Best Way to get Vitamin K With Food

Vitamin K is an important nutrient for your bones. But is that just one more supplement you need to add to your growing at-home dispensary? What is the best way to get vitamin K from food?

For starters, vitamin K is not just one vitamin. It exists in several different forms, and they don’t all come from the same foods.

Let’s break it down so you know exactly what foods to eat.

The Different Forms of Vitamin K

There are 3 forms of vitamin K, and one of those forms has about 10 subtypes. Here’s the quick picture:

Phylloquinone, also known as K1, is the form we are most familiar with. This form is created by plants.

Menaquinone is another form of vitamin K, also called K2. And here’s the catch – there are about 10 different types of menaquinone. K2 is created in animal tissues (meat, milk and eggs) and by bacteria.

MK4 is considered a short chain menaquinone. It is the preferred form for most of your organs and tissues to store vitamin K2. 

As the MK number gets higher, the length of the menaquinone gets longer. So MK5 is longer than MK4, and they get longer as it goes up from there.

MK4 and MK7 are the forms of menaquinone with the most research related to bone health. In this article I’ll cover food sources of MK4, MK7 and some other long-chain forms of menaquinone.

Menadione, also known as MK3, is the third form of vitamin K. It is an intermediate form that is made in your body when vitamin K is metabolized. It’s also used in animal feed. Humans don’t need to consume K3 at all.

Read The Vitamin K Roadmap to really dig into the details of the different forms of vitamin K.

Best Food Sources of K1

Let’s start with phylloquinone, or K1. The RDA for vitamin K1 is 90 mcg for adult females, and 120 mcg for adult males. However, this is based on the amount that is needed for normal blood clotting. Research suggests you need a larger amount, about 200 mcg/day, to support your bones (1).  

You get K1 from eating plants, especially leafy green vegetables. It’s also present in some vegetable oils (2). As you can see from the chart below, it’s not hard to get 200 mcg/day of K1.

Best Food Sources of MK4

Remember, humans and animals can convert all the other forms of vitamin K to MK4. Since this is the storage form for vitamin K, you can get MK4 by eating meat, milk and eggs (3).  

Here are the amounts of MK4 that you can get from various animal products (4). Notice the amounts are in micrograms:

The amount of MK-4 in a food differs by region. For instance beef and eggs in Japan have substantially more MK-4 than in the United States. This depends on things like what an animal eats (3). If animal feed contains menadione, they will produce more MK-4. Organ meats like the liver, pancreas, kidneys and brain contain more MK-4 than other parts of the animal (3). 

Brie, Cheddar, parmesan, cream cheese, ice cream and Greek yogurt contain smaller amounts of MK-4 (4).

There is no RDA specifically for MK4, but the research that shows benefits for bone health uses at least 1.5 milligrams per day. This is much higher than the micrograms that you typically get from foods.

Does this mean you need to take an MK4 supplement? Not necessarily, since your body can convert other forms to MK4. You can read more about this at The Vitamin K Roadmap.

Best Food Sources of MK-7

Bacteria produce vitamin MK7. It is found in relatively small amounts in fermented foods such as cheese and sauerkraut, and in much larger amounts in a fermented soybean dish called natto.

Here are some ways to get MK7 from food:

You can see that natto is hands down the best way to get MK7.

The amount of MK7 in cheese is extremely variable. Some studies have found Swiss Gruyere and Emmental, French Comte and Norwegian Jarlsberg to be the best sources (5).  

In a study published in Nutrients in 2018, Camembert, Gorgonzola and Munster had the most MK7. Cheddar, Roquefort, Stilton, Feta, Raclette, Gamalost, Gouda and Norvegia had lesser amounts of MK7 (5).

Longer fermentation and higher fat content tend to increase the amount of MK7 and other menaquinones. 

Other Long Chain Menaquinones

Although MK4 and MK7 get the most airtime when it comes to bone health, there are many other forms of menaquinone present in fermented food. 

