Vitamin K2 Benefits, Food Sources, and More!

What do a hearty breakfast, nature, and vitamin K2 have in common?

They all tend to be underappreciated!

Breakfast is all too easy to skip or substitute for coffee. The beauty of our planet is often taken for granted. And as for vitamin K2… well, it’s known as the “missing nutrient” after all!

Oftentimes, Vitamin K2 is absent in the Standard American Diet, but that could be a huge oversight. See, vitamin K2 benefits your health at all stages of your life. It provides an essential service to your bones, as well as a host of other health benefits that may surprise you.

We’ll cover the vitamin K2 benefits in just a moment, but first, let’s look at vitamin K in a more general sense.


What is Vitamin K?

Danish scientist Henrick Carl Peter Dam discovered Vitamin K during his work in the late 1920’s and early 30’s. Dam was researching sterol metabolism in chicks, which involved restricting their diets. But he found certain dietary restrictions produced cases of internal bleeding.

Dam tried several already established vitamins like A, C, D, and E to prevent the internal bleeding with little success. But he did find feeding the chicks cereals and seeds had protective effects.

So there was something in the cereals and seeds that stopped the internal bleeding. But what was it?

Well, it was a newly discovered vitamin! Dam called his discovery “Koagulations vitamin”– that’s the Scandinavian spelling of coagulations– because the chick’s blood couldn’t coagulate (clot) without it. Afterwards, Koagulations vitamin was abbreviated to vitamin K.

Impress your friends factoid: Dam was awarded The 1943 Nobel Prize in Physiology or Medicine for discovering vitamin K! (He shared the award with Edward Adelbert Doisy who discovered the chemical nature of vitamin K).

“But where does the 2 in vitamin K2 come in?” you may be wondering. Well, Henrick Dam’s discovery is just half of the story. See, there are several forms of vitamin K so “vitamin K” is actually the umbrella term for a whole group of fat-soluble vitamins. The main forms are:

  1. Vitamin K1 (also known as phylloquinone)
  2. Vitamin K2 (also known as menaquinone)

We’ll cover what each form does in the next section. Plus, we’ll explain why vitamin K2 is crucial for healthy bones!


Vitamin K1 and Vitamin K2 – How Do They Work?

There are two main forms of vitamin K. Both are extremely important for your health, but in different ways.

 

Vitamin K1 (phylloquinone)

This is the form of vitamin K Henrick Dam discovered. The scientific name for Vitamin K1 is phylloquinone because it’s made by plants. Phyllo is Greek for leaf, and the quinone part of phylloquinone refers to its chemical structure.

You can find vitamin K1 in plant-based foods– if you recall, Henrick Dam fed his chicks cereals and seeds. Although K1 is found in highest amounts in leafy greens like kale and collard greens.

When it comes to your body, Vitamin K1 is a co-factor (a substance that’s essential for the activity of an enzyme) for the enzymes involved in clotting your blood. If you didn’t have any vitamin K1, even a tiny nick while cutting your veggies would cause you to bleed to death!

If you have any vitamin K1 left after fulfilling your blood clotting needs, your body can use it to lower inflammation. It does this by reducing the production of signaling agents your body produces called cytokines. The pro-inflammatory cytokines tell your inflammation-producing machinery to turn on and ramp up. And that’s bad news for your bones because chronic low-grade inflammation causes bone loss!

 

Vitamin K2 (menaquinone)

Vitamin K2 is the form of vitamin K that’s essential for healthy bones. There are a number of dietary sources of vitamin K2 including eggs, meat, and various cheeses. But very few provide you with the most desirable form of vitamin K2 (more on that in just a moment.)

So how does vitamin K2 benefit your bones? Well, you already know calcium is the cornerstone of bone health. But vitamin K2 activates the two proteins that regulate where the calcium you consume goes in your body:

  1. Osteocalcin: Directs the calcium you consume to where it’s needed… your bones!
  2. Matrix Gla protein: Keeps calcium out of the places you don’t want it– your blood vessels, kidneys, brain, and soft tissues.

Think of vitamin K2 as your body’s very own set of traffic signs, specifically designed for calcium.

