The Heart Benefits of Vitamin K in Leafy Greens : A Simple Guide

Vitamin K is a fat-soluble nutrient that helps the body perform essential tasks, such as blood clotting, bone health and maintaining healthy blood vessels. It also helps prevent vascular calcification, a process where calcium collects in artery walls and reduces flexibility.

There are two main forms:

Vitamin K1 (phylloquinone) — found mostly in leafy greens high in Vitamin K

Vitamin K2 (menaquinones) — found in fermented foods and some animal products

Both support the heart, but Vitamin K1 from green leafy vegetables is the easiest and most common way to get the amount of vitamin needed for heart protection.

Vitamin K plays an important role in keeping your heart and blood vessels healthy. Here’s how:

Vitamin K activates a protein called MGP, which helps stop calcium from hardening your arteries. This keeps blood vessels flexible and promotes smooth blood flow, reducing strain on the heart.

Vitamin K helps your body form clots when needed while keeping clotting under control. This is especially important for:

• Adults with cardiovascular disease
• People with diabetes
• Anyone taking blood thinners like warfarin

If you take blood-thinning medication keep your vitamin K intake consistent.

Research shows higher vitamin K is linked to:

• Less arterial stiffness
• Lower risk of atherosclerosis
• Better overall heart and vessel health over time

“While vitamin K isn’t a replacement for medications, it has a valuable potential role in a heart-healthy eating pattern,” Dr. Uddin says.

Leafy greens may do more than protect your arteries. They could help maintain the heart’s structure. The 2017 study in The Journal of Nutrition found that teens with the lowest vitamin K intake had larger left ventricles, the heart’s main pumping chamber. An enlarged left ventricle is linked to a higher risk of future cardiovascular disease.

Teens who ate more vitamin K-rich greens, such as spinach and kale, had healthier heart measurements. These findings suggest that leafy greens may support heart health early in life and play a role in long-term protection.

Additional research from Edith Cowan University and the University of Western Australia supports this link, associating higher vitamin K intake with reduced risk of heart attacks, strokes and hospitalizations for vascular disease.

Leafy greens are packed with heart-healthy nutrients. They provide vitamin K1 along with fiber, potassium, magnesium and antioxidants. These nutrients support blood pressure, cholesterol levels and overall heart health.

Common leafy greens high in vitamin K include:

• Kale
• Spinach
• Broccoli
• Collard greens
• Cabbage
• Romaine lettuce

Even small servings add meaningful benefits.

Most adults need only a small amount of vitamin K each day, which doctors say is best obtained from food. A single serving of dark-green leafy vegetables can meet most or all daily needs, while also providing fiber and other nutrients.

Physicians recommend eating dark-green vegetables regularly as part of a balanced, varied diet rather than relying on supplements.

Here are easy ways to increase your intake:

• Add spinach to eggs
• Blend kale or spinach into smoothies
• Toss broccoli into stir-fries
• Make salads with mixed greens
• Use greens as a base for bowls or wraps

Building heart-healthy habits starts with small, consistent choices. Adding leafy greens rich in Vitamin K to your meals is one of the simplest — and most effective — steps you can take.

“These vegetables provide essential nutrients and long-term benefits backed by research, helping keep your heart strong, flexible and healthy for years to come,” Dr. Uddin says.