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Is K1 essentially just as good as K2?

Commented on March 18, 2014
Created March 15, 2014 at 3:01 AM

According to the below except from Wikipedia (with appropriate citations) k2 is converted from k1 in mammals regardless of gut bacteria. If this is true then is K1 just as good as K2?

The MK-4 form of vitamin K2 is produced via conversion of vitamin K1 in the testes, pancreas, and arterial walls.[4] While major questions still surround the biochemical pathway for the transformation of vitamin K1 to MK-4, the conversion is not dependent on gut bacteria, as it occurs in germ-free rats[5][6] and in parenterally-administered K1 in rats.[7][8] In fact, tissues that accumulate high amounts of MK-4 have a remarkable capacity to convert up to 90% of the available K1 into MK-4.[9][10] There is evidence that the conversion proceeds by removal of the phytyl tail of K1 to produce menadione as an intermediate, which is then condensed with an activated geranylgeranyl moiety (see also prenylation) to produce vitamin K2 in the MK-4 (menatetrione) form.[11]

--Source--http://en.wikipedia.org/wiki/Vitamin_K#Conversion_of_vitamin_K1_to_vitamin_K2_in_animals

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 18, 2014
at 12:18 PM

It's alright, http://www.fda.gov.tw/upload/189/Content/2014012910261378895.pdf .

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 17, 2014
at 09:08 PM

One Caveat, is that you would still have to absorb the vitamin k1 into your bloodstream to begin with. And the research I'm looking at is showing that supplemental vitamin k1 has the highest absorption, followed by (gvien leafy green vegetable) cooked in butter (with less than 20% of the k1 making it into the blood), followed by given vegetable. http://advances.nutrition.org/content/3/2/182.full . Also k2-mk7 likely lasts longer in serum than k1. The studies I posted looked at k1->mk4 not k1->mk7 conversion. So don't stop eating your k2 rich foods just yet, lol.

96440612cf0fcf366bf5ad8f776fca84

(19463)

on March 17, 2014
at 09:07 PM

Hmm, looks like it's paywalled... oh well... would have been a fun read.

96440612cf0fcf366bf5ad8f776fca84

(19463)

on March 17, 2014
at 08:57 PM

I'm still unsure, but if it's true, and it's not severely rate limited, it would certainly make it a whole lot cheaper than supplementing with MK7; then again, liver and egg yolks aren't expensive anyway.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 17, 2014
at 04:09 PM

Yes, and I've previously posted a study showing this mechanism in humans in the comments on your answer... http://www.ncbi.nlm.nih.gov/pubmed/20953171 . It is independent of the gut or the bacteria in the gut..

96440612cf0fcf366bf5ad8f776fca84

(19463)

on March 17, 2014
at 03:31 PM

Do you have evidence that the same mechanism in rat guts applies to humans and that humans have the same bacteria as mice?

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 16, 2014
at 06:06 PM

When it comes to UBIAD1 it looks like we may be the same: http://www.ncbi.nlm.nih.gov/pubmed/20953171 .

96440612cf0fcf366bf5ad8f776fca84

(19463)

on March 16, 2014
at 01:22 PM

Are we mice? or men?

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 16, 2014
at 02:36 AM

Interestingly I stumbled across this, rejuvenation-science.com/n_vitamin-k2-artery.html . It's relevant and I'm really posting it just for reference. It shows that the dose may be the relevant factor when it comes to k1, though again, this is in rats.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 07:21 PM

When the old paleohacks switched over to the new paleohacks website a lot of profiles got fudged in the process. I made a meta post about this, if this is the same problem you are having then read the comments under my original post where a site admin supplies an email who you can contact to straighten this out. http://paleohacks.com/questions/494328/points-missing.html

0ba891d22837788c4d5ccf3f33f60329

(30)

on March 15, 2014
at 07:10 PM

This should be a viewable pdf of the full text btw: http://www.karger.com/Article/Pdf/75344

0ba891d22837788c4d5ccf3f33f60329

(30)

on March 15, 2014
at 07:08 PM

Actually, I am. Password issues, so I got a new profile.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 07:01 PM

Also, on a side note, you aren't the original mscott are you?

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 07:01 PM

I wish I could see the full text of the 14654717 pubmed article that you posted. I wonder what the dose and delivery method of k1 and mk-4 were and if there were any dose dependent effects or favorable but statistically non significant effects that were unreported in the abstract. Other than that, +1 for a Very solid answer.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 03:31 PM

Do you have evidence that the mechanism by which rats convert k1-k2 is exclusive to rats? It seems from the article posted by moors and from citation #11 from my post that this mechanism would at least be similar in humans and that there's no reason to think otherwise.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 02:22 PM

Here is a clinical study in mice showing supplemental k1 increases cell concentrations of k2: http://www.ncbi.nlm.nih.gov/pubmed/9446847 . This study also shows that this happens in mice with sterile guts (I think that's what its' saying but I'm no scientist).The only studies I'm aware of that show no benefit to k1 but benefit to k2 are epidemiological, and I'm not discrediting them just because they're epidemiological, but my critique would be that maybe even the highest percentiles of k1 consumption weren't high enough to be statistically significant. But I could be wrong, have studies?

