What animal foods are high in vitamin K?

While plant-based foods contain vitamin K1, most of the K2 variant—which plays a distinct role in bone and cardiovascular health—is found in animal-based products. This means that for individuals seeking to boost their intake of this specific nutrient, knowing what animal foods are high in vitamin K is crucial. These dietary sources include a variety of dairy products, organ meats, and poultry.

Quick Summary

Organ meats, cheese, eggs, and poultry are among the richest animal sources of vitamin K2, the form primarily found in animal products. The nutritional content is often influenced by the animal's diet, such as pasture-raised versus grain-fed livestock.

Key Points

• Rich K2 Sources: The most potent animal sources of vitamin K2 include goose liver pate, aged cheeses, and organ meats like beef liver.

• Eggs and Poultry: Eggs, particularly the yolks, and chicken meat are widely available and excellent sources of vitamin K2.

• Quality Over Quantity: The vitamin K2 content in animal foods is higher when sourced from pasture-raised or grass-fed animals.

• Fermented Products: Certain fermented animal products, like some types of cheese, are significant sources of K2 due to bacterial activity.

• Fat is Key: Vitamin K is fat-soluble, so consuming animal-based K2 sources with their natural fat aids in absorption.

• K1 vs. K2: While K1 comes from plants and helps with blood clotting, K2 from animal foods is more crucial for bone and cardiovascular health.

Understanding the Two Forms of Vitamin K

Vitamin K is a fat-soluble vitamin essential for blood clotting, bone health, and cardiovascular wellness. It primarily exists in two forms: K1 (phylloquinone) and K2 (menaquinones). While K1 is abundant in green leafy vegetables, K2 is largely found in animal products and some fermented foods. The body can convert a small amount of K1 to K2, but this process is inefficient, making dietary K2 sources particularly important. The K2 found in animal foods is produced when the animals convert the K1 from their green diets into K2, or by bacterial synthesis during fermentation.

Vitamin K from Cheese and Dairy

Cheese is a notable source of vitamin K2, with content varying by type, fat level, and ripening time. Hard and soft cheeses from grass-fed animals tend to have higher concentrations of K2. The bacterial cultures used in cheesemaking are key to producing menaquinones. High-fat dairy products generally contain more vitamin K2 than low-fat versions because K2 is fat-soluble.

Notable cheese sources of vitamin K2 include:

• Aged Gouda
• Münster
• Brie
• Cheddar
• Emmentaler

Organ Meats: A K2 Powerhouse

Organ meats are exceptionally nutrient-dense and provide some of the most concentrated animal sources of vitamin K2, along with other crucial vitamins and minerals like iron, B vitamins, and protein. The liver is often referred to as 'nature's multivitamin' due to its comprehensive nutritional profile.

Animal foods from organs and other tissues rich in vitamin K2:

• Goose liver pate: This is one of the most potent animal-based sources of K2.
• Beef liver: A single 100-gram serving can provide a significant amount of vitamin K2.
• Chicken liver: A good source of K2, especially for those who consume more poultry.

Eggs and Poultry: Common Dietary Sources

Eggs, particularly the yolks, contain a substantial amount of vitamin K2. The vitamin K content in eggs is highly dependent on the hen's diet, with eggs from pasture-raised hens typically containing higher amounts than those from caged hens. Poultry, such as chicken meat, is also a reliable source of K2. Chicken breast is a readily available and relatively healthy option for boosting K2 intake.

Other Animal Sources

Besides dairy, organ meats, and poultry, other animal products also contribute to vitamin K intake, though in varying amounts.

Additional sources include:

• Pork products: Certain pork products, especially those with higher fat content like sausages and processed meats, contain measurable amounts of K2.
• Beef: While less concentrated than organ meats, beef contributes to K2 intake, especially if it's grass-fed.
• Fish: Certain fatty fish, like salmon and eel, provide some vitamin K2.
• Butter: As a fat-soluble vitamin, K2 is present in butter, especially from grass-fed cows.

K1 vs. K2: Dietary Sources and Benefits

Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Primary Sources	Green leafy vegetables (kale, spinach, broccoli)	Animal products (organ meats, cheese, eggs) and fermented foods (natto)
Metabolism	More involved in blood clotting and is cleared from the blood more quickly	A longer half-life, meaning it stays in the body longer
Health Focus	Crucial for blood coagulation	Supports bone density, cardiovascular health, and calcium regulation
Absorption	Best absorbed when consumed with fat	Found in fatty animal products, aiding its own absorption

The Quality of Animal Products Matters

For the highest vitamin K2 content, the source of the animal product is significant. Animals raised on pasture, with diets rich in grass (which contains K1), produce milk, meat, and eggs with higher levels of vitamin K2 than conventionally raised animals fed grains. Choosing grass-fed beef, pastured eggs, and dairy can thus be a more effective way to boost K2 intake from animal foods.

Conclusion

While leafy greens offer abundant vitamin K1, the more specialized vitamin K2 is predominantly sourced from animal products. For those looking to increase their intake of vitamin K2 for bone and cardiovascular health, incorporating nutrient-dense animal foods is highly effective. The best sources include aged cheeses, organ meats like liver, and poultry, especially from pasture-raised animals. Consuming these foods with their natural fat content can aid in the absorption of this fat-soluble vitamin. A balanced diet incorporating both K1 and K2 sources is ideal for comprehensive health.

For more detailed information on vitamin K and its roles, consult authoritative sources like the NIH Office of Dietary Supplements: ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/

Frequently Asked Questions

Which type of cheese has the most vitamin K2?

Aged, hard cheeses and certain soft cheeses tend to contain the highest levels of vitamin K2. Examples include aged Gouda, Emmentaler, and Münster, with levels depending on factors like bacterial cultures and ripening time.

Are eggs from pasture-raised chickens higher in vitamin K?

Yes, eggs from pasture-raised chickens that eat a diet rich in greens are typically higher in vitamin K2 compared to eggs from conventionally fed, caged hens. This is because the hens convert the K1 from their diet into K2.

Is beef liver a good source of vitamin K?

Yes, beef liver is an excellent and nutrient-dense source of vitamin K2. A 100-gram serving can provide a substantial amount of the vitamin, in addition to other key nutrients.

Does the way an animal is raised affect its vitamin K content?

Absolutely. An animal's diet directly impacts its vitamin K content. Animals that are pasture-raised and consume grass rich in K1 convert it into higher levels of K2, which is then passed on in their meat, dairy, and eggs.

Is vitamin K2 more important than K1?

Both forms of vitamin K are important and play different roles. While K1 is vital for blood clotting, K2 has a more prominent role in bone and cardiovascular health. For optimal wellness, it's beneficial to include sources of both.

How can I maximize the absorption of vitamin K from animal foods?

Since vitamin K is fat-soluble, consuming it along with some dietary fat enhances its absorption. Many animal sources, like cheese and eggs, naturally contain fat, which helps with this process.

Do processed meats like salami contain vitamin K?

Yes, some processed meats like salami contain measurable amounts of vitamin K2. However, these often have high levels of sodium and saturated fat, so they should be consumed in moderation.