Vitamin K2 (menaquione) is an important nutrient for tooth health (plus overall health).
Vitamin K2 improves tooth and bone mineralization while simultaneously decalcifying soft tissues. The result is that K2 strengthens teeth and bones while also improving the health of organs and blood vessels.
But what are the best vitamin k2 food sources?
The answer is: it depends.
Although many websites claim that such-and-such food is an excellent vitamin K2 food source, they rarely tell you the whole story.
I’m going to try to keep this as simple as possible. But know in advance that this is not as simple as “eat foods x, y, and z and you’ll have all your vitamin K2 needs covered”.
It’s a little more nuanced.
There Are Different Types of Vitamin K2
Vitamin K2 is a name given to a class of nutrients called menaquinones.
Not all menaquinones behave identically. In other words, not all vitamin K2 does the same thing.
There are currently ten different menaquinones known: menaquinone-4 (mk-4), menaquinone-5 (mk-5), menaquinone-6 (mk-6), etc.
Of these the menaquinones that researchers have looked at in much detail are mk-4 and mk-7. It is possible that the other menaquinones are helpful for dental and bone health, but these are the two menaquinones with the most research behind them at this point.
Which is Better for Dental and Bone Health: MK-4 or MK-7?
Of the two menaquinones that have been studied the most, which is more effective in supporting dental and bone health?
I don’t know the answer to that question, and I don’t believe anybody else does either. But I can tell you that substantial evidence suggests that at the very least mk-4 (menaquinone-4, also known as menatetranone) is effective in improving dental health (preventing and reversing tooth decay).
And it is worth noting that long before researchers identified the group of chemicals they call vitamin K2, Weston A Price found experimentally that “high vitamin butter oil” contained a substance he called “activator X” that improved dental health.
“Activator X” is now known to be what researchers call mk-4.
High vitamin butter oil is made from butter produced from cows eating fresh, spring grass. Cows and other ruminants convert vitamin K1 from fresh grass into mk-4. Thus, spring butter while cows are eating fresh, green grass is substantially higher in mk-4 compared with any other butter.
The mk-4 form of vitamin K2 is the form produced by animals. Animals seem to convert many other forms of vitamin K (both K1 and K2) to mk-4.
Therefore, unfermented animal foods such as meat and dairy, are among the richest sources of mk-4.
This does not mean that other forms of vitamin K2 are not potentially useful for dental and bone health. But it makes sense to me to emphasize food sources of mk-4.
What Are the Best Vitamin K2 Food Sources in the MK-4 Form?
The richest vitamin k2 food sources of mk-4 are foods that most of us don’t eat a lot of:
- goose liver
Yes, that’s right. Testes. Rocky mountain oysters, for example.
As such, I suspect that we may be able to generalize that mk-4 is highest in these organs in most animals.
Goose liver has the highest concentration of mk-4 of any type of liver tested, and therefore is one of the best vitamin k2 food sources.
So it is likely (though unproven at this time) that you can obtain your mk-4 by regularly eating these foods. Of which, kidneys and goose liver are probably the easiest to find.
If you can’t find or don’t want to eat these foods, your next best bets for vitamin k2 food sources are: 
- chicken (dark meat only)
- goose (leg)
- egg yolk
When it comes to butter, egg yolk, and cheese, the levels of mk-4 are almost certainly going to be *much* higher when the foods come from animals eating fresh, green plants.
Of these, dark meat poultry seems to be your best bet for vitamin K2 food sources.
How much of these foods do you need to eat to get enough mk-4 daily?
First, it depends on what “enough” is. There is not enough information presently to know what enough means.
Japanese research has shown miraculous benefits for some people using 45 mg of mk-4 daily. But understand that is way more than you could conceivably obtain from food on a daily basis. And that research didn’t test to find out if smaller amounts could confer the same benefits.
According to some researchers such as Chris Masterjohn, 200 mcg (mcg = microgram, so 200 mcg is 0.2 mg) is a reasonable goal for daily intake for combined menaquinone.
Here’s a just one example of what you’d need to eat to achieve that goal:
- 5 egg yolks = 32 mcg mk-4
- 1/2 cup duck fat = 100+ mcg mk-4
- 1/4 lb goose leg = 31 mcg mk-4
- 1/4 lb chicken thigh = 27 mcg mk-4
That’s about 200 mcg of mk-4 all together.
Masterjohn isn’t suggesting that you need to consume all vitamin K2 in the mk-4 form. There are other foods in his database that contain substantial amounts of non-mk-4 vitamin K2. But for the reasons I’ve given in this article, I’d emphasize mk-4, aiming to eat as much of my vitamin K2 in the mk-4 form as is reasonable.
What about Supplements?
Supplemental mk-4 may be a reasonable alternative for those who are unable or unwilling to consume enough mk-4 from vitamin k2 food sources.
I cannot guarantee that supplemental mk-4 is safe, but the research has shown it to be remarkably free of side effects, even in very large amounts.
The supplemental mk-4 products I’ve personally used are from Thorne and AOR. I also see that Relentless Improvement has an mk-4 supplement that looks good in theory.
If you are trying a supplemental mk-4 product, I strongly recommend that you take it with food that contains fat such as butter, olive oil, or coconut oil. Vitamin K2 is fat-soluble, and you will likely absorb it much better when taken with dietary fat.
Here are links to the mk-4 products on Amazon: