Although vitamin K2 is relatively unknown compared to the well-known vitamins A, B, C, and D, it is a highly regarded vitamin in the field of "healthy nutrition," which is attributed with many beneficial effects. It is a helpful aid in supporting blood clotting, strengthening bones, and preventing arteriosclerosis and cancer.
The following article will take a closer look at this vitamin and clarify the effects of a vitamin K2-rich diet for you, distinguishing between scientifically proven and not fully scientifically proven effects. In addition, the individual foods and their share of vitamin K2 will also be determined.
Summary:
- Vitamin K2, also known as menaquinone, is part of the vitamin K group and, like vitamins A, D, and E, belongs to the fat-soluble vitamins. Due to its importance in blood clotting and its other positive effects on bones and arteries, it is of central significance for the human body.
- The foods that contain vitamin K2 can be roughly divided into three groups. These are animal products, such as organs, meat, and eggs, fermented dairy products, such as cheese and yogurt, and green leafy vegetables, such as kale or spinach.
- A deficiency of vitamin K2 is relatively rare. If the case arises, vitamin K2 supplements are also recommended as dietary supplements. Here, precise age- and disease-related dosage should be observed.
Foods with Vitamin K2: What you should know
To understand the importance of vitamin K2 in the diet and for the human body, it should be analyzed and described in detail in the first part. Subsequently, the various foods and their properties are presented in a second part.
What is Vitamin K2?
Together with vitamins K1 and K3, vitamin K2 forms the vitamin K group, which, like vitamins A, D, and E, belongs to the fat-soluble vitamins.
The K vitamins have a common chemical structural element, the 2-Methyl-1,4-Naphthoquinone, and differ only by the lipophilic side chain. Vitamin K2 is also called menaquinone and is either produced by bacteria or synthesized by humans and animals themselves from vitamin K1.
The term Vitamin K2 is a collective term that refers to various menaquinones (from Menaquinone-4 to Menaquinone-10).
In terms of chemical composition, these menaquinones differ only slightly due to their varying length of side chains, which is why they reflect the same vitamin.
However, they can differ greatly in their effects, with some Menaquinones having a much greater potential in the Gamma-Carboxylation of proteins.
The different menaquinones are often abbreviated with "MK" and the respective number. The most well-known Mk, which are also attributed to have a great effect in supporting blood clotting and strengthening bones, are Mk-4 and Mk-7.
Why do Foods with Vitamin K2 Have Positive Effects?
What are the causes and underlying relationships of the effects of Vitamin K2? What is the reason that it supports blood clotting? The answer to this lies in the aforementioned Gamma-Carboxylation of proteins, in which Vitamin K2 plays a crucial role. Overall, fourteen proteins depend on Vitamin K, six of which are involved in blood clotting.
Through the interaction of different proteins and vitamin K2, the various health effects of vitamin K2 can be explained.
Gamma-carboxylation and vitamin K2 convert clotting factors into their active form and support osteocalcin in binding calcium. This explains the importance of blood clotting and bones.
In addition, vitamin K2 activates so-called matrix Gla proteins, which prevent calcification and convert the protein Gas6, which protects cells, into its active form. This also explains the preventive effect on arteriosclerosis and cancer.
What Foods contain Vitamin K2?
As we have already mentioned, the vitamins of the K group differ in their process of formation and their different stages of production. As a result, they are also contained in different types of food.
The vitamin K1, also known as Phylloquinone, is produced by plants and is therefore often found in the chloroplasts of green plants.
For this reason, it is also mainly found in green vegetables, such as spinach, broccoli, or kale. However, other plant foods, such as oils, fruits, cereals, black tea, and legumes, also contain it.
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| Vitamin K is found in large quantities in vegetables. However, vitamin K1 is predominant here. However, vitamin K2 is also found in fermented vegetables such as sauerkraut, natto, or kimchi. |
The vitamin K2, which is in turn produced by bacteria, often also intestinal bacteria, is, therefore, more abundant in animal or fermented foods. Examples would be yogurt, cheese, egg yolks, or meat.
What Foods contain the most Vitamin K2?
