The importance of Vitamin K2

This is basically a post to thank the guys at veganicity.  I wanted to find a vegan vitamin K2 & these boys went out of their way to supply it!  So, this post is dedicated to them going the extra mile to supply something that I think will improve performance & longevity for all plant-based athletes over the longer term, so thanks guys!  & if you want to get a guaranteed vegan society approved vitamin K2 then I suggest you check out veganicity first.  The vitamin K2 can be found here & the main site for there substantial range of 100% vegan supplements can be found here.  You can get everything from multi-vits to digestive aids & everything inbetween (& they are nice blokes in person as well) so go check them out ... & they didn't even pay me for saying all that :-)
Now on with the actual post...

Would you like something that helps the blood clot, protects you from heart disease & arterial congestion, can fight off cancer & helps the bones stave-off osteoporosis? Welcome to the world of vitamin K!

Let’s start with the basics.  Vitamin K comes in several ‘flavours’; first off we have vitamin K1 (phytonadione).  If you are eating a variety of green leafy vegetables, then the chances are you will be getting enough of this vitamin.  It is found is chard, spinach, parsley, brussel sprouts & many other green, leafy foods.  If you are eating a variety of greens then getting this vitamin should not be an issue.

So, we have the first recommendation, eat you greens!

Let’s jump to the third member of the vitamin K family.  Vitamin K3 is a synthetic version (menadione).  It is used as a drug rather than a supplement & so we don’t really need to talk about it in this article.

The vitamin K that has people dancing in the streets right now is vitamin K2 (menaquinone).  This has two branches to its family tree MK4 & MK7.  MK4 is the easiest to cover as you can convert vitamin K1 directly into MK4 within the body & so as long as you are getting enough vitamin K1 you are likely to be getting enough vitamin K2 (MK4 type) – Note, that this is not gut dependant, it occurs within certain tissues of the body[i].  So, we can leave the MK4 version vitamin K2 behind as well for now & move onto the big player in the vitamin K2 family MK7.  So, why is MK7 different?  MK7 is produced by fermentation.  So, it can occur in some fermented foods[ii] & can also be produced in the gut by bacteria[iii].  

So, if we can produce it via gut & we get it from fermented foods, then why the hype about it?  First let’s look at some of the foods we can get it from.  Natto is fermented soya beans.  It is by far the highest source of vitamin K2 you can eat, the down side is it has the consistency of lumpy snot.  The way you can eat it is to mix it into soups, stews or rice after cooking.  Don’t try to eat it neat (like some of us did when we first got it!), it is pretty bad unless diluted & even then some people cannot stomach it.  Next up we have things like sauerkraut, this is a fermented cabbage; it is not as packed with vitamin K2 as natto, but still ok.  Again, this food is an acquired taste if you aren’t German (every German I know has eaten this).  I’ve contacted many of the major soya yoghurt manufacturers & so far they all say that soya yoghurt contains no vitamin K2 & I’m not sure about foods like tempeh as I’ve been unable to find any research done on the K2 levels in this food.

So, if you like natto & sauerkraut & are willing to eat those on regular basis, that, plus the bacteria in your body will mean that most people will probably have reasonable levels of vitamin K2.  Issues can arise though.  The first one is I’m betting that many of you do not fancy the idea of natto or sauerkraut on a regular basis.  If you don’t then there it is unclear exactly how much vitamin K2 is synthesised in the gut even though it has been shown to be a source of vitamin K2[iv]^,[v].  There are also several issues that can affect assimilation.  Gut health, bacteria in the gut, liver disease, even stress[vi] may affect gut assimilation.  So, if in any doubt you can always get take a vitamin K2 pill.  They are cheap & cover you just incase (always eat some food containing fat with your vitamin K supplement).

So, now you know all the differences between the vitamin K types, what does vitamin K2 do?  It seems that vitamin K2 has a special place in bone care, you can protect those bones by having vitamin K2 regularly[vii]^,[viii], so for those who may have bone issues or are post menopausal or are slightly older then taking note of your vitamin K2 may be something you should think about.  Next up we have cancer protection.  Cancer is one of the biggest killers in the western world, so if there is something that can help lessen your chances then everyone should be taking notice!  There are  many studies now where vitamin K2 has been shown to help cause the death of cancer cells before they get a chance to multiply & kill you[ix]^,[x]!  It can also help protect the liver[xi], it also helps alleviate calcium deposits in the cardiovascular system[xii], protects a person from heart disease[xiii]   & we are finding other benefits every day!

