Does grass-fed beef have K2?

December 19, 2025 •

4 min read

According to nutrition experts, grass-fed beef is significantly more nutritious than grain-fed beef, particularly due to higher levels of vital nutrients like Vitamin K2. The primary reason for this difference is the cow's natural diet of chlorophyll-rich grass, which is converted into Vitamin K2 during digestion.

Quick Summary

Grass-fed beef contains measurable amounts of Vitamin K2, a fat-soluble nutrient important for bone and heart health. The animal's diet of pasture grass rich in Vitamin K1 is converted into K2 (MK-4 menaquinone) and stored in its fat and organs. Grain-fed beef has very little or no Vitamin K2.

Key Points

Source of K2: Grass-fed beef is a natural source of Vitamin K2, unlike grain-fed beef.
K1 to K2 Conversion: Cattle efficiently convert Vitamin K1 from grass into Vitamin K2 (MK-4).
Highest Concentrations: The highest levels of K2 in beef are found in the fat and organ meats, such as the liver.
Health Benefits: The K2 in grass-fed beef supports bone density and protects against arterial calcification.
Dietary Impact: The K2 content can vary based on seasonal grazing and the cow's diet history.
Check the Label: To ensure high K2 content, look for beef that is certified as 100% grass-fed and grass-finished.
Fat-Soluble Nutrient: Because K2 is fat-soluble, consuming the fat from grass-fed beef is key to getting the nutrient.

Understanding Vitamin K: K1 vs. K2

Before delving into the specifics of grass-fed beef, it is crucial to understand the two main types of Vitamin K: K1 (phylloquinone) and K2 (menaquinone). While both play important roles in the body, their dietary sources and functions differ significantly.

Vitamin K1: This form is found abundantly in green, leafy vegetables such as kale, spinach, and Swiss chard. It is primarily involved in blood coagulation and clotting.
Vitamin K2: This lesser-known form is found mainly in animal products and fermented foods. Its key function is to regulate where calcium is deposited in the body, ensuring it goes to the bones and teeth rather than accumulating in soft tissues like arteries.

The Grass-Fed Advantage: A Natural K2 Pathway

The link between grass-fed beef and Vitamin K2 production is rooted in a cow's natural biology. When a cow consumes grass and other green forages, its body ingests large amounts of Vitamin K1. The animal's digestive system, specifically its gut bacteria, is highly efficient at converting this K1 into the highly bioavailable MK-4 form of Vitamin K2. This MK-4 is then stored in the animal's fatty tissues and organs. In contrast, grain-fed cattle, whose diet lacks significant amounts of K1, produce much lower amounts of K2. This dietary difference creates a cascade effect on the nutritional composition of the meat.

Where to Find K2 in Grass-Fed Beef

Since Vitamin K2 is fat-soluble, it is not evenly distributed throughout the animal's body. The highest concentrations are found in the fat and organ meats. Beef liver, for instance, is a particularly nutrient-dense source of Vitamin K2. The fat marbled throughout the muscle meat, as well as products like grass-fed tallow, will also contain significant amounts. This is why consuming a variety of grass-fed products, including organ meats, is often recommended for those seeking to maximize their K2 intake from beef.

How Seasonal Variations Affect K2 Content

The nutritional profile of grass-fed beef can vary depending on the season and the quality of the pasture. Cattle grazing on lush, nutrient-dense pastures during the spring and summer will likely have higher levels of Vitamin K1 in their diet. This, in turn, can lead to higher concentrations of K2 in their meat and dairy products. Conversely, beef from cattle that are finished on grain or are not on pasture year-round may have less consistent and lower K2 levels. Supporting local farmers who prioritize soil quality and year-round grazing can help ensure a more consistent K2 content.

Grass-Fed vs. Grain-Fed: A Nutritional Comparison


Nutrient	Grass-Fed Beef	Grain-Fed Beef
Vitamin K2 (MK-4)	Significantly higher in fat and organs	Negligible or absent
Omega-3 Fatty Acids	Higher levels, more desirable ratio to omega-6	Higher levels of omega-6, often imbalanced ratio
Conjugated Linoleic Acid (CLA)	Higher concentrations (2-3x)	Lower concentrations
Antioxidants (Vitamin E)	Higher levels of fat-soluble antioxidants	Lower levels
Beta-carotene (Pro-Vitamin A)	Higher levels due to grass diet	Lower levels

The Health Implications of K2

Consuming a diet rich in Vitamin K2 is associated with several health benefits, many of which are linked to its role in calcium metabolism. Proper calcium deposition is crucial for:

Bone Health: K2 ensures calcium is integrated into bone tissue, which is vital for maintaining bone density and reducing the risk of osteoporosis.
Heart Health: By preventing calcium from accumulating in the arteries, K2 helps reduce the risk of arterial calcification and cardiovascular disease.
Dental Health: Some research suggests K2 may play a role in dental health by promoting the proper mineralization of teeth.

These benefits highlight why sourcing high-quality, grass-fed beef can be a valuable part of a balanced diet focused on nutritional completeness. While supplementation is an option, obtaining nutrients from whole food sources like grass-fed beef ensures they are consumed along with other synergistic nutrients like Vitamins A, D, and E. For more information on the role of nutrition in health, consider consulting resources like the Weston A. Price Foundation, a non-profit organization dedicated to restoring nutrient-dense foods to the human diet.

Conclusion: The Final Verdict on Grass-Fed Beef and K2

To answer the question, yes, grass-fed beef does have K2, and in significantly higher amounts than its grain-fed counterpart. This difference is a direct result of the cow's natural diet of green grass, which contains K1 that is then converted to K2. The K2 is stored primarily in the fat and organ meats, making these parts the most potent sources. Including high-quality, 100% grass-fed beef in your diet can be a natural way to increase your intake of this important nutrient, supporting optimal bone and heart health. When shopping, look for certified 100% grass-fed products to ensure the cattle were not finished on grain, which would reduce the K2 content.

Frequently Asked Questions

Vitamin K2, or menaquinone, is a fat-soluble vitamin primarily known for activating proteins that help with calcium metabolism. It directs calcium to your bones and teeth while preventing its buildup in soft tissues like arteries and kidneys.

The difference lies in the cow's diet. Grass-fed cattle consume a large amount of green grass rich in Vitamin K1, which their digestive systems efficiently convert into K2. Grain-fed cattle, lacking this diet, do not produce significant amounts of K2.

As a fat-soluble vitamin, K2 is concentrated in the fatty tissues and organs of the animal. Therefore, the highest levels are found in grass-fed beef liver, fat, and bone marrow.

While grass-fed beef is a good source of K2, particularly in its organ meats and fat, it's beneficial to include other sources as well, such as grass-fed dairy products (butter, cheese), pastured eggs, and fermented foods like natto.

MK-4 is the specific type of K2 produced by animals and found in grass-fed beef, while MK-7 is a longer-chain menaquinone typically produced by bacteria and found in fermented foods or supplements. Both forms have important functions in the body, but some researchers suggest MK-4 may be more readily utilized by certain tissues like the brain and bones.

As a fat-soluble vitamin, K2 is relatively stable during cooking. However, high heat and prolonged cooking times can lead to some nutrient degradation. To preserve K2, especially in cuts with higher fat content, it is best to cook at moderate temperatures.

Look for products explicitly labeled "100% Grass-Fed" or "Grass-Finished." It is also helpful to buy from local farmers or trusted suppliers who can provide information on their cattle's complete diet, ensuring they were not finished on grain.