Are all green vegetables high in vitamin K?

November 16, 2025 •

3 min read

According to the USDA, dark leafy greens like kale and spinach are among the richest sources of vitamin K, containing well over 100% of the daily value per serving. However, the idea that are all green vegetables high in vitamin K is a common misconception, as some green varieties contain very little of this important nutrient.

Quick Summary

The vitamin K content varies significantly among different green vegetables. While dark leafy greens are a primary source, lighter-colored green vegetables like iceberg lettuce and some root vegetables have low amounts. Understanding these differences is crucial for dietary planning and managing specific health conditions.

Key Points

Not all green vegetables are high in vitamin K: The concentration of this vitamin varies widely depending on the type of vegetable.
Dark, leafy greens are the best source: Vegetables like kale, spinach, and collard greens are exceptionally high in vitamin K.
Lighter greens contain very little vitamin K: Examples include iceberg lettuce, which offers a minimal amount compared to darker varieties.
Cooking affects concentration: Boiling or cooking leafy greens can increase their vitamin K content relative to their weight.
Absorption is enhanced by fat: Since vitamin K is fat-soluble, eating greens with a source of fat improves absorption.
Crucial for specific medical conditions: Those taking blood thinners must be aware of their vitamin K intake to avoid interfering with medication.

The Truth Behind Vitamin K and Green Vegetables

While it's a common belief that all green vegetables are a high source of vitamin K, this is not entirely accurate. The term "green vegetable" encompasses a wide range of produce, and their vitamin K content can vary dramatically. Phylloquinone (Vitamin K1), the type predominantly found in plants, is concentrated most heavily in the chloroplasts, the green parts of the plant responsible for photosynthesis. This is why darker, leafier greens are nutritional powerhouses for this particular vitamin, while lighter or less leafy varieties offer much smaller quantities.

What is Vitamin K and Why is it Important?

Vitamin K is a fat-soluble vitamin essential for several bodily functions. Its most well-known role is in blood clotting, a process called coagulation. The "K" in its name actually comes from the German word Koagulation. Beyond coagulation, vitamin K is also critical for maintaining bone health and helping to regulate calcium levels in the body. A balanced diet should include sufficient vitamin K, especially for those on blood-thinning medications like warfarin, who need to maintain a consistent intake.

High-Vitamin K Green Vegetables

Dark, leafy greens are the undisputed champions when it comes to vitamin K content. Some top contenders include:

Kale: Often hailed as a superfood, a single cup of cooked kale can provide several times your daily needs.
Spinach: Cooked spinach is incredibly potent, but even raw spinach is an excellent source of vitamin K.
Collard Greens: These hearty greens are another rich source, particularly when cooked.
Swiss Chard: With both edible leaves and stalks, this vegetable is loaded with vitamin K.
Broccoli and Brussels Sprouts: These cruciferous vegetables are also great sources, offering significant amounts of vitamin K in a single serving.

Green Vegetables with Lower Vitamin K Content

It's important to remember that not all green vegetables are created equal. Several common green varieties contain surprisingly low amounts of vitamin K, which is vital information for those needing to monitor their intake carefully.

Iceberg Lettuce: Unlike its dark green cousins, iceberg lettuce is very low in vitamin K.
Green Beans: While still green, these provide a much smaller amount of vitamin K compared to leafy greens.
Celery: This crunchy vegetable contains modest levels of vitamin K.
Green Bell Peppers: Though green in color, bell peppers are not a significant source of vitamin K.
Zucchini: This popular summer squash is a low-vitamin K option.

Comparison of Vitamin K Content in Green Vegetables


Vegetable	Type	Relative Vitamin K Content	Daily Value per 1 Cup Cooked (approx.)	Notes
Spinach	Dark Leafy Green	Very High	888 mcg (740% DV)	Vitamin K is concentrated when cooked.
Kale	Dark Leafy Green	Very High	544 mcg (453% DV)	A nutritional powerhouse.
Broccoli	Cruciferous	High	220 mcg (183% DV)	A reliable source for vitamin K.
Green Beans	Legume	Low	60 mcg (50% DV)	Contains significantly less than leafy greens.
Iceberg Lettuce	Light-Colored Leafy Green	Very Low	17.4 mcg (14% DV)	Offers minimal vitamin K.
Zucchini	Squash	Very Low	8 mcg (6% DV)	Not a primary source of vitamin K.

Factors Influencing Vitamin K in Vegetables

The vitamin K content in vegetables is not static. Several factors can influence the final amount found in your food. For instance, cooking can concentrate the vitamin K content in leafy greens by reducing their water volume. Additionally, because vitamin K is fat-soluble, consuming greens with a source of healthy fat, like olive oil in a salad dressing, can enhance its absorption. The growing conditions and specific variety of the vegetable can also cause variations in nutrient levels.

Conclusion

In summary, the notion that all green vegetables are high in vitamin K is a simplification. While dark, leafy greens and certain cruciferous vegetables are excellent sources, many lighter-colored or less dense green vegetables provide only modest or negligible amounts. For individuals monitoring their vitamin K intake, such as those on anticoagulant therapy, it is crucial to understand these distinctions. For most people, consuming a wide variety of vegetables ensures a balanced nutrient intake, but knowing which ones are highest in vitamin K helps with targeted dietary planning.

For more detailed nutritional information, visit the USDA FoodData Central database.

Frequently Asked Questions

Yes, there is a major difference. Darker lettuces like romaine and green leaf contain higher levels of vitamin K, while iceberg lettuce contains a very low amount.

Cooking, particularly boiling, reduces the water content of leafy greens, which concentrates the vitamin K. This means cooked spinach, for example, has more vitamin K per cup than raw spinach.

The main reason is that the green pigment, chlorophyll, which drives photosynthesis, is where vitamin K (phylloquinone) is stored. Vegetables that are less leafy or lighter in color have less chlorophyll and therefore less vitamin K.

Vitamin K is essential for the body's blood clotting process (coagulation). It also plays a vital role in bone health and calcium metabolism.

No, green vegetables are the primary source of Vitamin K1 (phylloquinone). Vitamin K2 (menaquinone) is found mainly in animal products and fermented foods.

For most healthy people, there is no risk of toxicity from consuming too much vitamin K from food. However, individuals on blood-thinning medications need to maintain a consistent intake to avoid impacting their medication's effectiveness.

While green leafy vegetables are the richest source, some non-green foods do contain vitamin K. For example, certain fruits like kiwis and some fermented foods like natto also contain significant amounts.