How much vitamin K is in butter? Understanding its content and sources

November 14, 2025 •

3 min read

According to nutrition data, a single tablespoon of butter contains approximately 0.99 micrograms (mcg) of vitamin K, specifically the K1 variant. However, the total vitamin K content in butter can vary and is primarily composed of the K2 type, which is also produced by gut bacteria and found in other animal and fermented foods.

Quick Summary

Butter contains a small amount of vitamin K, mainly the K2 variant. The exact quantity depends on factors like the cow's diet, with grass-fed butter generally having more. While not a primary source, butter is one of several ways to obtain this fat-soluble vitamin. Other food sources, particularly leafy greens for K1 and fermented products for K2, offer significantly higher amounts.

Key Points

Moderate Content: Butter contains a small, but not significant, amount of vitamin K, mostly in the form of K2.
Grass-Fed Difference: Grass-fed butter typically contains higher levels of vitamin K2 compared to butter from grain-fed cows.
K2 is the Key Type: The vitamin K in butter is predominantly K2 (menaquinone), which plays a role in bone and cardiovascular health.
Better Sources Exist: Leafy green vegetables are far superior sources of vitamin K1, while natto and certain cheeses are much richer in K2.
Moderation is Recommended: Due to its high fat and calorie content, butter should be consumed in moderation, and not relied upon as a primary source of vitamin K.
Absorption Aid: As a fat-soluble vitamin, adding a small amount of butter or other fat can increase the absorption of vitamin K from plant sources.

Is butter a significant source of vitamin K?

While butter does contain vitamin K, it is not considered a primary or significant source compared to other foods like leafy green vegetables or fermented products. The vitamin K found in butter is primarily vitamin K2 (menaquinone), with smaller amounts of vitamin K1 (phylloquinone). The exact amount can be influenced by the diet of the dairy cow, with grass-fed butter often containing higher levels of K2.

The types of vitamin K in butter

It's important to understand the two main types of vitamin K:

Vitamin K1 (Phylloquinone): This is the predominant form of vitamin K in the human diet and is found in high concentrations in green leafy vegetables. Our bodies absorb K1 less efficiently than K2.
Vitamin K2 (Menaquinone): Found in animal products and fermented foods, K2 is absorbed much more readily by the body and is believed to have different health benefits, particularly concerning bone and heart health. There are several subtypes of K2 (MK-4 to MK-13), with butter being a source of MK-4.

The vitamin K in butter comes from the cow's diet. When cows eat fresh grass, the K1 from the plants is converted into K2 (MK-4) in their bodies, which is then stored in their fat and ends up in their milk and, subsequently, butter.

Nutritional comparison: Butter vs. other vitamin K sources

As a fat-soluble vitamin, combining vitamin K-rich vegetables with a fat source like butter can help increase its absorption. The following table provides a comparison of the vitamin K content in butter against other common food sources, highlighting why butter is a modest contributor.


Food Source	Serving Size	Vitamin K Content (approx.)	Primary Type	Notes
Kale, cooked	1 cup	418.5 mcg	K1	Excellent source
Natto (fermented soybeans)	100 g	939 mcg	K2	Exceptional source
Butter (grass-fed)	1 tablespoon (14 g)	2.1 mcg	K2	Moderate source; varies with diet
Spinach, cooked	1 cup	540.7 mcg	K1	Excellent source
Hard cheese	100 g	76 mcg	K2	Good source
Beef liver	100 g	106 mcg	K2	Very good source

How to get more vitamin K in your diet

Since butter provides a relatively small amount of vitamin K, diversifying your dietary sources is the most effective approach. Here are some options:

For Vitamin K1: Incorporate more dark, leafy greens into your meals. Consider adding spinach, kale, collard greens, or Brussels sprouts to salads, smoothies, or cooked dishes.
For Vitamin K2: While butter and cheese contain some K2, consider other options. Fermented foods like natto are exceptionally high in K2, while goose and beef liver are also excellent animal-based sources.
Enhance Absorption: When consuming K1-rich vegetables, include a source of healthy fat, such as olive oil or a small amount of butter, to aid absorption.
Moderation is Key: While grass-fed butter offers nutritional benefits beyond K2, it is also high in saturated fat and calories. It should be consumed in moderation as part of a balanced diet.

The health implications of vitamin K from butter

Vitamin K, in both its forms, is essential for vital bodily functions, including blood clotting and bone health. Vitamin K2, in particular, helps regulate calcium, preventing its buildup in arteries and redirecting it to the bones where it is needed. Therefore, including sources of K2 in your diet is important for cardiovascular and skeletal health. Although butter is not the most potent source, it is a convenient and palatable one, especially grass-fed varieties. The total contribution to your daily intake will depend heavily on your overall dietary patterns. For those looking to increase their vitamin K intake, relying on a diverse range of foods is more effective than focusing solely on butter.

Conclusion

In summary, while butter does contain vitamin K, primarily K2, the amount is modest when compared to other sources such as leafy greens and fermented foods. Grass-fed butter offers a higher concentration of K2 than conventional butter, but even then, it is not a primary dietary source. For optimal intake of both K1 and K2, a balanced diet rich in leafy vegetables, fermented foods, and other animal products is recommended. Butter can be a part of this dietary pattern, but a variety of foods should be prioritized to meet your daily vitamin K needs.

Learn more about vitamin K's functions and sources on the Linus Pauling Institute website.

Frequently Asked Questions

Yes, butter contains a small amount of vitamin K, specifically the K2 variant. The exact quantity depends on the cow's diet and how the butter is produced.

No, butter is not considered a particularly good or significant source of vitamin K. While it contains some, other foods like leafy greens and fermented products offer much higher amounts.

Yes, grass-fed butter generally contains more vitamin K2 than regular butter. This is because cows fed a diet of fresh grass ingest more vitamin K1, which their bodies convert into K2.

Vitamin K1 (phylloquinone) is found in plants like leafy greens, while vitamin K2 (menaquinone) is found in animal products and fermented foods. K2 is absorbed more efficiently by the body and may offer unique health benefits.

Since vitamin K is fat-soluble, consuming it with a source of fat can enhance its absorption. You can maximize absorption by adding a little butter or oil to your leafy green vegetables.

Excellent sources of vitamin K include natto (fermented soybeans), leafy green vegetables like kale and spinach, beef liver, and various types of cheese.

No, relying on butter for your vitamin K intake is not recommended. It is high in calories and saturated fat, and far better sources of vitamin K are available through a more varied diet.