It is best to take your K2 with your dinner that includes dietary fat or at bedtime, 8 to 12 hours after you take your

vitamin D3. This is why most people take their D3 with breakfast and K2 at dinner time. We suggest this since some

research shows that D3 is more effective if not taken at the same time as K2. Fat soluble vitamins compete for fat for

transport into the body, The Vitamin D wins and in doing so prevents the K2 from getting into the body. You must

always take your vitamin K supplement with fat since it is fat soluble and won't be absorbed without it. When taking

moderate to large doses of fat soluble vitamins there is reduced absorption of other fat soluble vitamins by estimated

10 to 50% due to competition. Absorption of vitamin K appears to be particularly reduced by other fat soluble vitamins,

while vitamin A absorption is least affected and may actually be better absorbed when taken with vitamin E. Taking

vitamins D, E, or K several hours before or after other fat soluble vitamins would seem to maximize their absorption.

That said many have been successful at safely raising their vitamin D levels while taking their K2 at the same time as

D3 or not taking K2 at all. But we like to think that if you are taking what you believe is a high dose of D3 that K2

eliminates any doubt of vitamin D toxicity. Caution! If you’re taking blood thinning medicines, such as Warfarin or

Coumadin, don’t take vitamin K supplements that include K1. This is because it may affect how well your blood clots.

Be very careful since many products labeled K2 can also include K1. If you are taking Coumadin you may want to look

at new research that shows that you should be taking about 45 mcg of the MK-4 version of K2, but please discuss this

with your cardiologist before going this alone. Soy is also not recommended for those who have been diagnosed or

suspect that they have thyroid disorders. You might want to use a non-soy based K2 product. Here's one we have used 

in the past from Sports Research on Amazon.

K2 is preferentially used by other tissues to deposit calcium and phosphorous in appropriate locations, such as in the

bones and teeth, and prevent it from depositing in locations where it does not belong. Such as the soft tissues, arterial

walls, joints and organs. It a nutshell, K2 is keeping the calcium going where it needs to go. Some people complain of

slight heart palpitations when adding K2 to their daily protocol. If you are one of those people make sure you shift to a K2

[here is the Relentless brand on Amazon] that contains only MK4 as it does not cause heart palpitations and is

more tolerable.

But there is even more good news when it comes to the MK-4 version of vitamin K2. Researcher Thomas Golda tells

us "Studies are now underway combining MK4 and D3 for the treatment of many cancers. MK4 "alone" has come under

the umbrella of the FDA where they admit that it has the potential to treat some of these conditions. MK-4 regulates

gene expression in specific ways that no other form of vitamin K does. In a wide variety of cells, it turns on the genes

that keep cells healthy and turns off the genes that make cells become cancerous. Thus, MK-4 plays an exclusive role

in cancer protection and overall health. This special role of MK-4 probably explains why all animals break down other

forms of vitamin K and convert them to MK-4. By contrast, no animal synthesizes any other form of vitamin K. As a side

note on MK-4, one does not need to take high amounts of MK-4 for the purposes of preventing bone loss and bringing

calcium from the blood and to the bones. Recent studies have shown just 1-2 mg of MK-4 does remarkably well. The

reason why one may take higher amounts, like in the 15 - 45mg range, is because those higher amounts have been

shown to prevent cancer, prevent liver disease, prevent diabetes and a whole host of other benefits. But if one's purpose

is just preventing bone loss, small amounts do just fine".

It's true that vitamin K research is still in it's infancy. Some have stated that K2 is not even available in food so there is

no reason to take it. But that's just not true. Here's how Dr. Cannell at the Vitamin D Council responded to the question:

"As early as 1994, researchers had discovered that K1 converted into K2 in the body. In 1998, researchers confirmed

that K1 is metabolized into K2 and that metabolism had nothing to do with intestinal bacteria. Sterile mice metabolized

ingested K1 into K2. In 2006, researchers confirmed this conversion takes place in humans. There appears to be two

sites of conversion of K1 to K2, one in the intestine and another in peripheral tissues. Recently, the mechanism by

which the body turns vitamin K1 into vitamin K2 was clarified. It occurs through an intermediary molecule, vitamin K3,

which is made in the intestine from vitamin K1".

