By Heidi Moretti, MS, RD, CLT | Registered Dietitian, 25+ Years Clinical Experience | Updated June 2025
Is it really possible to prevent — or even reverse — atherosclerosis with a single nutrient? After more than 25 years of clinical practice as a registered dietitian, my answer is a qualified, research-backed yes — and vitamin K2 is at the center of the story.
I want to be honest with you from the start: this is not just a nutrient I write about. It is one I personally recommend in clinical practice, and the science behind it has continued to grow dramatically since I first published this post. The most recent 2025 trial data — which I walk you through below — is some of the most compelling cardiovascular nutrition evidence I have seen in my career.
Let me share what I know, what the newest research shows, and why I think vitamin K2 deserves a place in your heart health strategy.
- How atherosclerosis is tied to calcification
- Risks of arterial calcification
- How vitamin K2 activates arterial protection (the MGP mechanism)
- 5 key MenaQ7 clinical trials reviewed
- Breakthrough 2024–2025 research
- My personal clinical experience
- Key risk factors that drive a high CAC score
- Best food sources of vitamin K2
- Dosing guidance
- Frequently asked questions
How Is Atherosclerosis Tied to Calcification?
When arteries become calcified, they literally become bone-like — rigid, prone to cracking, and dangerously narrowed. This is what we call atherosclerosis: the hardening of the arteries. And it is far more than a cosmetic or age-related inconvenience.
Cardiovascular diseases (CVDs) are the number one cause of death globally, according to the World Health Organization. One of the most insidious contributors to this toll is the silent, slow process of arterial calcification. Plaque — primarily composed of calcium — builds up on artery walls over years or decades, quietly narrowing the passage for blood flow until one day the consequences become impossible to ignore.
Atherosclerosis can affect arteries anywhere in the body, leading to distinct clinical conditions based on location:
What Are the Risks of Arterial Calcification?
Bones should be calcified. Your arteries, muscles, nerves, and breast tissue should not. This misplacement of calcium — called ectopic calcification — is where so much chronic disease starts.
For many years, I worked with one of the most vulnerable clinical populations: patients with end-stage kidney disease on dialysis therapy. We had a phrase for this group: “bones of china, hearts of stone.” Their hearts and blood vessels became progressively calcified while, tragically, their bones weakened. Witnessing this taught me viscerally — not just academically — how devastating ectopic calcification can be. And it made me a committed student of anything that might interrupt that process.
Beyond the obvious heart attack risk, calcification carries broader consequences that surprised even me when I first reviewed the data:
- Stroke risk: Carotid calcification is directly tied to elevated stroke risk
- Depression: Arterial calcification, especially in men, is linked to depression and mood disorders
- Dementia: The 15-year Cardiovascular Health Study Cognition Study found arterial stiffness significantly increased dementia risk
- Vision loss: FLEMENGHO study data linked eye arterial health to MGP — vitamin K2’s key biomarker
- Breast tissue calcification: Research in AJR links breast tissue calcification to increased heart disease risk
How Vitamin K2 Activates Your Body’s Natural Artery Protector
Here is the mechanism that I think every person over 40 should understand: your body already produces a powerful anti-calcification protein called Matrix Gla Protein (MGP). It is arguably the most potent natural inhibitor of arterial calcification known to science. The problem? It only works when it is activated — and the activation switch is vitamin K2.
When MGP is inactive, it not only fails to block calcium — it actually stimulates vascular smooth muscle cells to promote calcification. This creates a self-reinforcing spiral toward atherosclerosis.
What makes vitamin K2 remarkable — and what I explain to every client who asks me about cardiovascular nutrition — is that no other drug or nutrient has been shown to impact arterial and soft tissue calcification the way K2 does. This is not a fringe claim; it is a statement that has appeared in peer-reviewed cardiovascular literature and been reinforced by clinical trial data through 2025.
Vitamin K2 may also reduce the risk of artery narrowing in the limbs (peripheral artery disease) and reduce coronary calcification risk in postmenopausal women through dietary intake alone. Animal data also confirms that vitamin K2 prevents atherosclerosis in rabbits.