The following is an overview of foods with high vitamin K2 content. To put these numbers in the right context, it should be mentioned again that the human body needs significantly less vitamin K2 than vitamin K1 and the daily requirement for a man between 15 and 50 years old is approximately 70 ug.
| Serving (100 g) | Food | Item Vitamin K2 content in micrograms |
|---|---|---|
| 1 Serving | Natto | 108 |
| 1 Serving | Beef Liver | 74 |
| 1 Serving | Eel | 63 |
| 1 Serving | Butter | 60 |
| 1 Serving | Chicken Egg | 48 |
| 1 Serving | Cream Cheese | 30 |
| 1 Serving | Feta Cheese | 30 |
As the table illustrates, except for Natto, vitamin K2 is predominantly found in animal foods. Vitamin K1, on the other hand, is strongly present in green vegetables and in significantly larger amounts than K2 in animal foods.
However, this is not a coincidence, on the contrary, there is a connection here. As farm animals often feed on green vegetables with a high vitamin K1 content, they convert and store vitamin K1 into vitamin K2.
Since Vitamin K1 and vitamin K2 are strongly interconnected and work together, foods that contain a lot of Vitamin K in general also play a role in Vitamin K2 supply.
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| Especially in the egg yolk is a lot of Vitamin K2. |
Since there are foods here that are not yet mentioned in the previous table but have a very high Vitamin K content, the following table is intended to provide a further overview.
| Serving (100 g) | Food | Item Vitamin K2 content in micrograms |
|---|---|---|
| 1 Serving | Kale, Chicken Hearts | 600 to 1000 |
| 1 Serving | Spinach, Broccoli, Chickpeas, Brussels Sprouts, Chives, Parsley, Black Tea, Fennel | 200 to 600 |
| 1 Serving | Canola Oil, Pumpkin Seed Oil, Mung Beans, Lentils, Lettuce | 100 to 200 |
| 1 Serving | Liver, Oatmeal, Peas, Cauliflower, Chinese Cabbage | 50 to 100 |
| 1 Serving | Olive Oil, Corn, Green Beans, Asparagus, Black Currant, Kiwi, Honey, Cashews | 20 to 50 |
| 1 Serving | Pork, Beef, Cucumber, Bell Pepper, Avocado, Zucchini, Red Currant, Grape, Raspberry, Coffee | 10 to 20 |
| 1 Serving | Butter, Cheese, Bread, Flaxseed, Tomatoes, Potatoes, Cherry, Pear, Apple, Walnut, Hazelnut | 1 to 10 |
| 1 serving | Milk, Yogurt, Grape Juice, Pineapple, Eggplant | Less than 1 |
Comparing the two tables, it becomes clear again that higher levels of Vitamin K2 are mainly found in animal foods. However, it would be wrong to conclude from this that vitamin K is generally found mainly in animal foods.
This is shown again in the second table, there are a lot of plant-based foods that have a very high Vitamin K content, which is due to the relatively high proportion of vitamin K1.
What are the Consequences of a Vegan diet on the Vitamin K2 Balance?
As previously established, Vitamin K2 is primarily found in animal-based foods. For this reason, it's reasonable to assume that vegans may be deficient in this vitamin. However, there is a mechanism that prevents this from happening.
The human body is capable of converting Vitamin K1 into Vitamin K2 through its gut bacteria. As we have seen, there are many vegan plant-based foods with high Vitamin K1 content, such as legumes, leafy green vegetables, nuts, etc. Since vegans consume these foods in high amounts, there should be no deficiency in this area.
What should I consider in terms of Vitamin K2 when it comes to my Diet?
Since the daily requirement for Vitamin K2 is relatively low and it occurs in small amounts in food, both a deficiency and an overdose in a healthy person are very unlikely. Therefore, there are no particularly strict guidelines that you need to follow.
In addition, Vitamin K is quite stable when it comes to various preparation methods. It is rarely lost due to heat and oxygen. However, you should be cautious with longer storage times due to the light sensitivity of Vitamin K.
What tips are there for a healthy diet with sufficient Vitamin K2?
Since foods high in Vitamin K are very versatile and can be found in both animal and plant-based sources, it's easy to create various healthy meals with them. Especially when looking at the tables above, the ingredients can be distributed very well throughout the three meals of the day: breakfast, lunch, and dinner.
For breakfast, a rich cereal with yogurt, oatmeal, apples, black currants, and various nuts would be a great option. In addition to its high Vitamin K content, this breakfast would also be very rich in vitamins and fiber.
