Vitamin K is an essential, fat-soluble nutrient our body needs for functions like healthy blood clotting. It comes in two forms:
- Vitamin K1, (phylloquinone) found in leafy greens, vegetables, and some plant oils
- Vitamin K2, (menaquinone) found in dairy, fermented foods, and animal products
You can also get vitamin K supplements, but clinical trials show that the vitamin K we consume from food is more effective in our bodies. Our bodies make some vitamin K in the colon, and most people get the rest of what they need from their diet.
Why You Need Vitamin K2
Both vitamins K1 and K2 ensure healthy blood clotting, preventing excessive bleeding and bruising when blood vessels get injured. But recent research suggests that they play different roles in other aspects of our health, with vitamin K2 adding health benefits independent of K1.
However, there is not yet a recommended intake set specifically for vitamin K2. You should get between 90 and 120 micrograms of vitamin K — but this requirement is based on the vitamin K1 needed to prevent bleeding.
Scientists studying vitamin K2’s effects suggest its benefits come with a daily intake of between 10 and 45 micrograms. But in the average diet, about 90% of the vitamin K consumed is K1.
Getting vitamin K2 in our diets supports:
Vitamin K breaks down calcium in our bodies, and this effect helps prevent hard deposits (calcium and fatty material) from forming in artery walls. Smooth and flexible blood vessels ensure healthy circulation, reducing the risk of harmful blood clots and heart disease.
This effect may come from vitamin K2 alone, however. Studies show that a person’s risk of dying from heart disease falls by 9% for every 10 micrograms consumed a day, but found no association with K1 intake.
Our bodies need calcium to build and maintain bones. When it breaks down calcium in our bodies, vitamin K2 activates a protein that helps the mineral bind to our bones to do its job.
Researchers have found that vitamin K2 may slow or stop cancer cell activity.
Other studies show this may improve survival rates and reduce cancer’s recurrence. However, these studies have focused on only certain cancers, like liver and prostate, so much more research is needed.
Foods With Vitamin K2
Vitamin K is in many foods, but on average, most of what we consume is the K1 form found in plants. These eight vitamin K2-rich foods can help you achieve a better balance in your diet.
Natto is a Japanese dish made from fermented soybeans. It’s high in many nutrients that promote good gut health and is the richest source of vitamin K2 available. A 100-gram serving contains 108 micrograms of vitamin K2, more than twice the recommended intake.
Though most vitamin K2 sources are animal-based, eel offers a seafood alternative. There are 63 micrograms in a 100-gram serving of eel, meeting your recommended level for the day.
Cheeses are one of the best sources of vitamin K2 along with nutrients like calcium, vitamin A, and protein. However, they’re also high in saturated fats and calories, so you should moderate your portions. Vitamin K2 content varies based on the cheese, and it increases with age across all types. Common cheeses with the highest amount of vitamin K2 per 50-gram serving include:
- 50 micrograms in Munster
- 34 micrograms in Camembert
- About 32 micrograms in Edam and aged Gouda
- 12 micrograms in cheddar
4. Beef Liver
Beef liver is one of the most nutritious meat products you can eat, containing your entire daily requirement for nutrients like vitamin A, riboflavin, folate, and copper. A 100-gram serving also has more than 11 micrograms of vitamin K2, making it the best meat-based source of the vitamin.
Just a tablespoon of butter has 2.1 micrograms of vitamin K2. However, that same tablespoon contains about 100 calories and 11 grams of fat, so make sure to keep your servings small to avoid potential health risks and unwanted weight gain.
Sauerkraut is fermented cabbage with a distinctive sour flavor. Like with natto, this fermentation process offers many health benefits, like promoting good gut health and boosting immunity. With 2.75 micrograms per half-cup, sauerkraut is also a great source of vitamin K2.
8. Egg Yolk
An egg yolk can contain between 67 and 192 micrograms of vitamin K2. This amount depends on what the hen eats, however. Most chicken feed today is fortified with vitamin K, and this content passes onto the egg. But chickens fed corn or soy-based diets are more at risk of vitamin K deficiencies.