5 Key MenaQ7 Clinical Trials: What the Research Actually Shows
MenaQ7 is a patented, highly bioavailable form of vitamin K2 as MK-7. It is the most clinically documented form of K2 for cardiovascular outcomes. Here are five trials I consider foundational:
In this landmark double-blind study, 244 postmenopausal women received either MenaQ7 at 180 mcg/day or placebo for three years. Women receiving vitamin K2 showed significantly reduced arterial stiffness compared to placebo. The benefit was most pronounced in women with the worst arterial function at baseline — suggesting vitamin K2 may not only prevent but help reverse existing arterial stiffness. Arterial stiffness is measured via pulse wave velocity, a non-invasive and reliable marker of calcification.
53 patients with kidney failure on hemodialysis received either 135 mcg or 360 mcg of MenaQ7 daily. Notably, nearly all patients were vitamin K2 deficient at baseline. Supplementation improved key vitamin K2 blood markers — active MGP, active osteocalcin, and PIVKA-II — by 77% and 93% in the two dose groups respectively. This confirmed that even short-term supplementation can significantly restore K2 status in deficient patients.
Sixty patients after kidney transplants received MenaQ7 before and after surgery. The result was improved vitamin K2 levels and meaningfully reduced arterial stiffness. This is particularly meaningful because post-transplant patients face accelerated cardiovascular risk.
Fifty hemodialysis patients received 360 mcg of MenaQ7 daily for just four weeks. Vitamin K2 blood markers improved significantly, and dephosphorolated uncarboxylated MGP (the most sensitive marker of K2 insufficiency) was directly correlated with calcification progression.
Patients with advanced CKD received 90 mcg of MenaQ7 plus vitamin D3 or vitamin D3 alone for 270 days. The K2+D3 combination produced reduced atherosclerosis progression and reduced arterial stiffness. The effect was strongest in K2-deficient patients. This trial also demonstrated the synergy between vitamin K2 and D3 — a pairing that continues to generate important research.
Breakthrough 2024–2025 Research: The Science Is Accelerating
Since the original publication of this post, the research on vitamin K2 and cardiovascular health has expanded significantly. Here is what the most recent evidence shows — and why I find it so compelling.
This highly anticipated randomized, double-blind, placebo-controlled trial tested MenaQ7 MK-7 in patients with mild-to-moderate coronary artery calcification. After two years of supplementation, MK-7 was able to significantly slow the rate of coronary artery calcification progression — arresting CAC progression by 22% in participants with mild-to-moderate coronary artery disease. Levels of dp-ucMGP (inactive MGP — the key deficiency marker) rose significantly less in the treated group, confirming the mechanism. This is the clearest human evidence yet that supplemental K2 can meaningfully interrupt the calcification cascade in the heart’s own arteries.
A post-hoc analysis published in Nutrients (February 2025) examined pre-, peri-, and postmenopausal women with low vitamin K2 status. Women with high baseline vascular stiffness who received one year of MK-7 supplementation showed significant reductions in arterial stiffness and — for the first time in the literature — improved blood pressure in both brachial and carotid arteries. The placebo group showed the opposite: women with high baseline stiffness became significantly worse. Read the study here.
The Aortic Valve Decalcification Trial (AVADEC), published in JACC, tested 720 mcg/day of MK-7 plus 25 mcg/day vitamin D in men with high aortic valve calcification scores. While no significant effect was observed on the primary outcome in the total group, a subgroup of high-risk participants showed significantly slowed CAC progression with the K2+D3 combination over two years. This study highlights both the potential and the complexity of targeting established calcification with nutrition — and emphasizes that those with the greatest deficiency have the most to gain.
A 2025 case-control study from Taibah University investigated serum MK-4 and MK-7 levels in patients with confirmed coronary artery disease versus controls. Results confirmed a significant association between low vitamin K2 status and CAD risk factors, adding to the growing epidemiological case for K2 as a cardiovascular biomarker.
A comprehensive systematic review and meta-analysis published in January 2024 in the Journal of Nutritional Science synthesized the available randomized controlled trial data on vitamin K supplementation and cardiovascular risk factors. The analysis confirmed vitamin K’s beneficial role in reducing cardiovascular risk markers, lending meta-level weight to the individual trial findings reviewed above.
My Personal Clinical Experience With Vitamin K2
Over 25 years of clinical nutrition practice, I have watched the evidence on vitamin K2 grow from a curiosity to a genuine cardiovascular priority. My early clinical work with dialysis patients — the “bones of china, hearts of stone” population I mentioned above — gave me a front-row seat to what happens when calcification runs unchecked. We had almost no nutritional tools to offer those patients at the time. Understanding the K2-MGP connection changed that perspective for me permanently.