32f5749fa6cf7adbeb0b0b031ba82b46

(41747)

on March 15, 2014
at 02:16 PM

Except that numerous studies show no benefit to K1 supplementation, but K2 supplementation does show effects. Which also does not support Mercola's claim that the half-life of MK-4 is a mere hour in the body. Maybe in serum, but it does not operate in serum, it does its work in cells.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 02:15 PM

Exactly, and it is beginning to look like bacterial conversion of k1->k2 may be largely meaningless compared to the conversions that are occuring outside of the gut at a cellular level, as touched on in the wikipedia page, the above ncbi article and moor's link.

32f5749fa6cf7adbeb0b0b031ba82b46

(41747)

on March 15, 2014
at 02:11 PM

Yes, but that doesn't mean that gut bacteria also don't do the conversion. The question is, where in the gut is K2 absorbed? If it's not the large intestine (few things are absorbed in the large intestine), then bacterial production of K2 is meaningless.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 01:24 PM

http://www.ncbi.nlm.nih.gov/pubmed/9446847

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 01:20 PM

Hey Raydawg, I used to think exactly what you're saying. However after reading through this wikipedia page and the appropriate citations I'm seeing that "In fact, tissues that accumulate high amounts of MK-4 have a remarkable capacity to convert up to 90% of the available K1 into MK-4.". This means that the authors of the Calcium Paradox and Mercola are right that the k2 produced by bacteria in the gut is not readily absorbed through the intestines, however, this also means that the k1 -> k2 conversion happens quite efficiently (90%) at a cellular level!

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 12:04 PM

Based on what I've read, the main reason k2 is advertised over k1 is because of a study that shows measurable reductions in bone fracture and CHD deaths in diets rich in k2 but not k1. These were epidemiological studies. I'm beginning to question these studies based on the premise that maybe even the highest percentage of k1 groups were not high enough to see a measurable difference. I agree that based on their explanations it doesn't seem like the conversion would make a difference, however,based on their explanations all the conversion happens in the gut, which is now shown to be false.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 12:00 PM

Oh, interesting link, +1!

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8 Answers

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0
0ba891d22837788c4d5ccf3f33f60329

on March 15, 2014
at 05:25 PM

First of all, K1 to K2 conversion in humans hasn't been studied, so anyone comparing it to beta-carotene or saying it's limited (or saying anything about the conversion) is just guessing.

If we go by clinical evidence, vitamin K1 supplementation seems to prevent fracture risk about as well as K2 (although this is only one study on older women): http://www.ncbi.nlm.nih.gov/pubmed/18922041

This study also found a reduction in cancer risk.

Vitamin K1 may also benefit insulin sensitivity in men just like K2: http://www.ncbi.nlm.nih.gov/pubmed/18697901

People talk about K2 and calcification. Personally, I suspect K1 will be less effective than K2 in this respect. There is observational evidence to support this, as you pointed out, but there is also some animal evidence:

http://www.ncbi.nlm.nih.gov/pubmed/14654717

"Despite their similar in vitro cofactor activity we show that MK-4 and not K1 inhibits warfarin-induced arterial calcification"

I personally think K2 will, possibly through greater delivery to peripheral, extrahepatic tissues, better activate the enzyme MGP and by doing so better oppose calcification of arteries and other stuff you don't want calcified. However there is no randomized, controlled evidence in humans supporting this so feel free to ignore me. There are several studies, mostly in Germany it seems, currently testing this so maybe we'll get some answers soon.

In the meantime, I try to get plenty of K1 and K2.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 07:01 PM

Also, on a side note, you aren't the original mscott are you?

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 07:01 PM

I wish I could see the full text of the 14654717 pubmed article that you posted. I wonder what the dose and delivery method of k1 and mk-4 were and if there were any dose dependent effects or favorable but statistically non significant effects that were unreported in the abstract. Other than that, +1 for a Very solid answer.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 16, 2014
at 02:36 AM

Interestingly I stumbled across this, rejuvenation-science.com/n_vitamin-k2-artery.html . It's relevant and I'm really posting it just for reference. It shows that the dose may be the relevant factor when it comes to k1, though again, this is in rats.

0
56c28e3654d4dd8a8abdb2c1f525202e

(1822)

on March 15, 2014
at 05:06 PM

No evidence whatsoever, simply offering an hypothesis consistent with all data. Surprised that South Japan vs Northern Japan has not been mentioned. Population and yet are homogeneous except for natto. To me that is very strong evidence.

