What Plant Has the Most Vitamin K?

November 14, 2025 •

3 min read

Over 50% of the daily value for vitamin K can be found in a single cup of cooked spinach. While many plants offer this essential nutrient, particularly leafy greens, a fermented food derived from a plant source stands out as the ultimate powerhouse for vitamin K content.

Quick Summary

This guide reveals the top vitamin K plant sources, differentiating between K1 and K2. It details why fermented natto, from soybeans, outshines leafy greens in total vitamin K content. Readers can learn about the different forms of the vitamin, their unique benefits, and how to incorporate high-K foods into their diet.

Key Points

Natto is the most vitamin K-rich plant food: A small portion of fermented soybeans (natto) provides the highest concentration of total vitamin K, particularly the K2 form.
Leafy greens are excellent sources of Vitamin K1: Cooked collard greens and turnip greens are among the most potent whole-food plant sources of vitamin K1.
Vitamin K is vital for blood clotting and bone health: This fat-soluble vitamin is essential for synthesizing blood-clotting proteins and regulating calcium for strong bones.
K1 and K2 have different origins and functions: K1 comes from plants, while K2 is produced by bacteria during fermentation and found in animal products.
Pairing with fat enhances absorption: Because vitamin K is fat-soluble, consuming plant sources with healthy fats like olive oil or avocado can maximize absorption.
Symptoms of deficiency relate to bleeding: A deficiency can lead to easy bruising, nosebleeds, and excessive bleeding, though severe cases are rare in healthy adults.

The Surprising Champion: Why Fermented Soybeans Are the Top Vitamin K Source

While many assume a common vegetable holds the crown, the highest concentration of total vitamin K comes not from a fresh plant, but from a fermented one. Natto, a traditional Japanese dish of fermented soybeans, is an exceptional source of vitamin K, specifically the K2 (menaquinone) form. The fermentation process, driven by the Bacillus subtilis bacteria, drastically increases its vitamin K2 content, with a 3-ounce serving providing a staggering amount—over 700% of the Daily Value.

The Importance of Vitamin K: More Than Just Blood Clotting

Vitamin K is a crucial fat-soluble vitamin necessary for several bodily functions. It's most famous for its role in synthesizing proteins required for proper blood clotting. Without enough vitamin K, minor injuries could lead to dangerous, uncontrolled bleeding. Beyond coagulation, the vitamin is also vital for bone health, helping to regulate calcium levels and preventing arterial calcification, which contributes to heart disease.

Two Types of Vitamin K: K1 and K2

There are two main types of natural vitamin K, and they are sourced differently with different functions.

Vitamin K1 (Phylloquinone): Primarily found in green leafy plants, such as spinach, kale, and collard greens. This form is essential for blood clotting and is what most people consume regularly.
Vitamin K2 (Menaquinone): Mainly produced by bacteria, both in the human gut and through food fermentation processes. It is most concentrated in fermented foods like natto and some animal products, and plays a more significant role in bone and cardiovascular health.

Top Vitamin K Plant-Based Sources (and the Fermented Champion)

While natto holds the title for the most concentrated source, many whole-food plants are excellent providers of vitamin K1. Incorporating a variety of these foods is the most effective way to ensure adequate intake.

Here are some of the best plant-based options:

Natto: As the undisputed champion, a small serving provides an enormous dose of vitamin K2, making it a unique and powerful source.
Cooked Collard Greens: A powerhouse among leafy greens, a single half-cup serving provides hundreds of micrograms of vitamin K1, far exceeding the daily requirement.
Cooked Turnip Greens: Similar to collard greens, these are another potent source, offering a high amount of vitamin K1 in a cooked half-cup portion.
Raw Spinach: Versatile and nutritious, a cup of raw spinach provides a strong dose of vitamin K1, perfect for salads and smoothies.
Raw Kale: A staple in many healthy diets, one cup of raw kale offers a significant amount of vitamin K1.
Broccoli: This popular cruciferous vegetable contains a good amount of vitamin K1 and is easily added to many meals.
Brussel Sprouts: These mini-cabbages are also rich in vitamin K1 and are a great addition to a varied diet.

A Comparison of Vitamin K Content


Food (Serving Size)	Vitamin K (mcg)	Form	Comment
Natto (3 oz)	850	K2 (MK-7)	The most concentrated source due to bacterial fermentation.
Collard Greens (½ cup, cooked)	530	K1	Excellent whole-food plant source.
Turnip Greens (½ cup, cooked)	426	K1	Another very high source of K1.
Raw Spinach (1 cup)	145	K1	Great for salads and general use.
Raw Kale (1 cup)	113	K1	Very accessible and popular leafy green.
Broccoli (½ cup, cooked)	110	K1	A common and reliable source.
Brussels Sprouts (1 cup, cooked)	156	K1	A nutritious and tasty option.

Maximize Your Vitamin K Absorption

Since vitamin K is a fat-soluble vitamin, consuming it with a source of healthy fat can improve absorption. For instance, drizzling a leafy green salad with olive oil or topping cooked greens with avocado can help your body better utilize the vitamin. Natto, as a fermented food, is also rich in beneficial bacteria that can aid in overall nutrient absorption.

Conclusion

While dark, leafy green vegetables like collard greens and spinach are superb sources of vitamin K1, the ultimate answer to "what plant has the most vitamin K" is natto, a product of fermented soybeans. The fermentation process supercharges the vitamin K2 content, making it an unrivaled source. By including a variety of these vitamin K-rich plants and fermented foods in your diet, and consuming them with healthy fats, you can support your body’s critical functions related to blood clotting, bone health, and heart health. Whether you choose a bowl of raw spinach or experiment with the unique flavor of natto, increasing your intake of this essential nutrient is a simple and effective way to boost your overall health.

Healthline.com Vitamin K Foods provides an extensive list of foods and their vitamin K content.

Frequently Asked Questions

Vitamin K1 (phylloquinone) is found in plants and is critical for blood clotting, while vitamin K2 (menaquinone) is produced by bacteria in fermented foods and in the gut, and is more important for bone and cardiovascular health.

Cooking methods like boiling can slightly reduce the vitamin K content, but cooked greens are often more concentrated due to water loss, meaning a smaller cooked portion can have more vitamin K than a larger raw portion.

Since vitamin K is a fat-soluble vitamin, consuming it with a source of healthy fat, such as olive oil in a salad dressing or avocado, can significantly increase its absorption.

Other plant-based sources include cruciferous vegetables like broccoli and Brussels sprouts, as well as certain fruits like kiwis and blueberries.

Natto is a potent source but has a distinct, strong flavor and sticky texture that not everyone finds palatable. It's a fermented soy product, so individuals with soy allergies should avoid it.

While gut bacteria do produce some vitamin K2, the amount is generally not enough to meet all of the body's requirements, making it important to get vitamin K through diet.

For most healthy individuals, a balanced diet rich in leafy greens and fermented foods provides sufficient vitamin K. Supplements are typically only necessary for those with absorption issues or specific medical conditions, and should be discussed with a doctor.