Can I get enough K2 from my diet?

December 9, 2025 •

3 min read

According to Healthline, the average intake of vitamin K2 is incredibly low in the modern diet, making it difficult for many people to get enough from food alone. So, can I get enough K2 from my diet? The answer depends heavily on your specific food choices and whether you consume the right fermented and animal-based products regularly.

Quick Summary

This article explores the best dietary sources of vitamin K2, contrasting fermented foods like natto with animal products and addressing the body's inefficient conversion of K1 to K2. It details daily recommendations and potential supplementation needs to support bone and heart health.

Key Points

Dietary intake is often insufficient: For most Western diets, it's challenging to get enough vitamin K2 from food alone due to limited consumption of key sources like natto and fermented products.
Natto is the most potent source: The Japanese fermented soybean dish, natto, contains exceptionally high levels of the MK-7 form of K2.
Animal products provide K2 (MK-4): Sources like liver, eggs, and grass-fed butter are rich in the MK-4 subtype of vitamin K2.
Supplementation is a practical option: For those unable to meet their needs through diet, supplements offer a convenient and effective way to ensure adequate K2 intake.
K2 supports bone and heart health: It works by directing calcium to bones and away from arteries, a process that relies on its activation of specific proteins.
Absorption differs for K1 and K2: K2 is absorbed more readily than K1 from leafy greens, making K2-rich foods or supplements more efficient for raising tissue levels.

Understanding Vitamin K: K1 vs. K2

Vitamin K is a group of fat-soluble vitamins, primarily consisting of K1 (phylloquinone) and K2 (menaquinone). Vitamin K1, found in leafy greens, is mainly involved in blood clotting. Vitamin K2 is crucial for bone and heart health by helping to direct calcium deposition. It is found in fermented foods and animal products, and while the body can convert some K1 to K2, this conversion is often inefficient.

The Rich Rewards of Fermented Foods

Fermented foods, particularly natto, are the most concentrated dietary source of vitamin K2, specifically the MK-7 subtype. A single tablespoon of natto can exceed the suggested daily intake. Other fermented foods like sauerkraut and certain cheeses also contain K2, but in much lower amounts. Bacteria involved in the fermentation process synthesize these menaquinones.

Animal-Based Sources of K2 (Menaquinone-4)

Animal products are key sources of the MK-4 subtype of vitamin K2, produced by the conversion of K1 within animal tissues.

Organ Meats: Liver is a particularly good source of MK-4.
Eggs: Yolks from free-range chickens contain moderate levels of MK-4.
High-Fat Dairy: Grass-fed dairy like butter and certain cheeses (Gouda, Brie) are good sources.
Meat: Chicken and beef also contain K2, though in lower concentrations.

Can Diet Alone Suffice? A Closer Look

For most individuals following a typical Western diet, obtaining sufficient K2 from food alone for optimal health is challenging. The average intake is low, and high-K2 foods like natto are not commonly consumed. While some K2 comes from animal products and cheese, it's often not enough to reach beneficial intake levels. Supplementation may be necessary for those with low intake of high-K2 foods or certain health conditions. The synergy between vitamins K2 and D is also vital for effective calcium metabolism.

K2 and Other Health Benefits

Vitamin K2 is linked to health benefits beyond bone and cardiovascular health. It may support cellular energy production, act as an antioxidant, and potentially offer protection against certain cancers. K2 activates proteins like Matrix Gla Protein (MGP) and osteocalcin, which are essential for proper calcium utilization and preventing vascular calcification.

Comparison of K2 Sources: Diet vs. Supplements


Feature	Diet (Natto, Fermented Foods)	Diet (Animal Products)	K2 Supplements	Importance for Intake
Primary K2 Form	Long-chain menaquinones (e.g., MK-7)	Short-chain menaquinones (MK-4)	Varies (MK-4, MK-7)	Very High
K2 Concentration	Exceptionally high in natto	Moderate in organ meats/high-fat dairy	Standardized and potent	High
Absorption Rate	Readily absorbed, especially MK-7	Efficient absorption (fat-soluble)	High absorption	High
Convenience	Low, especially for natto in Western diets	Variable, depends on dietary habits	High, easy to take daily	Very High
Taste Profile	Strong, distinct, often unappealing (natto)	Generally palatable (cheese, butter)	Tasteless in capsules	Depends on personal preference
Synergy with D3	Yes, if paired with Vitamin D-rich foods or sun exposure	Yes, if paired with Vitamin D-rich foods or sun exposure	Easy to find D3+K2 combination supplements	Very High
Risk of Overdose	Very low	Very low	Low, but consult a doctor	Low
Suitability for Western Diets	Low due to cultural food preferences	Moderate, but requires specific food choices	High, bridges dietary gaps effectively	High

Conclusion: Can I Get Enough K2 From My Diet?

While it is possible to get enough vitamin K2 from diet alone, it's often difficult for those with a typical Western diet. Achieving optimal levels requires consistent consumption of specific foods like natto, hard cheeses, and organ meats. For most people, particularly those focused on bone and heart health, a high-quality vitamin K2 supplement is a practical solution to ensure adequate and consistent intake, especially if these foods are not regularly consumed. Consult a healthcare professional before starting any new supplement, particularly if taking blood-thinning medications.

Learn more about the biochemistry of Vitamin K

Frequently Asked Questions

MK-4 is found in animal products and has a shorter half-life, while MK-7 is prominent in fermented foods and has a longer half-life, staying in the body for longer. For sustained benefits, MK-7 is often favored, but both forms have important biological functions.

A vegetarian diet makes it harder to obtain sufficient K2, as the richest food sources are natto and animal products. Natto is the main high-concentration fermented vegetarian option. Vegetarians may need to consider supplementation to meet their K2 needs.

While gut bacteria do produce some vitamin K2, the amount is often insufficient to meet optimal health needs, especially considering variations in gut health and the effects of antibiotics.

Vitamin K2 supplements are generally considered safe. However, if you are taking blood-thinning medications like warfarin, it is crucial to consult a healthcare provider before taking any vitamin K supplement, as it can interfere with their function.

Serious vitamin K deficiency is rare, but symptoms can include uncontrolled bleeding, easy bruising, and small bruises under the nails. A suboptimal intake can also impact long-term bone density and heart health without immediate symptoms.

Because vitamin K is fat-soluble, consuming K2-rich foods with a source of fat, such as grass-fed butter, egg yolks, or oils, can enhance absorption.

Yes, vitamin K2 and vitamin D have a synergistic relationship. They work together to metabolize calcium effectively, and optimizing both is important for bone and cardiovascular health.