So you could consume more than enough calcium, but without vitamin K2, you’ll still have weak bones because they’re not receiving any of that calcium. Calcium and vitamin K2 work as a team to keep your bones strong and healthy. And in fact, there’s a third member of the team– vitamin D. See, vitamin D helps your body absorb the calcium you consume in the first place.

If you want to read a little more about the teamwork of calcium, vitamin D, and vitamin K2, check out our “Calcium and Osteoporosis” page.

Types of Vitamin K2

So, we’ve established there are two main forms of vitamin K: vitamin K1 and vitamin K2. And vitamin K2 is the form you need for strong bones. But to make matters a touch more complex, there are several forms of vitamin K2 too! Don’t worry though; we’ll explain it all for you.

Recent research has focused on two forms of vitamin K2 in particular:

MK-4

You absorb all forms of vitamin K – that’s K1 and all the different forms of K2 – in your small intestine before they’re sent to your liver. But here’s where the script changes depending on the form.

See, MK-4 is structurally similar to vitamin K1 (as you can see in the diagrams above). So your body uses them in a similar way. That means your body will first use MK-4 to activate the blood clotting proteins in your liver (remember, blood clotting is the primary job of vitamin K1).

If there’s any left over, it’s packaged up inside triglycerides (little packages of fat bound to a glycerol sugar molecule) and sent into your bloodstream. This leftover MK-4 will perform the bone-supporting tasks we outlined in the last section, but there’s an important thing to note…

…MK-4 doesn’t stick around for long! In fact, it’s cleared from your bloodstream in 6-8 hours– this is the “half-life” of MK-4.

MK-7

As you can see from the diagrams above, vitamin MK-7 is structurally different from vitamins K1 and MK-4. That means your body uses it differently.

You still absorb Vitamin MK-7 in your small intestine before it’s sent to your liver. But it won’t be used to activate the blood clotting proteins (unless you’re seriously lacking vitamin K1 and MK-4). Instead, MK-7 is packaged up in LDL cholesterol and sent into your bloodstream. Then it activates the proteins that direct calcium to your bones and keep it out of your organs, arteries, and soft tissues.

And get this; LDL cholesterol circulates around your body for several days. MK-7 actually stays in your body for up to 4 days! (Remember, MK-4 only sticks around for 6-8 hours). What’s more, the fact that MK-7 has a longer half-life means you can build up a steady level when you consume it regularly.

It’s like having a special vitamin K2 bank account. You can withdraw from it each day to continuously activate the osteocalcin and matrix Gla proteins to steer the calcium you consume in the right direction… your bones!

MK-7’s much longer availability is the reason a small dose – as little as 90 micrograms per day – may be all you need to optimize your body’s ability to activate osteocalcin and matrix Gla protein.

In contrast, you’d need to take a very large dose of MK-4 several times a day to have any available to activate osteocalcin and matrix Gla protein. Now, research shows MK-4 does benefit people with osteoporosis and osteopenia. But only in doses of 45 milligrams a day (15 milligrams three times a day.)



Vitamin K2 Health Benefits

Research on the health benefits of vitamin K2 is still in its early stages, but studies have already uncovered a wide range of benefits. You can see the top 7 health benefits of vitamin K2 below:

Please note: The benefits below are true of all forms of vitamin K2. But remember, the MK-7 form has a much longer half-life and isn’t used for blood clotting purposes first, so you have a better chance of reaping the benefits with MK-7.

Helps Prevent Osteoporosis

As we covered in the “Vitamin K1 and Vitamin K2 – How Do They Work?” section, vitamin K2 activates a special protein– osteocalcin –that directs calcium to your bones. And as you know, the more calcium your bones have, the stronger and denser they’ll be.

The research: Researchers behind a study published in the journal “Osteoporosis International” wanted to investigate whether vitamin K2 supplements could decrease the age-related decline in bone mineral density (BMD) and bone strength. They gave 244 postmenopausal women either a 180 microgram capsule of MK-7 or a placebo once a day for three years.

The results? The women taking MK-7 significantly decreased the age-related decline in BMD at their lumbar spine and femoral neck sites (but the total hip was not significantly affected.) Their bone strength was also favorably affected by MK-7.

 Lowers Risk of Heart Disease

The other special protein vitamin K2 activates is matrix Gla protein. Matrix Gla keeps calcium from accumulating in places you don’t want it. And one such place is your arteries and your heart!