0
56c28e3654d4dd8a8abdb2c1f525202e

(1822)

on March 15, 2014
at 03:12 PM

All these studies are in rats. Rats also produce their own vitamin C, and we do not. The studies which show an effect of vitamin K2 on humans and the studies on rats are consistent with the hypothesis of diminished K2 formation inside the human body. There would be variance in the human capability to form K2, similar to our very variable ability to form retinol from carotenes.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 03:31 PM

Do you have evidence that the mechanism by which rats convert k1-k2 is exclusive to rats? It seems from the article posted by moors and from citation #11 from my post that this mechanism would at least be similar in humans and that there's no reason to think otherwise.

0
10ec51c0e6e41939215a55316ad3d0b7

on March 15, 2014
at 12:51 PM

Just wanted to post another Mercola article that more explicitly describes the vitamin K forms and fates in the body:

http://articles.mercola.com/sites/articles/archive/2010/08/26/this-could-be-even-bigger-than-the-vitamin-d-discovery.aspx

Appears that the body mostly uses K1 for blood clotting processes, while the K1 that reaches gut bacteria and converted to K2 are mostly not absorbed and passes out of the body (and maybe used by the bacteria).

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 01:24 PM

http://www.ncbi.nlm.nih.gov/pubmed/9446847

0
96440612cf0fcf366bf5ad8f776fca84

(19463)

on March 15, 2014
at 12:24 PM

Like beta carroteen conversion to retinol, K1 to K2 conversion is limited and happens only in small amounts. You need the real thing.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 01:20 PM

Hey Raydawg, I used to think exactly what you're saying. However after reading through this wikipedia page and the appropriate citations I'm seeing that "In fact, tissues that accumulate high amounts of MK-4 have a remarkable capacity to convert up to 90% of the available K1 into MK-4.". This means that the authors of the Calcium Paradox and Mercola are right that the k2 produced by bacteria in the gut is not readily absorbed through the intestines, however, this also means that the k1 -> k2 conversion happens quite efficiently (90%) at a cellular level!

0
47cbd166d262925037bc6f9a9265eb20

(55)

on March 15, 2014
at 11:04 AM

I was about to ask the same question more plainly yesterday. Vitamin K1 is also converted to vitamin K2 in mitochondria via UBIAD1:

http://dev.biologists.org/content/140/8/1713.abstract

My nutritiondata analysis shows ~1499 mcg vitamin K and I also consume chicken liver, which is supposed to have some vitamin K2. I also eat marrow of some of the bones of my broth and that is supposed to have some K2 also.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 12:00 PM

Oh, interesting link, +1!

0
5ae3774df8015b4d7801f6642bc89f97

on March 15, 2014
at 06:49 AM

Probably no.

There is a great book on the importance of K2 called Vitamin K2 and the Calcium Paradox: How a Little Known Vitamin Could Save Your Life by Dr. Kate Rheaume-Bleue.

It's worth reading but here is a link that sort of summarizes the book. http://articles.mercola.com/sites/articles/archive/2012/12/16/vitamin-k2.aspx

It doesn't directly answer your question but based on their explanations it seems very unlikely that the conversion would produce enough K2 to make a difference.

Cb9a270955e2c277a02c4a4b5dad10b5

(10979)

on March 15, 2014
at 12:04 PM

Based on what I've read, the main reason k2 is advertised over k1 is because of a study that shows measurable reductions in bone fracture and CHD deaths in diets rich in k2 but not k1. These were epidemiological studies. I'm beginning to question these studies based on the premise that maybe even the highest percentage of k1 groups were not high enough to see a measurable difference. I agree that based on their explanations it doesn't seem like the conversion would make a difference, however,based on their explanations all the conversion happens in the gut, which is now shown to be false.

0
0ba891d22837788c4d5ccf3f33f60329

on March 15, 2014
at 05:13 AM

Since K1 to K2 conversion in humans hasn't really been studied in humans as far as I know, so I would be hesitant to think both forms will have the same effect. Also, even in rats K2 seems superior to K1 in preventing calcification brought about the the vitamin K antagonist blood thinner warfarin

Despite their similar in vitro cofactor activity we show that MK-4 and not K1 inhibits warfarin-induced arterial calcification
This seems somewhat supported by observational evidence like the Rotterdam study:
The relative risk (RR) of CHD mortality was reduced in the mid and upper tertiles of dietary menaquinone compared to the lower tertile [RR = 0.73 (95% CI: 0.45, 1.17) and 0.43 (0.24, 0.77), respectively]. Intake of menaquinone was also inversely related to all-cause mortality [RR = 0.91 (0.75, 1.09) and 0.74 (0.59, 0.92), respectively] and severe aortic calcification [odds ratio of 0.71 (0.50, 1.00) and 0.48 (0.32, 0.71), respectively]. Phylloquinone intake was not related to any of the outcomes.
I think good clinical evidence shows both K1 and K2 MK4 have similar benefits on insulin sensitivity, fracture prevention, and possibly cancer. But I think K2 will be better than K1 in calcification prevention, partly because I think the menaquinones are better at activating the enzyme MGP. Although there is still essentially no controlled evidence on vitamin K and calcification in humans, so feel free to ignore me.

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