Feta's Vitamin K2 Content: The Surprising Truth
Despite being a fermented dairy product, feta's vitamin K2 content is remarkably low compared to many other cheeses. Vitamin K2, or menaquinone, is produced by bacteria during the fermentation and aging process, and the specific microbial cultures and ripening times used for feta result in minimal production of this vital nutrient. Studies comparing various cheeses have consistently shown that Mediterranean cheeses, including feta, rank at the low end of the spectrum for menaquinone levels. For those relying on cheese as a primary source of K2, feta is not the best choice, though it remains a delicious and nutritious option for other reasons.
Why Feta Contains Very Little Vitamin K2
There are several factors contributing to feta's low vitamin K2 levels:
- Shorter ripening time: Unlike aged cheeses that ripen for months or even years, feta ripens for a relatively short period. This shorter duration limits the time available for K2-producing bacteria to multiply and synthesize menaquinones.
- Microbial cultures: The specific lactic acid bacteria cultures used to make feta are less efficient at producing the long-chain menaquinones (like MK-7, MK-8, and MK-9) found in aged cheeses.
- High moisture content: Feta's high moisture and low-fat content also plays a role, as vitamin K2 is a fat-soluble vitamin. Dairy products with higher fat concentrations and less water tend to have higher levels of K2.
Cheeses with Higher Vitamin K2
For those seeking to increase their dietary intake of vitamin K2 through cheese, the best options are hard, aged, and certain soft fermented cheeses. The fat content and maturation time are key indicators of higher K2 levels.
- Hard cheeses: Aged Gouda, Edam, and certain Swiss varieties like Emmental and Raclette are particularly rich sources. A study published in Nutrients highlighted Gouda and Edam as excellent sources.
- Soft fermented cheeses: Some soft, mold-ripened cheeses like Brie and Camembert can also provide a notable amount of K2, especially when made with mesophilic cultures.
- Blue cheese: Varieties like Stilton and Roquefort contain moderate to high levels of K2, primarily the long-chain menaquinones synthesized by the specific bacteria involved in their production.
A Comparison of K2 in Cheeses
To put the K2 content into perspective, the table below compares the approximate total menaquinone content per 100 grams for feta and other notable cheese varieties, based on research findings.
| Cheese Type | Texture | Approximate Total K2 (ng/g) |
|---|---|---|
| Feta | Soft/Crumbly | ~117 |
| Münster | Soft | ~801 |
| Aged Gouda | Hard | ~729 |
| Camembert | Soft | ~681 |
| Stilton | Blue | ~494 |
| Emmental | Hard | ~433 |
| Cheddar | Hard | ~235 |
How to Boost Your Vitamin K2 Intake
If you're not a fan of aged cheese or want to diversify your K2 sources, there are many other options available, including animal products and other fermented foods. For a comprehensive overview of menaquinone content in various foods, including dairy, you can consult research published by the National Institutes of Health.
Animal Products:
- Natto: A traditional Japanese fermented soybean dish, natto is by far the richest source of K2, specifically the MK-7 variant.
- Grass-fed butter: Butter from cows fed on pasture contains higher amounts of the MK-4 menaquinone.
- Egg yolks: Eggs from pasture-raised chickens are a great source of K2.
- Organ meats: Goose and chicken liver pâté are excellent sources of K2.
Other Fermented Foods:
- Sauerkraut: Fermented cabbage can contain small to moderate amounts of K2, depending on the fermentation process.
- Kefir and yogurt: Full-fat, traditionally fermented kefir and yogurt can also contribute small amounts of K2, particularly from mesophilic cultures.
Conclusion: Feta's Place in a K2-Rich Diet
To conclude, feta cheese is not a good source of vitamin K2 for dietary purposes. The aging and fermentation processes it undergoes differ significantly from those that produce high levels of menaquinones in aged hard cheeses. While feta is a healthy food with other benefits, if your goal is to boost K2 intake, you should focus on other options. Aged cheeses like Gouda, certain soft ripened cheeses, and other fermented foods like natto are far more effective dietary sources. Combining these foods with adequate healthy fats will ensure optimal absorption of this fat-soluble vitamin.
Menaquinone Content of Cheese - PMC
Feta's Role in a Balanced Diet
Despite its low K2 content, feta remains a nutritious component of a Mediterranean-style diet, offering calcium, protein, and probiotics. It should be enjoyed for its unique flavor and other health benefits, but not as a primary K2 source.
Beyond Cheese: Expanding Your K2 Horizon
For a truly K2-rich diet, looking beyond cheese is essential. Incorporating foods like natto, grass-fed butter, and egg yolks from pasture-raised hens provides a more diverse and potent source of this important nutrient. This ensures you receive both the MK-4 and MK-7 forms of vitamin K2.
Maximizing Vitamin K2 Absorption
Since vitamin K2 is fat-soluble, consuming it with dietary fat is crucial for optimal absorption. Pairing your chosen K2-rich foods with healthy fats like olive oil or avocado can enhance their benefits. For example, grating some aged Gouda over a salad with a simple olive oil vinaigrette is an effective combination.
The Spectrum of Fermentation and K2 Production
Not all fermentation is equal when it comes to K2 synthesis. The bacterial cultures and environmental conditions play a significant role. This explains why fermented products like natto are exceptionally high in K2, while others, like many yogurts and even feta, produce much less. Understanding this distinction is key to making informed dietary choices.
Monitoring Vitamin K2 Intake
As there is no universal daily recommendation for K2, focusing on a diverse diet rich in known sources is the best approach for most people. While supplementation is an option, a food-first strategy is often preferred. Always consult a healthcare professional before starting any new supplement regimen.
Final Takeaway
Feta cheese is not a high-K2 food. For significant vitamin K2 intake, prioritize aged hard cheeses like Gouda or Emmental, as well as fermented soybeans (natto), grass-fed butter, and pasture-raised eggs.
