Do Prunes Contain Vitamin K2? Fact-Checking This Nutritional Query

January 7, 2026 •

3 min read

While a handful of prunes can provide a significant amount of your daily vitamin K needs, up to 21% of the daily value in just six prunes, the specific type of vitamin K is often misunderstood. So, do prunes contain vitamin K2, or is it a different form of this essential nutrient? It turns out, prunes are a source of vitamin K1, and understanding the difference is key.

Quick Summary

Prunes are a source of vitamin K1, not K2. While K1 supports bone health and blood clotting, K2 is found in fermented and animal-based foods.

Key Points

Not K2, but K1: Prunes are a source of vitamin K1, also known as phylloquinone, not the K2 (menaquinone) form.
K2 Found Elsewhere: Vitamin K2 is primarily sourced from fermented foods (like natto and cheese) and animal products, not fruits or vegetables.
K1 Supports Bones: The vitamin K1 in prunes still plays a crucial role in bone health by activating proteins that help bind calcium.
Other Bone Nutrients: Prunes offer additional bone-supporting nutrients like potassium and anti-inflammatory polyphenols, which contribute to their effectiveness.
Conversion is Inefficient: While the body can partially convert K1 to K2, relying solely on this conversion is not recommended for meeting K2 needs.
Balanced Intake is Best: For optimal bone and heart health, consuming a diverse diet that includes sources of both K1 (like prunes) and K2 (like fermented dairy and meats) is recommended.

The Different Forms of Vitamin K: K1 vs. K2

The vitamin K family includes fat-soluble vitamins vital for blood clotting and bone metabolism. The two main types in our diet are vitamin K1 (phylloquinone) and vitamin K2 (menaquinone).

Vitamin K1 (Phylloquinone)

Vitamin K1 is the most common form, found mainly in plants, including prunes. It is crucial for blood clotting by helping the liver produce prothrombin and aids bone metabolism by activating osteocalcin, which binds calcium to bone. Leafy greens like kale and spinach are excellent K1 sources.

Vitamin K2 (Menaquinone)

Vitamin K2 helps direct calcium to bones and away from soft tissues like arteries. It is primarily found in fermented foods and animal products, not plants. While the body can convert a small amount of K1 to K2, and gut bacteria produce some, this conversion is generally inefficient. Key K2 sources include natto (rich in MK-7), certain cheeses like Gouda and Brie, organ meats, and egg yolks.

The Vitamin K Content of Prunes

Prunes are dried plums and are a good source of vitamin K, but specifically the K1 form. While naturally lacking K2, their high K1 content contributes significantly to bone health. A serving of just five prunes can provide a substantial amount of the recommended daily intake of vitamin K1.

Why Prunes Still Excel at Supporting Bone Health

Prunes are well-known for their positive impact on bone health, even without K2. This benefit comes from a combination of nutrients:

Vitamin K1: Activates osteocalcin, directing calcium to bones.
Polyphenols: These antioxidants in prunes may reduce bone loss by lowering inflammation.
Potassium: Helps maintain bone mineral density by reducing calcium loss.
Boron: Plays a role in bone metabolism and calcium absorption.

Studies, particularly in postmenopausal women, show that daily prune consumption can help maintain bone mineral density and strength.

Comparison Table: Vitamin K1 vs. Vitamin K2


Feature	Vitamin K1 (Phylloquinone)	Vitamin K2 (Menaquinone)
Primary Sources	Green leafy vegetables, plant oils, some fruits like prunes	Fermented foods (natto, cheese), animal products (egg yolks, liver)
Main Function	Primarily involved in blood coagulation	Directs calcium to bones and away from arteries
Absorption	Can be poorly absorbed from plants unless consumed with fat	Generally absorbed more readily by the body, especially longer-chain subtypes
Prune Content	High content	Trace amounts (if any), but some conversion from K1 occurs
Impact on Bones	Critical for activating osteocalcin for bone mineralization	Essential for proper calcium utilization and bone maintenance

Incorporating Prunes and K2 Sources into Your Diet

To get both vitamin K1 and K2, eat a varied diet. Add prunes to your breakfast for K1 and fiber. Include fermented foods or certain cheeses for K2. Pasture-raised egg yolks are also a source of K2. Snacking on prunes with nuts provides K1 and healthy fats to aid absorption. Prunes are valuable for bone health due to K1, potassium, and antioxidants. For more information, visit the National Institutes of Health. {Link: National Institutes of Health https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/}

Conclusion

Prunes primarily contain vitamin K1, not K2. Despite this, they are excellent for bone health due to their mix of vitamin K1, polyphenols, and minerals, shown to help preserve bone density. For optimal vitamin K intake, include K1-rich foods like prunes and K2-rich fermented and animal products in your diet to support bone health and overall well-being.

Frequently Asked Questions

Prunes contain vitamin K1, also known as phylloquinone. This is the form of vitamin K commonly found in plant-based foods.

The best dietary sources of vitamin K2 include fermented foods like natto and sauerkraut, hard and soft cheeses, egg yolks from pasture-raised hens, and organ meats like liver.

Yes, extensive research, including studies on postmenopausal women, has shown that eating prunes daily helps preserve bone mineral density and strength, despite containing K1 instead of K2.

The body can convert a small amount of vitamin K1 to K2, and gut bacteria also produce some K2. However, this conversion process is generally considered to be quite inefficient.

A serving of six prunes provides approximately 21% of the daily recommended intake for vitamin K.

While both are crucial for health, vitamin K1 is primarily involved in blood clotting. Vitamin K2's main function is to help guide calcium to the bones and prevent its buildup in soft tissues like arteries.

In addition to vitamin K1, prunes contain beneficial compounds such as polyphenols (with anti-inflammatory properties), potassium, and boron, which all contribute to maintaining healthy bones.