In my functional nutrition practice today, when I see patients with elevated cardiovascular risk, metabolic syndrome, or signs of chronic inflammation, vitamin K2 status is one of the first things I consider. The near-universal deficiency (estimated at 97% of the population) means that for most people, supplementation is not just reasonable — it may be essential for long-term vascular health.
I also personally take vitamin K2 as part of my own nutrition protocol. As a perimenopausal woman with a family history of cardiovascular risk factors, the 2025 data on blood pressure reduction and arterial stiffness in women with my profile is particularly compelling to me — not just as a clinician, but as a patient.
One pattern I see consistently: patients who address vitamin K2 deficiency as part of a broader root-cause functional nutrition approach tend to see improvements across multiple cardiovascular markers simultaneously. Nutrients rarely work in isolation — and K2 is especially synergistic with vitamin D3, magnesium, and omega-3 fatty acids.
I also recommend reading about the broader benefits of vitamin K2 supplements and how to choose the best form, as well as the important role of K2 in children’s bone health.
CAC scoring by CT scan is considered one of the strongest independent predictors of cardiovascular events available in clinical practice today. If you or someone you love has received a CAC score above zero — especially alongside other metabolic risk factors — it is worth discussing vitamin K2 status with your healthcare provider.
What Drives a High CAC Score? Key Risk Factors to Know
A CAC score does not emerge from nowhere. Understanding what drives coronary artery calcification in the first place is essential — both for interpreting your own score and for taking meaningful action. Here is what the research shows about the most significant contributors, and why I address each of these systematically with clients at elevated cardiovascular risk.
Obesity is one of the most consistently documented drivers of coronary artery calcification. Research from the Framingham Heart Study found that obesity defined by BMI was strongly associated with high CAC scores, even after adjusting for other cardiovascular risk factors. Importantly, this association held even in people without diabetes. More striking, a study in obese youth found that 50% of obese adolescents already had detectable coronary artery calcification — and adiposity was the primary determinant. Excess abdominal fat in particular promotes chronic low-grade inflammation that accelerates arterial calcification over time. From a clinical standpoint, this is one of the strongest arguments I make for addressing body composition early and proactively — not waiting for a cardiac event to act.
A systematic review and meta-analysis of nearly 13,000 patients found that diabetes was one of the most consistent and powerful predictors of both the presence and extent of coronary artery calcification across multiple studies. Both type 1 and type 2 diabetes accelerate calcification through multiple mechanisms: advanced glycation end-products (AGEs) that stiffen arterial walls, elevated oxidative stress, and impaired vitamin K-dependent protein activation. This last point is particularly relevant — high blood sugar is known to impair the carboxylation of MGP, which means diabetic patients may need even more attention to vitamin K2 status to keep their calcification inhibitor functioning optimally. Prediabetes and elevated fasting glucose also carry significant risk before a formal diabetes diagnosis is ever made.
High sugar intake — particularly from sugar-sweetened beverages — has a measurable relationship with coronary artery calcification. A large cross-sectional study of over 22,000 adults found that high sugar-sweetened carbonated beverage consumption was associated with a significantly higher prevalence and degree of CAC in people with no prior history of cardiovascular disease or diabetes. A 2024 longitudinal analysis from the CARDIA study also found that cumulative sugar-sweetened beverage intake across young adulthood was linked to CAC risk in midlife. The mechanisms are multi-pronged: high sugar drives insulin resistance, systemic inflammation, triglyceride elevation, and directly promotes AGE formation in vessel walls. In my practice, reducing added sugar — especially liquid sugar — is one of the first dietary interventions I address with any patient concerned about cardiovascular calcification.
As I described earlier in this post from my own clinical experience, kidney disease patients face an especially aggressive calcification burden. The kidneys play a central role in phosphate and calcium metabolism — when kidney function declines, the resulting mineral dysregulation accelerates vascular and soft-tissue calcification dramatically. CKD patients on dialysis have calcification rates far exceeding the general population, and research consistently shows near-universal vitamin K2 deficiency in this group. Even moderate CKD (Stages 3–5) significantly elevates CAC risk, as demonstrated in the trials reviewed above. Addressing vitamin K2 deficiency in kidney disease patients is one of the most evidence-supported nutritional interventions available — which is precisely why multiple clinical trials have focused specifically on this population.
