Where Do We Get Our Vitamin K From?

January 13, 2026 •

3 min read

According to the National Institutes of Health, most people in the United States get enough vitamin K from the foods they eat, but understanding the specific sources is key. This essential nutrient, critical for blood clotting and bone health, is actually a group of compounds, so the answer to 'Where do we get our vitamin K from?' involves looking at a variety of foods.

Quick Summary

This article details the primary sources of vitamin K, differentiating between K1 from plants and K2 from fermented and animal foods. It highlights foods like kale, natto, and cheese, emphasizing the role of diet and gut bacteria in obtaining this vital nutrient.

Key Points

Two Primary Forms: Vitamin K1 (phylloquinone) is found in plants, while Vitamin K2 (menaquinone) comes from fermented foods and animal products.
Leafy Greens are Key: Excellent sources of Vitamin K1 include kale, spinach, collard greens, broccoli, and Brussels sprouts.
K2 from Unique Sources: To get Vitamin K2, incorporate fermented foods like natto and cheeses, along with animal products such as egg yolks and organ meats.
Fat Enhances Absorption: Since vitamin K is fat-soluble, consuming it alongside healthy fats like olive oil or avocado improves your body's ability to absorb it.
Bacteria Play a Role: Your gut bacteria produce a small amount of Vitamin K2, but dietary intake is necessary for most of your needs.
Diverse Diet is Best: The best way to get all the vitamin K you need is through a balanced diet that includes a variety of both plant-based and fermented/animal sources.

Understanding the Two Main Forms of Vitamin K

Vitamin K is not a single compound but a group of fat-soluble vitamins. The two most important forms for human nutrition are Vitamin K1 (phylloquinone) and Vitamin K2 (menaquinone). Each is found in different types of food, making dietary diversity crucial for adequate intake.

Vitamin K1: The Plant-Based Powerhouse

Vitamin K1, or phylloquinone, is the most abundant dietary form and is produced by plants. Your body absorbs this vitamin, and bacteria in your large intestine can convert some of it into a storage form, K2. The best sources are generally green, leafy vegetables.

Top sources of Vitamin K1

Kale: One of the most vitamin K-dense foods available.
Spinach: Both raw and cooked spinach contain significant amounts.
Collard greens: Another cruciferous vegetable packed with K1.
Broccoli: A great source that can be easily added to many meals.
Brussels sprouts: These small, green vegetables are also rich in K1.
Vegetable oils: Certain oils, particularly soybean and canola, contain notable amounts of Vitamin K1.

Vitamin K2: From Fermented Foods and Animal Products

Vitamin K2, or menaquinone, is found predominantly in fermented foods and certain animal products. It is also produced by the bacteria in your gut. Unlike K1, K2 has several subtypes, and its content can vary significantly based on the production process.

Key sources of Vitamin K2

Natto: This traditional Japanese dish of fermented soybeans is the richest known source of Vitamin K2.
Hard and soft cheeses: Gouda, Brie, and other fermented cheeses are reliable sources of K2.
Egg yolks: The yolk of an egg contains a modest amount of K2.
Chicken liver and other organ meats: These are strong sources, particularly of the MK-4 subtype of K2.
Sauerkraut: Fermented cabbage contains beneficial gut bacteria that produce K2.

Bioavailability and the Role of Fat

As a fat-soluble vitamin, both K1 and K2 are absorbed more effectively when consumed with dietary fat. For example, adding olive oil to a kale salad or enjoying cheese with your vegetables can significantly improve absorption.

Comparison of Vitamin K1 and Vitamin K2 Sources


Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Primary Sources	Green leafy vegetables, vegetable oils, some fruits	Fermented foods, animal products like cheese, egg yolks, liver
Synthesized by	Plants	Gut bacteria in the large intestine
Dietary Abundance	Most common dietary form	Less common in modern Western diets
Absorption	Better absorption when eaten with fat	Better absorption and longer half-life than K1
Primary Function	Critical for blood clotting	Important for bone health and preventing arterial calcification
Example Foods	Kale, spinach, broccoli, soybean oil	Natto, cheese, egg yolks, chicken

Additional Considerations for Vitamin K Intake

While the primary source for most people is diet, it is important to remember other factors. Some of our gut bacteria produce a limited amount of Vitamin K2, although this is generally not enough to meet daily requirements. For individuals with malabsorption disorders or those taking certain medications, supplements may be recommended by a healthcare provider. Additionally, newborns are given a single shot of Vitamin K at birth to prevent a rare bleeding disorder.

Conclusion

To ensure adequate vitamin K intake, it is vital to consume a diverse diet rich in both Vitamin K1 and K2 sources. Regularly including dark leafy greens like spinach and kale alongside fermented foods such as cheese or natto provides a comprehensive approach. Prioritizing whole food sources and pairing them with healthy fats will optimize your body's ability to absorb this crucial nutrient, supporting everything from proper blood clotting to maintaining strong, healthy bones.

Frequently Asked Questions

The richest food sources of Vitamin K1 are dark green leafy vegetables, including kale, spinach, collard greens, and broccoli.

Vitamin K2 is primarily found in fermented foods, such as natto (fermented soybeans) and cheese, as well as in some animal products like egg yolks and chicken liver.

Yes, bacteria in the large intestine can produce some Vitamin K2. However, this amount is often not enough to satisfy the body's total requirement, so obtaining it from diet is still necessary.

Vitamin K is a fat-soluble vitamin, meaning it dissolves in fat. Consuming it with dietary fat, like vegetable oil or avocado, significantly improves its absorption in the body.

There are synthetic forms of vitamin K, such as phytonadione (a synthetic K1) used in supplements and menadione (K3), though K3 is no longer used in supplements due to safety concerns.

Vegetarians can get plenty of Vitamin K1 from plant sources. However, they may need to be more mindful of obtaining Vitamin K2, which is less common in their diet but can be found in fermented foods like natto or sauerkraut.

For most healthy adults, a balanced diet provides sufficient vitamin K. Supplements may be recommended by a healthcare provider for individuals with certain medical conditions, malabsorption issues, or newborns.