​You don’t have to worry about overdosing on mk-4. 15,000 mcg a day has become a very common dose. And some

researchers have been taking this dose for years. And our move toward mk-4 over mk-7 goes way beyond being a D3


How Safe is the mk-4 Version of Vitamin K2?

In cancer studies in the 1990s, they gave Vitamin K3 (which is not sold as an over the counter supplement and converts

to MK-4 in the liver] to patients intravenously in doses of 2.5 “grams” a day. Not milligrams but grams. 2.5 grams = 2500

milligrams = 2,500,000 mcg of Vitamin K2 after conversion. 15,000 mcg in the doses we are suggesting are nothing. It

really just represents a good maintenance dose.

The Superiority of MK-4 over MK-7

Only MK-4 is the only K2 in the brain. MK-7 is absent in the brain.
MK-4 manages inflammation in the brain. MK-7 does not.
MK-4 has the highest concentration in human tissues. MK-9, MK-8 and MK-7 in that order, are in tissues. So you could say that MK-7          is the 4th most important K2.
MK-4 crosses the placenta. For pregnant women this is important for the health of the fetus. MK-7 does not pass to the fetus.
Human breast milk contains MK-4. It does not contain MK-7.
MK-4 protects against over a dozen different cancers. MK-7 has no anti-cancer benefit.
MK-4 prevents calcium buildup in the arteries "better" than MK-7.
MK-4 protects against cirrhosis of the liver. MK-7 does not.
MK-4 protects against Alzheimer's disease. MK-7 does not.
MK-4 protects against Parkinson’s disease. MK-7 does not.
Promotes healthy platelet, white and red blood cell production in people with leukemias. MK-7 does not

The "trans" form of MK-7 is the only beneficial isomer.
In "food," such as Natto, MK-7 is 100% in the trans form.
In MK-7 "supplements," the majority of the supplement are "not" in the pure trans form.
The trans form of MK-7 is the only active form of menaquinone able to act as a cofactor for carboxylation.
The majority of MK-7 supplements also have the "CIS" form.
The CIS form is 100% useless and does not act as a cofactor for carboxylation.
In the majority of MK-7 tested, despite claims of being mostly in the trans form, the independent testing showed they were not. They were in the CIS form.
The CIS form has an "unknown toxicity profile." (is it any wonder why so many have side effects?)
Some manufacturers are dishonest in their "trans" claims.
The CIS form can be there "from the start" in MK-7 supplements.
The CIS form can also "convert" from the "trans" form over time and by "oxidation." Which means, over time, MK-7 supplements become more "CIS like."
Most manufacturers of MK-7 use "cheap processing" to make this, and that is why there is a large issue with "impurity" with the supplements.
As this does not impact MK-7 "from food." It is 100% in the trans form. You will not have the issue with potential toxicity with food, BUT if you are sensitive to soy, you can still have side effects from food in the trans form, as "soy" is a stimulant.
When it comes to "MK-4" supplements, the supplement form is "bio-identical" to what is in food. There is no issues in terms of impurity or toxicity or getting "something different" in the supplement form compared to what is in food.
In Japan, where they are one of the largest consumers of "natto," they only recommend "MK-4" as a supplement for the treatment of osteoporosis, and have been doing so since 1995.

Our Most Common Vitamin K2 Questions

What is considered a good dose of Vitamin K2?

​If you are taking the mk-7 form of vitamin K2 it is very important to be careful with your dose. 90-100 mcg is considered 

the normal dose for an adult. Some groups have suggested as high as 180-190 mcg would be safe. This is not true with 

the mk-4 version of K2. 500-600 mcg would serve the purpose of our vitamin D protocol but a therapeutic dose of 15,000

mcg is common and safe. In fact mk-4 has proven to be safe in almost any dose.