This one surprises many people, including some clinicians. A large subgroup analysis of the Multi-Ethnic Study of Atherosclerosis (MESA) found that statin use was associated with increasing CAC scores — more than any other established cardiovascular risk factor in the multivariate model, even in low-risk patients with a baseline CAC of zero. A separate retrospective study found that long-term statin therapy was associated with severe coronary artery calcification. And a JACC analysis confirmed that increasing duration of statin therapy was associated with higher CAC scores.
The important nuance here — and I emphasize this carefully with patients — is that this does not mean statins are harmful overall. The current evidence suggests that statins may stabilize existing plaques by promoting their calcification (turning soft, rupture-prone plaques into denser, more stable ones), which is actually protective against acute cardiac events even as the CAC score rises. A 2025 review in the literature describes this as the “coronary calcium paradox.” What this does mean practically is that a rising CAC score in a statin user should not be interpreted the same way as in a statin-naive person — and that statin use should always be noted when a CAC score is being evaluated. It is also worth noting that statins deplete CoQ10, which has its own implications for cardiovascular and mitochondrial health.
Best Food Sources of Vitamin K2
Getting enough vitamin K2 from food alone is genuinely difficult for most people eating a typical Western diet. Here are the highest food sources — and why supplementation is often necessary to reach therapeutic levels.
Notice that natto is in a league of its own — but most Americans and Europeans have never tried it and find the taste very challenging. This is one of the primary reasons an estimated 97% of the population is K2 deficient, and why supplementation with a clinically validated form like MenaQ7 makes practical sense.
Vitamin K2 Dosing: What the Research Supports
- Healthy adults for cardiovascular protection: 180 mcg/day of MK-7 (MenaQ7) — the dose from the 3-year landmark postmenopausal women trial
- Hemodialysis patients: 135–360 mcg/day, under medical supervision
- CKD patients (Stage 3–5): 90 mcg/day combined with vitamin D3, under physician guidance
- High-risk cardiac populations: Up to 720 mcg/day as used in the AVADEC trial — physician supervision required
For more on choosing the right supplement form, see my detailed guide on the best vitamin K2 supplement brands and benefits. You may also want to explore the connection between K2 and colon health in my post on K2 vitamins for colon benefits.
My bestselling book Cortisol Fix — #1 in Endocrinology on Amazon — explores how stress hormones, nutrition, and cardiovascular health intersect. It is the root-cause guide I wish every patient received years earlier.
Get Cortisol Fix on Amazon →Vitamin K2 and Atherosclerosis: Key Takeaways
- Arterial calcification is the primary driver of atherosclerosis and one of the leading causes of cardiovascular death globally
- Vitamin K2 (especially as MK-7) activates Matrix Gla Protein — the body’s natural calcification blocker
- An estimated 97% of people are vitamin K2 deficient
- Five foundational MenaQ7 clinical trials show improved arterial health in both healthy and high-risk populations
- The 2025 VitaK-CAC trial showed MK-7 arrested coronary artery calcification progression by 22%
- 2025 data confirmed K2 supplementation reduces blood pressure and vascular stiffness in postmenopausal women
- 180 mcg/day of MK-7 is the best-supported dose for healthy adults
- Vitamin K2 works synergistically with vitamin D3
If you are interested in learning more about related topics in functional cardiovascular nutrition, explore my posts on preventing premature aging with diet and the gut-heart connection through superfoods for gut health.
Frequently Asked Questions About Vitamin K2 and Atherosclerosis
Can vitamin K2 reverse arterial calcification?
Clinical evidence suggests vitamin K2 (as MK-7) may help slow or partially reverse arterial calcification by activating Matrix Gla Protein (MGP), the body’s primary calcification inhibitor. A landmark 3-year trial in postmenopausal women found 180 mcg/day of MK-7 reduced arterial stiffness. The 2025 VitaK-CAC trial showed MK-7 arrested coronary artery calcification progression by 22% in patients with mild-to-moderate coronary artery disease. The strongest reversal effects have been seen in individuals who were most deficient at baseline.
What is the best form of vitamin K2 for heart health?
