There is no vitamin K... there is a GROUP of vitamins K... surprising but true!
With this statement I would like to start debugging one of the biggest myths related to health.
First of all, we must clearly say that there are more than just One vitamin K! Usually, when we go and ask for a vitamin K, we will get... K1, also called phylloquinone, phytomenadiona or phytonadione, which is to help with blood clotting.
However, there is also another one called K2 (in fact there are more within the K2 group), which plays significantly different role to vitamin K1. Unfortunately, on many websites and during many lectures, these two are still mixed up which results in many misunderstandings.
Let’s briefly describe K1 and then go to more information related to K2 group with main emphasis on K2-MK7.
The main sources of K1 are leafy vegetables and it is mainly related to improving blood clotting. K2 was first discovered by researches form the Harvard Medical School. There are two main types of it: MK4 and MK7. MK4 is produced in animal tissue and its main source is meat, egg yolk and butter. MK7 is produced in the human gut by bacteria. Even though there is a mechanism in the intestines which allows the conversion of vitamin K1 to K2, the amount converted is usually so small that it has no major significance.
Booth SL. skeletal functions of vitamin K-dependent proteins: not just for clotting anymore.
Nutr Rev 1997, 55(7):282-84
Suttie JW. The importance of menaquinones in human nutrition. Annual Review of Nutrition 1995; 15:399-417.
doi: 10.1146/annurev.nu.15.070195.002151. PMID 8527227
As I mentioned before, K2-MK4 is produced in animal tissue and its main source are meat, egg yolk and butter. However, when we come across supplements, they are usually produced artificially (isolating it naturally is very expensive and therefore usually avoided by manufacturers) as an extract from the tobacco plant (Nicotiana tabacum).
When we speak about MK4, there is a problem with it related to its short half-life. In order to take a significant advantage of it, it would have to be in the body for a certain period of time and at the high enough level. Some researches claim that to achieve any positive results from consumption of K2-MK4, it would need to be taken at least 3 times a day 15 mg each time. On the other hand, as you will see a bit later, there are some studies confirming its great therapeutic effect on cancer cells.
K2-MK7, also called menaquinone, has a lot longer half-life then K2-MK4. Because of this, it can be taken only once per day. As you will see later, it is more important for us, at least in some respect. The natural source of it is natto.
For those who are interested in further research on K1 and K2 comparison, here is an interesting link:
Schurgers LJ et al. Vitamin K-containing dietary supplements: comapraison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood 2007; 109(8): 3279-83
One of the most important features of K2-MK7 is the fact that it activates two protein compounds: osteocalcin (BGP – bone gla protein) and MGP (matrix gla protein).
The activation process is called: Gamma-carboxylation and is shown in a diagram below:
In simple terms:
-vitamin K2 activates a number of special proteins that move calcium around the body. Most importantly, K2 activates a protein called osteocalcin which attracts calcium into bones and teeth.
-another important role of K2 is in activating the protein called matrix gla protein (MGP) which takes calcium out of soft tissue like arteries and veins.
These two processes are extremely important in both prevention and actual reversing atherosclerosis.
Because osteocalcin is measured in HBS check-up (more information on HBS and bioresonance will be provided soon), let me explain a bit more what it is:
Osteocalcin, also called bone gla protein- BGP , is a biological protein found in bones and teeth, and it’s certainly the most abundant protein in bone just after the collagen, that is used to form the matrix which holds calcium. Another reason for which osteocalcin is so important is the fact that in the light of some new research, it acts as a hormone that causes the pancreas to secrete more insulin and increase sensitivity to insulin at the cellular level; needless to say how important it is for diabetics!
Lee NK, Sowa H, Hinoi E, et al. Endocrine regulation of energy metabolism
by the skeleton. Cell 2007,130(3):456-69
Conditions and diseases associated to vitamin K2 deficiency
-Increase risk of cancer (including breast, prostate, and liver)
Some examples of disease and treatments
Let me go through some examples of diseases mentioned above that make supplementation with K2 really important:
Apart from the usual health concerns related to osteoporosis, there is one more which is less mentioned and is related to a situation occurring after organ transplants. There is a substantial and quite rapid decrease in bone mineral density which occurs within the first year of the transplant and it is related to almost all types of organ transplant. This problem is that the disease itself promotes a sort of bone loss, on top of that many medications increase this unfortunate process and it is exactly what we want to avoid after a transplant. It is really vital for all participants to intake enough amounts of K2 in order to limit this degeneration.