I Have Heard That Vitamin K2 Can Reduce Arterial Calcification, Is This True?

​In 2004 the Rotterdam study of 4807 people, showed that just 0.032 mg of Vitamin K2, reduced arterial calcification by

50%, cardiovascular risk by 50% and all-cause mortality by 25%. If one thinks for a second the consequences of those

findings. 0.032 mg of K2 is a "tiny" amount. And that tiny amount reduced cardiovascular risk (including heart attacks)

by 50%. There is no drug, no supplement, no surgical procedure, nothing that comes close to doing that.

​Why Are You Recommending a Tablet Form of MK-4 Over a Liquid Form?

​There are a couple of reasons. One...You get more for your money with the Relentless Brand we are recommending compared to the popular liquid Thorne Brand. Two...the Thorne MK-4 is good, but because it is liquid they add medium chain triglycerides and in some people that does have side effects, including palpitations. Also, Thorne MK-4 has “mixed tocopherols” and this also can be derived from Soy. Many people experience palpitations with MK-7 for these same reasons.

​Can the mk-7 form of Vitamin K2 influence female hormones? My bloodwork showed my prolactin and some other

hormone is higher than it should be, causing my menstruation to be 15 days late. I’m never late. 

​The answer is "yes" and "no." In itself, mk-7 will not impact your female hormones and monthly cycle. However, Soy can.

Soy is the main ingredient in mk-7 supplements. Soy and Natto contain high levels of phytoestrogens that mimic the body's

natural estrogen hormones. It also impacts uterine health and the reproductive cycle in a bad way. Soy also inhibits thyroid

function due to the high levels of goitrogens which can be antagonistic to the thyroid hormone. Some mk-7 brands have

worse Soy than others. So, the best thing to do is to just stick with mk-4. MK-4 has nothing to do with soy, and does not

have the legion of side effects as can be associated with soy-based mk-7 supplements.

Since I have been taking the NOW brand of Vitamin K there has been changes in my menstrual cycle. I’m seeing a lot more blood clots. Is this something I should be concerned about?

​Stick to brands like Relentless Improvement that have MK-4, not the specific brand you are taking. The NOW brand in general, is a very good high quality company for supplements, but on any supplement you are taking, you have to look at "what additional" things are in it. The NOW brand of MK-4 also includes  Alfalfa powder. Alfalfa powder has high amounts of Vitamin K of all types, and can be an issue with blood clotting. Just use MK-4 alone with no additional herbs or plants added to it. Go here for more details on the Relentless brand of mk-4.


It has become obvious that vitamin K2 is important part of any Vitamin D Protocol. This becomes even more critical when taking higher daily doses [more than 10,000 I.U.s daily] of vitamin D3. You should at least take K2 several times a week, but preferably once a day. How much does depend on how much you get in your diet. A vitamin K rich diet includes lots of cabbage, kale, spinach, Swiss Chard, green leafy vegetables, broccoli, cauliflower, brussels sprouts, wheat bran and sauerkraut. As well as a very small amount of grass fed meat and dairy products, which should only be eaten in small amounts.

We are now suggesting that you try to include the MK-4 [this is the form made naturally by our bodies] version of K2 rather than the widely distributed mk-7 version if you can. Vitamin K research in the U.S. is in its infancy but researchers in Japan have taken the lead for decades proving the benefits of mk-4 for many uses besides our focus here with our Vitamin D Protocol.

Daily doses of 500-600 mcg found in many versions of K2 will serve our purpose to distribute calcium to our bones and teeth instead of major organs etc. If you are looking for a more therapeutic dose to address some of the issues we will talk about here we are using this product from Relentless in 15,000 mcg doses.

 We've done the research.....Here is our Vitamin D Protocol