So, my final take home points are:

•         Make sure you are eating enough vitamin K1 foods (green leafy stuff),every day 
•          Eat a vitamin K2 source daily (natto, sauerkraut etc) or take a supplement
•         If you have any issues with cardiovascular health, liver illness, heart problems or cancer then talk to your medical professional about taking extra vitamin K2 (talk first, you may be on medication that doesn’t mix well with vitamin K2)
•        Blood thinners interfere with vitamin K utilisation & so consider talking to your medical professional about vitamin K supplementation if you are on any of these medications

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[i] Okano T, Shimomura Y, Yamane M, Suhara Y, Kamao M, Sugiura M,Nakagawa K. Conversion of Phylloquinone (Vitamin K1) into Menaquinone-4 (Vitamin K2) in Mice. The Journal of Biological Chemistry VOL. 283, NO. 17, pp. 11270–11279, April 25, 2008

[ii] Kaneki M, Hedges SJ, Hosoi T, Fujiwara S, Lyons A, St.John Crean, Ishida N, Nakagawa M, Takechi M, Sano Y. Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2.  Nutrition, Volume 17, Issue 4, Pages 315-321

[iii] Conly JM, Stein K, Worobetz L, Rutledge-Harding S. The contribution of vitamin K2 (menaquinones) produced by the intestinal microflora to human nutritional requirements for vitamin K. Am J Gastroenterol. 1994 Jun;89(6):915-23.

[iv] Conly JM, Stein K, Worobetz L, Rutledge-Harding S. The contribution of vitamin K2 (menaquinones) produced by the intestinal microflora to human nutritional requirements for vitamin K.  Am J Gastroenterol. 1994 Jun;89(6):915-23.

[v] Conly JM, Stein K.  The production of menaquinones (vitamin K2) by intestinal bacteria and their role in maintaining coagulation homeostasis.  Prog Food Nutr Sci. 1992 Oct-Dec;16(4):307-43.

[vi] Stress and the sensitive gut. Harvard Medical school http://www.health.harvard.edu/newsletters/Harvard_Mental_Health_Letter/2010/August/stress-and-the-sensitive-gut

[vii] Plaza SM, Lamson DW.  Vitamin K2 in bone metabolism and osteoporosis.  Alternative Medicine Review : a Journal of Clinical Therapeutic [2005, 10(1):24-35]

[viii] Shiraki M,Shiraki Y, Aoki C, Miura M.  Vitamin K2 (Menatetrenone) Effectively Prevents Fractures and Sustains Lumbar Bone Mineral Density in Osteoporosis.  Journal of Bone and Mineral Research.  Volume 15, Issue 3, pages 515–521, March 2000

[ix] Yoshida T, Miyazawa K, Kasuga I, Yokoyama T, Minemura K, Ustumi K, Aoshima M, Ohyashiki K.  Apoptosis induction of vitamin K2 in lung carcinoma cell lines: the possibility of vitamin K2 therapy for lung cancer.  Int J Oncol. 2003 Sep;23(3):627-32.

[x] Yaguchi M, Miyazawa K, Katagiri T, Nishimaki J, Kizaki M, Tohyama K, Toyama K.  Vitamin K2 and its derivatives induce apoptosis in leukemia cells and enhance the effect of all-trans retinoic acid.  Leukemia : Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K [1997, 11(6):779-87]

[xi] Habu D, MD, Shiomi S, Tamori A, Takeda T, Tanaka T, Kubo S, Nishiguchi S. Role of Vitamin K2 in the Development of Hepatocellular Carcinoma in Women With Viral Cirrhosis of the Liver.  JAMA. 2004;292(3):358-361. doi: 10.1001/jama.292.3.358

[xii] Schurgers LJ, Aebert H, Vermeer C, Bültmann B, Janzen J. Oral anticoagulant treatment: friend or foe in cardiovascular disease? Blood November 15, 2004 vol. 104 no. 10 3231-3232

[xiii] Gast GC, de Roos NM, Sluijs I, Bots ML, Beulens JW, Geleijnse JM, Witteman JC, Grobbee DE, Peeters PH, van der Schouw YT.  A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10. Epub 2009 Jan 28.