Study: Vitamin K May Help Keep Your Heart Healthy

While certain vitamins tend to get the spotlight, particularly vitamins C and D, lesser-known ones like vitamin K are equally important for our health. Now, new research finds that vitamin K may be key in keeping your heart healthy.

Researchers found that people who had a diet rich in vitamin K were at a lower risk of developing atherosclerosis-related cardiovascular disease (ASCVD). The August study was published in the Journal of the Medical Heart Association.

Melissa Azzaro, RDN, LD, a New Hampshire-based registered dietitian and author of "A Balanced Approach to PCOS," shares that these results are not surprising to her, as “vitamin K2 protects against calcium being released from bone into the bloodstream—where it can deposit in soft tissues like the blood vessels, which can be problematic.”

What Is Vitamin K?

Vitamin K occurs in 2 forms: vitamin K1 and vitamin K2. Vitamin K1 is primarily found in green leafy foods like spinach and kale, while vitamin K2 is found in many fermented foods, such as natto and certain cheeses. Both act differently in the body, but both are important.

“Vitamin K has several roles in the body from blood clotting to bone health,” Michelle Routhenstein, MS, RD, CDE, CDN, a New York-based preventive cardiology dietitian and owner of Entirely Nourished, LLC., tells Verywell. “For instance, Vitamin K2 is needed to assist calcium into the bone versus the soft tissue (the heart muscle). Vitamin K consumption also protects against cardiomegaly, the enlargement of the left ventricle, the major pumping chamber of the heart.” 

Including More Vitamin K in Your Diet May Improve Heart Health

Tried-and-true ways for reducing the risk of ASCVD include eating more produce and eating less sodium. Lesser known is the role vitamin K plays in the prevention of this disease. 

For the study, researchers evaluated whether dietary intake of vitamins K1 and K2 was linked to ASCVD-related hospitalizations—ischemic heart disease, ischemic stroke, and peripheral artery disease—in Danish individuals.

Over 53,000 participants completed a food‐frequency questionnaire and were tracked for hospital admissions.

The main dietary sources of vitamin K1 eaten by participants were margarine, lettuce, broccoli, whole‐meal bread, and spinach. Eggs, butter, and hard cheeses were the main dietary sources of vitamin K2.

Compared with people with the lowest amount of vitamin K1, participants with the highest intake were at a 21% lower risk of an ASCVD‐related hospitalization. For participants with the highest intake of vitamin K2, their chance of hospitalization was 14% lower than participants on the lower end.

Specifically, researchers found, when compared with those who ate the lowest amounts of vitamin K, those who took in the most experienced:

• 14% lower risk of ischemic heart disease-related hospitalization
• 17% lower risk of stroke-related hospitalization
• 34% reduced risk of peripheral artery disease-related hospitalization. 

Still, in some cases, eating high amounts of this nutrient did not offer additional heart-health benefits.

Since many foods that contain vitamin K2 are rich in saturated fat (butter, cheese, eggs), eating too many of these foods may result in a person overconsuming this unhealthy fat—counteracting the potential heart-health benefits.  

How Does Vitamin K Play a Role in Heart Health?

There are several ways vitamin K may play a role in ASCVD risk. 

For one, vitamin K deficiency has previously been linked to an increased risk of more calcium build-up in the arteries, which can lead to cardiovascular disease.

Getting enough vitamin K1 may also help manage systemic inflammation. Inflammation can lead to ASCVD. And the vitamin can also help regulate insulin resistance, which factors into the development of heart disease.

Eating More Foods With Vitamin K

Eating more vegetables and fermented foods will give your body a boost of vitamin K along with other nutrients.

Some ways to include more vitamin K in your diet include:

• Incorporating green leafy vegetables in your diet like kale, brussels sprouts, and spinach
• Choose romaine lettuce instead of iceberg in salads
• Include organic meat in your diet
• Choose eggs from pasture-raised chickens
• If including butter in your diet, choose butter made from grass-fed cows.

While vitamin K supplements are available, more data is needed before definitive recommendations can be made about whether taking them offers benefits for heart health in the same way that eating certain foods does. 

And if you are taking a blood-thinning medication (like Warfarin), it is important to talk to your doctor before you start increasing your green leafy veggie intake, as making any large changes may negatively interact with your medications.