If calcium does accumulate in your arteries and heart, you’ll be at greater risk of heart disease. So, on the flip side of the coin, getting enough vitamin K2 can reduce your risk of heart disease – because it directs the calcium to your bones and out of places you don’t want it!

The research: The Rotterdam study was a population-based study to assess the occurrence of diseases of the elderly and to clarify their cause. When it came to heart disease, the study revealed that men and women aged 55 and over who consumed over 200 micrograms of vitamin K2 a day had up to 57% lower risk of dying from heart disease than those who consumed under 200 micrograms.

What’s more, another study revealed the risk of heart disease drops by 9% for every 10 milligrams of vitamin K2 you take a day (specifically the longer chain MK-7, MK-8, and MK-9 forms.)

Keeps Your Teeth Strong

The osteocalcin and matrix Gla proteins are the gift that keep on giving! As well as providing you with the bone benefits we’ve discussed, they help keep your teeth strong and decay-free too!

The process is actually the same for teeth as it is for bone. The matrix Gla protein prevents calcium from accumulating in the places you don’t want it to, and the osteocalcin protein directs – a small amount – of calcium to your teeth! What’s more, these wonder proteins play a role in mineralizing your teeth and defending them from bacteria which can cause decay.

If you’d like to read a little more about vitamin K2 and teeth, best-selling author and dentist, Dr Steven Lin, has a detailed post on the topic.

Lowers Inflammation Rates

This is more good news for your bones. See, chronic inflammation activates your osteoclast (bone resorbing) cells to break down and remove bone. But research shows regular intakes of K2 helps reduce inflammation by suppressing inflammatory cytokines (protein signals in cells)!

Fights Autoimmune Conditions

Vitamin K2 can have a positive effect on certain autoimmune conditions. For example, research shows people with rheumatoid arthritis have a lower chance of developing other autoimmune conditions if they take vitamin K2.

 

Helps Prevent Cancer

Some studies show vitamin K2 may have anticarcinogenic powers too. Particularly when it comes to prostate cancer. A study on the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg) evaluated the association between dietary intake of vitamin K1 and vitamin K2 and total and advanced prostate cancer.

The study found vitamin K1 intake had little to no association with prostate cancer. But vitamin K2 intake was linked with a 35% lower chance of total prostate cancer, and a 43% lower chance of advanced prostate cancer. The authors noted further research on the association between vitamin K2 and prostate cancer is needed. But these results are a promising start!

What’s more, other research shows vitamin K2 may help kill lung cancer cells too.

Longevity

Yes, research shows vitamin K2 could even be linked with living longer!

A prospective cohort (a type of study that follows a certain group over a long period of time) was conducted in 7,216 Mediterranean men and women. Their nutrient intakes were evaluated using a 137-item food frequency questionnaire, and their dietary vitamin K (both vitamin K1 and vitamin K2) intake was calculated using the USDA food composition database.

Long-term results showed individuals who increased their intake of vitamin K1 or vitamin K2 had a lower risk of cancer and all-cause mortality (death) than individuals who decreased their intake or didn’t change it at all!


The Best Vitamin K2 Food Sources

Remember when we said vitamin K2 is known as the “missing nutrient”? Well, here’s the reason… it’s very difficult to get vitamin K2 into your diet. (That is, enough to provide you with the health benefits we’ve mentioned on this page anyway).

Now, your body can actually convert vitamin K1 into vitamin K2. But there’s a catch; the conversion will only happen if there’s enough vitamin K1 left after it’s been used for its blood clotting and other jobs. If you eat a lot of leafy greens like kale and collard greens, you may consume enough vitamin K1 to have some leftover to convert into vitamin K2. But it would have to be a lot of leafy greens. And for most people, it’s an unrealistic amount.

So which foods are the best source of vitamin K2? And which provide the more desirable MK-7 form of vitamin K2?

Our resident Bone Health Expert, Lara Pizzorno, sheds some light on the best food sources of vitamin K2 in the video below:

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So, as Lara explained in the video above, there are several sources of the MK-4 form of vitamin K2. But you’d have to eat ridiculous amounts of the food to get enough vitamin K2 to reap the bone and other health benefits.