For instance, fermented dairy contains more MK8 and 9 than any other menaquinone (6). MK9 is a major menaquinone in some fermented cheeses, found in much higher amounts than MK7 (7).  

Since they can all be converted to MK4, eating foods that are high in long chain menaquinones can be a good strategy to increase your MK4 levels (8).  

The amount of menaquinone can vary depending on where the food is produced, how an animal is fed, how long a food is fermented, and what type of bacteria is used in fermentation. Fat content also plays a big role in the amount and absorbability of menaquinone (9).   

K2 in US Dairy Products

A 2017 study analyzed dairy products obtained from the USDA Nutrient Data Laboratory and retail stores in the United States (10). They looked at MK content of milk, yogurt, Greek yogurt, kefir, cream, processed cheese, fresh cheese, blue cheese, soft and semi-soft cheese, and hard cheese. 

The foods they analyzed had appreciable amounts of menaquinone. Ninety percent of these were in the form of MK-9, MK-10 and MK-11. There were also modest amounts of MK-4, MK-7, MK-8, and MK-12.

Soft cheese had the highest level of menaquinone, followed by blue cheese, semi-soft cheese, and hard cheese. Unfermented, processed cheese was low in menaquinone.

Milk followed the same pattern, with high amounts of MK-9, MK-10 and MK-11, and lesser amounts of MK-4. Full fat milk had the highest levels of menaquinone. Fat free milk was low in K2 or had none at all. 

Full fat yogurt had higher levels of menaquinones than low fat. Some fat free versions contained no menaquinone at all. Both regular and Greek yogurt contained MK-9, MK-10 and MK-11, with smaller amounts of MK-4.

Full fat cottage cheese was high in MK-8, MK-9 and MK-11. The fat free version of cottage cheese had substantially less menaquinone.

Takeaway: Dairy products with a higher fat content contain more long chain forms of menaquinone, which are different forms of K2. Since these forms of menaquinone can be converted to MK4 in your tissues, they are likely just as beneficial for bone health.

Why Choose Food Instead of a Supplement?

When you take a vitamin K supplement, all you are getting is vitamin K. When you eat a food that contains vitamin K you are getting all the other nutrients in the package.

Leafy greens provide not only vitamin K, but also vitamin C, vitamin A, iron, copper, calcium, magnesium, manganese, potassium, selenium, strontium, zinc, and even some protein.

Fermented dairy gives you a great source of calcium, protein, magnesium, phosphorus, potassium and zinc along with your vitamin K.

Many people reach for an MK7 supplement instead of eating natto. However, by doing this they are missing out on soluble fiber, protein, soy isoflavones, natural probiotics, and a long list of other vitamins and minerals. 

What is the best way to eat vitamin K-rich food?

You always want to eat vitamin K-rich food with a meal that contains some fat. Fat causes your gut to release bile acids. Vitamin K is absorbed in tiny fat droplets that form with the help of those bile acids (11).   

You might be wondering exactly how much fat you need to absorb fat soluble vitamins. A meal with 10 grams of fat gets a very efficient response from the gallbladder (12). One tablespoon of oil has about 14 grams of fat, which is more than enough to help you absorb that vitamin K.

Wrapping It Up

There are 3 forms of vitamin K: phylloquinone (K1), menaquinone (K2) and menadione (K3). Menaquinone has at least 10 different variations in its structure. Research shows that K1, MK4 and MK7 all have benefits for bone health.

Vitamin K1 is made in plants, and you can get it by eating plants. Leafy green vegetables are an especially good source of vitamin K1.

MK4 is produced in human and animal tissues. You can get this vitamin by eating animal products like meat, milk and eggs.

The menaquinones with longer chains than MK4 (MK5 and up) are produced by bacteria. You can get them from fermented vegetables and dairy products like cheese, yogurt and kefir. The best food source of MK7 that we know of so far is natto. All the menaquinones can be converted to MK4 in your tissues.

How do you get your vitamin K? Let me know in the comments.