Is Vitamin K Good for Mental Health? A Deep Dive into the Nutritional Link

October 31, 2025 •

5 min read

Recent studies have revealed that patients with depressive symptoms often exhibit lower levels of vitamin K, underscoring a compelling, albeit surprising, connection between this fat-soluble vitamin and mental well-being. As the field of nutritional psychiatry expands, the nuanced role of micronutrients in supporting brain function is coming into sharper focus.

Quick Summary

This article explores the growing body of evidence linking higher vitamin K intake and status with improved mental and cognitive health, examining potential mechanisms such as reduced inflammation and enhanced neuronal function. Key dietary sources are also discussed to help support brain health.

Key Points

Inverse Association: Multiple studies have found that higher intake and blood levels of vitamin K are associated with lower rates of depression and depressive symptoms in adults.
Low Levels Linked to Suicide Risk: Research shows that depressed patients with a history of suicide attempts have notably lower serum vitamin K levels, suggesting it may be a biological risk factor.
Protection Against Inflammation: Vitamin K acts as an antioxidant and anti-inflammatory agent, protecting the brain from oxidative stress and neuroinflammation, both of which are linked to mood disorders.
Supports Neuronal Health: The vitamin is crucial for sphingolipid metabolism and activating key proteins like Gas6 and osteocalcin, which are vital for cell membranes, neuronal signaling, and neurogenesis.
Different Forms, Different Functions: Vitamin K2, particularly its MK-4 subtype, is the predominant form found in the brain, suggesting it has unique mental health benefits beyond the blood-clotting function of K1.
Promotes Cognitive Function: Post-mortem brain studies have linked higher MK-4 levels to lower odds of dementia and cognitive impairment, potentially by protecting against neurofibrillary tangles.
Improves Vascular Health: Vitamin K2 supports cardiovascular health by preventing arterial calcification, which can improve blood flow to the brain and protect against cognitive decline associated with vascular damage.
Rich Dietary Sources: Incorporate leafy greens (K1), and fermented foods, eggs, and meat (K2) into your diet to ensure adequate vitamin K intake.

The Emerging Link Between Vitamin K and Mood

While traditionally recognized for its role in blood clotting and bone health, vitamin K's potential impact on mental health has recently gained significant scientific attention. Several observational studies have reported an inverse association between vitamin K intake or serum levels and depressive symptoms across different populations. For example, a large, cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) found that U.S. adults with higher vitamin K intake had significantly lower odds of depressive symptoms. This relationship was independent of other health and lifestyle factors, suggesting a direct or semi-direct biological link.

Further supporting this connection, a 2024 retrospective study revealed that depressed patients with a history of suicide attempts had significantly lower serum vitamin K levels compared to those without. The study concluded that low vitamin K might be a biological risk factor for depression. While these observational findings suggest a strong correlation, they do not establish causation. However, they provide a solid foundation for further, more targeted research into vitamin K's therapeutic potential for mental well-being.

Potential Mechanisms for Vitamin K's Neuroprotective Effects

Research suggests several plausible mechanisms through which vitamin K, particularly the K2 isoform menaquinone-4 (MK-4), may support mental and cognitive health:

Antioxidant and Anti-Inflammatory Properties: Oxidative stress and neuroinflammation are increasingly recognized as contributing factors to the pathophysiology of depression and cognitive decline. Vitamin K acts as a potent antioxidant, protecting brain cells from damage caused by reactive oxygen species (ROS). MK-4, the predominant form of vitamin K in the brain, has been shown to reduce neuroinflammatory markers in animal models.
Regulation of Sphingolipid Metabolism: The brain is rich in sphingolipids, which are critical for cell membrane structure and neuronal signaling. Vitamin K helps regulate the enzymes involved in sphingolipid synthesis, and deficiency has been linked to impaired cognition and behavior in animal studies. By supporting proper sphingolipid balance, vitamin K may enhance neuronal function and resilience against mood disorders.
Vitamin K-Dependent Proteins: Vitamin K is required for the activation of specific proteins, including Growth Arrest-Specific 6 (Gas6) and osteocalcin. Gas6 promotes neuronal survival, growth, and myelination. Osteocalcin, a bone-derived hormone, can cross the blood-brain barrier and has been shown to boost neurogenesis, enhance learning and memory, and potentially influence mood regulation.
Vascular Health and Cerebral Perfusion: The connection between cardiovascular health and mental health is well-established. Vitamin K2 plays a key role in preventing arterial calcification, which maintains the elasticity of blood vessels and ensures proper blood flow to the brain. Improved cerebral perfusion could contribute to better cognitive function and mood regulation.

The Critical Difference Between Vitamin K1 and K2

There are two main forms of vitamin K: phylloquinone (K1) and menaquinone (K2). While both are important, they differ in their sources, absorption, and function.