As for the more desirable MK-7 form of vitamin K2, there’s only one known food source– natto. Natto is a Japanese food made from fermented soybeans. It contains a lot of vitamin K2, but it’s hard to come by in Western supermarkets, and it’s an acquired taste.


Richest Food Sources of Vitamin K2

Food (Typical serving size) Amount of K2 (micrograms) Primary type of K2
Natto (1.4 oz) 380 MK-7
French Brie-style cheese (1 oz) 21 MK-9, MK-10
Norwegian Jarlsberg cheese (1 oz) 6 – 19.5 MK-9
Emmentaler (1 oz) 6 – 19.5 MK-9
Cheddar cheese (1 oz) 2.9 MK-9
Egg yolks (2 = 1 oz) Netherlands 9 MK-4
Egg yolk (2 = 1 oz) U.S. 4.4 MK-4
Eggs, hard-boiled, 3 7 MK-4
Eggs, pan-fried, 3 9 MK-4
Chicken liver pan-fried (4 oz) 14.4 MK-4
Chicken breast (4 oz) 10 MK-4
Beef, ground, medium fat (4 oz) 9.25 MK-4
Beef, ground, low fat (4 oz) 7 MK-4
Meat franks (4 oz) 11.2 MK-4
Sauerkraut (3.5 oz) 4.8 Mixed
Salmon (3 oz) .57 MK-9
Whole milk (8 oz) 2.2 MK-4
Skim milk 0 none

How Much Vitamin K Do You Need?

The recommended dietary allowance (RDA) for vitamin K2 hasn’t been established yet. Although research shows 360 micrograms a day of the MK-7 form is certainly effective, and as little as 90 micrograms could be enough to be beneficial for people with osteopenia and osteoporosis.

As for vitamin K1, between 90 -120 micrograms a day is the suggested intake. (You can see the recommended amount for men and women of each age group below).

Adequate Intake (AI) for Vitamin K

Life Stage Age Females
(mcg/day)
Males
(mcg/day)
Infants 0-6 months 2 2
Infants 7-12 months 2.5 2.5
Children 1-3 yrs 30 30
Children 4-8 yrs 55 55
Children 9-13 yrs 60 60
Adolescents 14-18 yrs 75 75
Adults 19+ yrs 90 120
Pregnancy 18+ yrs 75
Pregnancy 19+ yrs 90
Breastfeeding 18+ yrs 75  –
Breastfeeding 19+ yrs 90

The Easy Way To Get Vitamin K2 (and support your bones)

Getting enough vitamin K2– especially in the MK-7 form which sticks around long enough to benefit your bones and the rest of your body– from your diet alone is a real challenge. Your only option is trying to find somewhere that sells natto, and hoping you can stomach the taste (and smell.)

But there is another way

AlgaeCal Plus is a calcium supplement that contains 100 micrograms of vitamin K2 a day. And it’s the desirable MK-7 form too! What’s more, AlgaeCal Plus contains 100% natural ingredients.

It’s the most convenient, effective way to get enough vitamin K2 to benefit your bones.

Click the banner below to discover more about AlgaeCal Plus:


Vitamin K2 Safety Concerns

Vitamin K2 on its own is completely safe.

But there are several medications– like blood thinners for example– which can interfere with vitamin K2, and this can be dangerous. If you’re already taking medications, the best course of action is to ask your healthcare provider if taking vitamin K2 along with it is safe.


Takeaways

Vitamin K2 often flies under the radar in the Western world… but that’s a huge oversight. Especially for people concerned with their bone health.

Vitamin K2 activates proteins that keep the calcium you consume out of your organs, arteries, and soft tissue, and direct it to where you need it most– your bones! And remember, the long chain MK-7 form of vitamin K2 is the most desirable because it sticks around in your body long enough to provide you with those bone benefits, as well as a range of incredible benefits for the rest of your body.

But it’s very difficult getting enough vitamin K2 into your diet (especially the MK-7 form). The only real dietary source is the fermented soybean product, natto. And to say natto is an acquired taste is an understatement…

That’s why supplementation is likely your best, most convenient option. Especially if you choose AlgaeCal Plus. A daily serving contains 100 micrograms of vitamin K2 in its MK-7 form– an amount research shows may be of benefit to those with osteopenia and osteoporosis!

What’s more, AlgaeCal Plus contains all 13 essential minerals for supporting healthy bones.