For lunch, you could put together a carbohydrate-rich meal from legumes or potatoes with leafy green vegetables such as spinach or kale. For dinner, a protein-rich and healthy diet with liver or meat, bread with cheese and parsley, and a field salad with cucumber, bell pepper, and avocado would be advisable.
Can vitamin K2 supplements be alternatives?
It often seems more practical and easier to reach for dietary supplements instead of dealing with different foods and their ingredients. Therefore, in the following, it will be examined whether vitamin K2 supplements would also be a suitable means to meet your daily needs.
What are the benefits of vitamin K2 supplements?
A deficiency of vitamin K2 solely due to improper nutrition is rather unlikely, which is why additional supplementation through supplements is rather counterproductive for healthy individuals.
For healthy individuals, the rule, therefore, applies that they do not require vitamin K2 in the form of dietary supplements, even though certain advertisements may suggest the use of vitamin K2 for alleviating and preventing diseases.
If certain diseases or symptoms are deficient in inhibited blood clotting or brittle bones occur, it is always advisable to discuss the possibility of vitamin K supplementation with your doctor beforehand.
A well-known and frequently used dietary supplement is MK-7, which achieves a stable serum level and ensures strong carboxylation of osteocalcin. But what does a deficiency in vitamin K2 mean, and how can it occur?
What are the Causes and consequences of a Deficiency in Vitamin K2?
A deficiency in Vitamin K or Vitamin K2 is rare among healthy individuals. Therefore, it is unlikely that a specific diet would result in a deficiency in Vitamin K2. The German Society for Nutrition estimates the daily requirement for men between the ages of 15 and 50 to be 70 μg and for men over 51 to be 80 μg. For women in these two age groups, it is 60 μg and 65 μg respectively.
Since a deficiency due to nutrition is unlikely in healthy individuals, this is more likely to be caused by disorders and external factors. Disorders that impede the normal utilization of vitamin K2 could be certain diseases such as chronic gastrointestinal disorders or chronic liver damage.
External causes can be found in certain medications such as antibiotics, drugs for tuberculosis, or drugs that inhibit blood clotting.
Although a deficiency is rare, it has serious consequences. Since blood clotting is a factor that affects all organs, various health problems and symptoms could arise. In addition to the gastrointestinal tract, liver, and kidneys, the skin, mucous membranes, and brain could also be affected by the damage.
What disadvantages can Vitamin K2 supplements have?
It can only be harmful in certain exceptional cases. For example, if you are taking certain Vitamin K antagonists such as Marcumar to prevent thrombosis, an additional intake of Vitamin K2 could significantly impair the success of the therapy. Even 10 μg can have a negative impact in this case.
The Federal Institute for Risk Assessment (BfR) has therefore proposed a maximum amount of only 80 µg K1 and 25 µg K2 as a daily dose for dietary supplements. In addition, there are warning notices on the packaging regarding the simultaneous use of anticoagulant medications.
Why should I take vitamin K2 supplements together with Vitamin D3?
Vitamin K2 and vitamin D3 mutually enhance their effects. The reason for this lies in the fact that they are both responsible for bone health and calcium utilization. Vitamin D3 first ensures the absorption of calcium, i.e., the transport of calcium into the blood, while vitamin K2, in turn, helps the bones to absorb and utilize the calcium.
The activation of the protein osteocalcin by vitamin K2 is also crucial. Once the body has absorbed calcium, with the help of vitamin D3, osteocalcin helps to actively bind the calcium to the bones.
Conclusion
In conclusion, it can be stated that vitamin K2 is an interesting and healthy vitamin that can have a positive effect on the body in many ways. To incorporate it well into one's diet, it is important to differentiate between vitamin K1 and vitamin K2, as vitamin K1 is mainly found in green vegetables, and vitamin K2 is mainly found in animal-based foods.
In general, a deficiency is unlikely in healthy people, so you usually don't have to worry about whether your diet contains enough Vitamin K2 or whether you should supplement it with Vitamin K2 preparations.
Nevertheless, it is useful to know which foods contain a lot of vitamin K2, as in certain cases, such as chronic gastrointestinal diseases, vegan diets, or certain medications, you should keep an eye on your vitamin K2 levels.