Vitamin K1 (Phylloquinone): Found predominantly in plant-based foods like green leafy vegetables (e.g., spinach, kale, broccoli) and some vegetable oils.
Vitamin K2 (Menaquinone): Found in animal products (meat, eggs, cheese) and fermented foods (natto). It has a significantly longer half-life and accumulates more effectively in extrahepatic tissues, including the brain. MK-4, a subtype of K2, is the main form of vitamin K found in brain tissue.

Here is a comparison of Vitamin K1 and K2:


Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Primary Sources	Green leafy vegetables, vegetable oils	Fermented foods (natto), animal products (eggs, meat, cheese)
Absorption	Less readily absorbed from plant sources	Generally better absorbed, especially from dietary fats
Half-Life	Short	Significantly longer (especially MK-7)
Brain Concentration	Low in brain tissue	MK-4 subtype is the predominant form in the brain
Mental Health Relevance	Observational links, but likely mediated by conversion to K2	Directly implicated through MK-4's presence and function in brain tissue

How to Incorporate Vitamin K into a Mental Health Diet

Adopting a diet rich in vitamin K, particularly K2, can support overall brain health. Focusing on whole, nutrient-dense foods is key.

Leafy Greens: Load up on spinach, kale, collard greens, and other leafy vegetables. A single cup of cooked kale can provide hundreds of micrograms of vitamin K1.
Fermented Foods: Natto, a fermented soybean dish, is an exceptionally rich source of K2 (MK-7). Other fermented dairy products like certain cheeses also contain K2.
Animal Products: Include eggs, chicken, and some dairy products in your diet to boost your intake of the K2 (MK-4) form.
Pair with Healthy Fats: Since vitamin K is fat-soluble, consuming it with a source of healthy fat, like olive oil or avocado, can enhance absorption.

Understanding the Research Limitations and Future Directions

While the evidence is promising, several limitations exist in the current body of research. Many studies on vitamin K and mental health are observational, meaning they can identify associations but cannot prove cause and effect. More randomized controlled trials (RCTs) are needed to confirm the efficacy of vitamin K supplementation, especially to differentiate the effects of K1 versus K2 and their specific impact on mood disorders. Researchers also need to further clarify the exact biological mechanisms and pathways through which vitamin K influences brain function. For individuals with specific health conditions or those taking certain medications, like blood thinners, consultation with a healthcare provider is essential before considering supplementation.

Conclusion

While vitamin K is not a cure-all, the growing body of research suggests a significant and multifaceted role in supporting mental and cognitive health. From its antioxidant and anti-inflammatory effects to its involvement in key brain proteins and vascular function, maintaining adequate vitamin K levels, particularly the K2 isoform, appears to be a worthwhile dietary strategy. The link between a healthy diet and mental well-being is undeniable, and prioritizing vitamin K-rich foods can be a valuable part of a holistic approach to supporting your mind. As science continues to uncover the intricate nutritional ties to our mental state, the simple act of choosing nutrient-dense foods remains a powerful tool for wellness. To explore the broader context of how nutrition affects the brain, you can learn more about nutritional psychiatry and its guiding principles.

Learn more about nutritional psychiatry

Frequently Asked Questions

Vitamin K may aid mental health by reducing brain inflammation and oxidative stress, regulating brain cell metabolism through sphingolipids, and activating proteins like osteocalcin and Gas6, which are involved in neuronal growth and mood regulation.

Yes, several observational studies have found an inverse relationship, suggesting that lower levels of vitamin K may be linked to an increased prevalence of depressive symptoms. Case-control studies have also linked low serum vitamin K levels to suicidal attempts in depressed patients.

While both are important, K1 is primarily for blood clotting, and K2, especially the MK-4 subtype, is the main form stored in the brain. The MK-4 found in the brain may be responsible for the specific neuroprotective effects linked to better cognitive function and mental well-being.

To support mental health, focus on sources of both K1 and K2. Excellent sources of K1 include kale, spinach, and broccoli, while K2 can be found in fermented foods like natto, as well as eggs, meat, and certain cheeses.

While some animal studies and a small clinical trial have shown improvements in mood with K2 supplementation, more research, particularly large-scale human randomized controlled trials, is needed to confirm this effect. It is important to consult a doctor before taking supplements.

Yes, evidence from human and animal studies suggests a positive link. Post-mortem studies show higher brain vitamin K2 (MK-4) concentrations are associated with a lower risk of dementia and mild cognitive impairment. Animal models also show that deficiency impairs learning and memory.

For most people, getting vitamin K through diet is safe and recommended. However, those taking blood-thinning medications like warfarin should not change their vitamin K intake without consulting a doctor, as it can interfere with their medication. High doses are not recommended without medical supervision.