-α.
Acts as an Antioxidant: Vitamin K demonstrates potent antioxidant properties, protecting against oxidative stress by scavenging reactive oxygen species and reinforcing cellular defenses.
Differs by Vitamin Form: Both vitamin K1 and K2 show anti-inflammatory effects, but K2, found in fermented foods and animal products, has been particularly noted for its potency in some studies.
Supported by Observational Data: Many population-based studies link higher vitamin K levels with lower levels of inflammatory markers such as CRP and IL-6.
Beneficial for Chronic Conditions: The anti-inflammatory effect is considered most relevant for chronic age-related diseases like cardiovascular disease and osteoarthritis, which are driven by low-grade inflammation.
Best Sourced from Diet: Incorporating a diverse diet rich in leafy greens (K1) and fermented foods or some animal products (K2) is the best way to ensure adequate intake.

The Anti-Inflammatory Potential of Vitamin K

Inflammation is a fundamental immune response, but when it becomes chronic, it can contribute to a wide range of diseases, including cardiovascular disease, type 2 diabetes, and osteoarthritis. Scientific inquiry suggests that vitamin K may help regulate this inflammatory process. Evidence from various studies indicates that vitamin K, particularly vitamin K2, has anti-inflammatory properties by modulating cellular signaling and reducing oxidative stress.

How Vitamin K Modulates Inflammation

Vitamin K's role in inflammation is distinct from its blood coagulation function. A key mechanism identified is its ability to suppress the nuclear factor kappa-B (NF-κB) signaling pathway. NF-κB is a protein complex controlling genes involved in inflammatory responses. By inhibiting this pathway, vitamin K can reduce the production of pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α).

Vitamin K also acts as an antioxidant. Reactive oxygen species (ROS) contribute to oxidative stress, which promotes inflammation. Vitamin K has been shown to block ROS generation and act as an antioxidant, sometimes more potent than vitamin E.

Suppresses Pro-Inflammatory Cytokines: Vitamin K, especially K2, may reduce levels of IL-6 and TNF-α.
Inhibits NF-κB Pathway: Suppressing NF-κB prevents activation of inflammatory genes.
Reduces Oxidative Stress: Vitamin K helps protect cells from oxidative damage.

The Difference Between Vitamin K1 and K2

There are two main dietary forms: phylloquinone (K1) and menaquinone (K2). Both show anti-inflammatory potential, but their sources and effects differ.


Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Sources	Green leafy vegetables, vegetable oils.	Fermented foods, animal products, gut bacteria.
Primary Role	Liver-based blood coagulation.	Extrahepatic tissues (bones, arteries, immune cells).
Bioavailability	Absorbed less efficiently than K2.	More bioavailable, longer half-life than K1.
Anti-Inflammatory Action	Associated with lower inflammatory markers in some studies; intervention study results vary.	May show more potent effects in some models, acting through NF-κB inhibition.
Clinical Evidence	Inverse correlation with markers like CRP and IL-6 in some studies.	Emerging evidence for a protective role against age-related inflammation, particularly cardiovascular and bone health.

Clinical Evidence and Research Status

Observational studies often show an inverse relationship between vitamin K status and inflammatory markers like IL-6 and C-reactive protein (CRP). However, randomized controlled trials have had less consistent results, particularly in healthy populations. Some researchers suggest effects might be more pronounced in individuals with higher inflammation or conditions like diabetes or osteoarthritis. An analysis of NHANES data found a negative correlation between vitamin K intake and several inflammatory indicators.

Incorporating Vitamin K for Anti-Inflammatory Benefits

To potentially benefit from vitamin K's anti-inflammatory effects, include diverse dietary sources. As it's fat-soluble, consume these foods with healthy fats to enhance absorption.

Leafy greens: Include kale, spinach, and collard greens.
Cruciferous vegetables: Broccoli, Brussels sprouts, and cabbage are good sources.
Fermented foods for K2: Consider natto or some aged cheeses.
Include healthy fats: Cook greens with healthy oils like soybean or canola oil.
Animal products: Include moderate amounts of eggs, chicken, and beef liver for K2.

Conclusion

Evidence from various studies suggests vitamin K has anti-inflammatory properties by inhibiting the NF-κB pathway and reducing oxidative stress. Both K1 and K2 contribute to this effect, with distinct sources. While clinical trial results for supplementation vary, maintaining adequate vitamin K through diet appears to offer protection, especially for age-related inflammatory conditions. A varied diet rich in both K1 and K2 is recommended to support health and potentially mitigate chronic inflammation.

For more detailed scientific reviews, see the publication from MDPI on the role of Vitamin K in aging.

Frequently Asked Questions

While both vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) have anti-inflammatory effects, some in-vitro and animal studies suggest K2 might be more potent due to its higher bioavailability and longer half-life. However, getting a balanced intake of both from a varied diet is recommended.

Some cross-sectional studies show an inverse correlation between vitamin K status and circulating C-reactive protein (CRP), a marker of inflammation. However, some randomized controlled trials have not consistently shown that supplementation significantly lowers CRP, especially in generally healthy individuals. The effect may be more noticeable in people with higher inflammatory burdens.

For natural vitamin K1 and K2, adverse effects are rare, and no Tolerable Upper Intake Level has been established for these forms. However, individuals on blood-thinning medication like warfarin must manage their vitamin K intake carefully under a doctor's supervision, as it can interfere with its action.

Foods rich in vitamin K1 include leafy greens like kale and spinach, as well as broccoli and Brussels sprouts. For vitamin K2, sources include natto (fermented soybeans), eggs, and some cheeses.

Cooking methods can sometimes affect vitamin concentration. For vitamin K, some studies suggest that boiled, frozen vegetables might concentrate the vitamin due to water loss, while raw consumption also provides excellent amounts. As vitamin K is fat-soluble, consuming it with some fat can enhance absorption.

No, the anti-inflammatory effects of vitamin K appear to be independent of its well-known role as an enzymatic cofactor for blood clotting. The anti-inflammatory mechanism involves suppressing the NF-κB signaling pathway and providing antioxidant protection.

Evidence suggests a link between low vitamin K status and a higher prevalence or progression of osteoarthritis. The anti-inflammatory properties of vitamin K may help mitigate the inflammatory component of this condition, although more clinical trials are needed to confirm the therapeutic efficacy of supplementation specifically for osteoarthritis.