Menaquinone-7 (MK-7) is the most extensively studied form of vitamin K2 for cardiovascular outcomes. It has a significantly longer half-life (~3 days) compared to MK-4, allowing it to stay active longer in the body and reach peripheral tissues including artery walls. MenaQ7 is a patented, clinically validated MK-7 form used across more cardiovascular trials than any other form of K2.
How much vitamin K2 should I take to prevent atherosclerosis?
For healthy adults seeking cardiovascular protection, 180 mcg per day of MK-7 is the dose supported by the strongest clinical evidence. Higher doses (360 mcg+) have been used in clinical populations such as kidney disease patients, always under medical supervision. Always consult a healthcare provider before starting supplementation, especially if you take blood thinners or have kidney disease.
What foods are highest in vitamin K2?
Natto (fermented soybeans) is by far the richest food source of vitamin K2 MK-7, providing well over 1,000 mcg per serving. Other sources include hard aged cheeses like Gouda and Edam, pastured egg yolks, grass-fed butter, chicken liver, and grass-fed beef. Most modern Western diets provide far less than the amounts associated with cardiovascular benefit in clinical trials, which is why supplementation is often warranted.
Does vitamin K2 interact with blood thinners?
Yes. Vitamin K2 can interfere with warfarin (Coumadin) and similar anticoagulant medications because vitamin K plays a role in coagulation factor activation. If you are taking blood thinners, consult your physician before supplementing with vitamin K2. In most cardiovascular K2 trials, patients on vitamin K antagonists were excluded for this reason.
What is MGP and why does it matter for heart health?
Matrix Gla Protein (MGP) is the body’s most potent natural inhibitor of soft tissue and arterial calcification. It is produced locally in artery walls, but must be activated (carboxylated) by vitamin K2 to function. When vitamin K2 status is low, MGP remains inactive and calcium is free to deposit in artery walls — accelerating atherosclerosis. Supplementing with MK-7 increases active MGP levels, helping protect arteries from calcification. Measuring dp-ucMGP (inactive MGP) in blood is one of the most sensitive markers of vitamin K2 deficiency available.
Does vitamin K2 work better with vitamin D?
Emerging evidence suggests a synergistic relationship between vitamins K2 and D3. The AVADEC study and the stage 3–5 CKD trial both used K2+D3 combinations and found cardiovascular benefits. Vitamin D may increase the production of vitamin K-dependent proteins including MGP, while K2 ensures those proteins are activated. Many practitioners and researchers — myself included — recommend combining K2 with D3 for optimal cardiovascular and bone health outcomes.
Should I take vitamin K2 if I have a high coronary artery calcium (CAC) score?
A CAC score above zero is an early warning sign that calcification is already present in the coronary arteries — and any score paired with other metabolic risk factors warrants proactive attention. The 2025 VitaK-CAC trial demonstrated that two years of MK-7 supplementation can meaningfully slow CAC progression by 22%. In clinical practice, I consistently recommend discussing vitamin K2 status with a healthcare provider for anyone with a detected CAC score, given K2’s unique and documented role in activating MGP — the body’s primary calcification inhibitor. Always work with your physician before starting supplementation, particularly if you take blood thinners.
Heidi Moretti is a registered dietitian with 25+ years of clinical experience and a Certified LEAP Therapist specializing in functional nutrition, gut health, and cardiovascular wellness. She is the founder of The Healthy RD and co-founder of Align Wellness in Missoula, Montana. Her bestselling books include Cortisol Fix, Period Fix, Gut Fix, and The Whole Body Guide to Gut Health.
Many thanks for all this great detailed information info on K2……..I have been diagnosed with osteoporosis and have been taking a vitamin K2 mk7 supplement from fermented chickpeas …..and have great faith ………however, as self treating I am only taking a 100mcg tablet a day and wondering if dose is too low…….I am of course eating eggs butter cheeses but aware these contain only small amounts of K2………….Should I augment my K2 …….from what I understand you can’t overdose…………any advise greatly appreciated…….Kind regards, Hilary
As long as you are not on warfarin, taking 180 micrograms long-term appears safe according to research. Good luck and hope that helps! Heidi
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I was not able to download my Free Guide to Healthy Supplements
My apologies! Here is a link to the free guide: https://docs.google.com/document/d/10vTyEg1Tt51QpXKmbFc386jd2bdu7IeTF2DpVgjyL50/edit?usp=sharing