2. Alzheimer disease
It has been well documented that vitamin K2 deficiency increases risk for diabetes and that alone may predispose us to develop Alzheimer’s. Diabetics have a 30%-65% higher risk of developing Alzheimer’s disease. As I have mentioned above, K2 increases the brain’s production of and sensitivity to insulin and it may prevent the generation of free radicals that contribute to senile plaques and tangles. There are few characteristic features related to the brain of a person suffering from Alzheimer’s disease. First of all, we must realize that unlike cells in the whole body, brain cells don’t need insulin to absorb glucose. However, insulin is vital for brain function; especially to assist learning process and to support forming memories. Secondly, we know today, that the brain of a person suffering from Alzheimer’s disease is very much like the diabetic body and we might encounter one of the two scenarios: either the brain isn’t producing enough insulin (like in case of type 1 diabetes) or the brain cells become resistant to insulin (like in case of type 2 diabetes). Thirdly, we know that the Alzheimer’s brain doesn’t use the glucose properly and therefore, administration of insulin or improving insulin sensitivity does improve the cognitive performance of Alzheimer’s patients, and it has demonstrated that it may prevent or reverse the disease.
Craft S. Insulin resistance syndrome and Alzheimer’s disease: age-related
and obesity-related effects on memory, amyloid, and inflammation.
Neurobiol Aging 2005 Dec, 26(Suppl) 1:65-69
Allison AC. The possible role of vitamin K deficiency in the pathogenesis
of Alzheimer’s disease and augmenting the brain damage associated with
cardiovascular disease. Med Hypotheses 2001 Aug, 57(2):151-55
There are some new studies that demonstrate beneficial effect of K2 to cancer prevention. It has been observed in both animal and human cell tissue (in vitro) that K2 has anti cancer activities. One of the first studies has been done by The European Prospective Investigation into Cancer and Nutrition (EPIC) and the concussion was that a higher intake of K2 is directly associated with a significant reduction of developing cancer.
Nimptsch K, rohrmann S, Kaaks R, et al. Dietary vitamin K intake in relation to cancer
incidence and mortality: results from the Heidelberg Cohort
of The European Prospective Investigation into Cancer and Nutrition
(EPIC-Heidelberg). AM J Clin Nutr 2010, 91(5):1348-58
The above cited study emphasized that the reduction of cancer risk was also related to the following types of cancer:
1. Prostate cancer
2. Lung cancer
3. Liver cancer
Link to the study about the liver cancer:
Habu D, Shiomi S, Tamori A, et al. Role of vitamin K2 in the development
of hepatocellular carcinoma in women with viral cirrhosis of the liver.
JAMA 2004 Jul 21, 292(3):358-61
Link to the study of Leukemia:
Yaguchi M, Miyazawa K, Katagiri T, et al. Vitamin K2 and its derivatives
Induce apoptosis in leukemia cells and enhance the effect of all-trans retinoic acid.
Leukemia 1997, 11(6):779-87
This study has demonstrated that menaquinone induces apoptosis (cell death) for all types of leukemia cell that were tested. What it means is that some abnormal white blood cells are forced to self-destruction, and some to differentiate into harmless white blood cells!
In the study, there are two outstanding examples:
-An 80-year old woman with myelodysplastic syndrome who received an oral dose of 45 mg a day of K2-MK4 and after 14 months her condition improved and she no longer needed any transfusion.
-A 72-year-old woman who had been diagnosed with acute leukemia. Even though she achieved remission with a conventional treatment, a relapse occurred about 8 months later. She was given 20 mg of vitamin K2-MK4 into her treatment which resulted in a complete disappearance of cancer within two months!
The benefits of taking K2
-K2 regulates how strong bones we will build before age of 20 and how much of it we will keep after menopause (females).
-K2 counteracts each of the pathological mechanisms related to estrogen declining which impact bone density.
-K2 helps prevent and reverse atherosclerosis:
Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary Intake of Menaquinone Is Associated
with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study. J. Nutr 2004,
-K2 activates osteocalcin which in turns acts as a hormone that causes the pancreas to secrete more insulin and increase sensitivity to insulin at the cellular level (mentioned already above with an appropriate link to study).
-K2 will activate MGP which then will be able to reduce arterial calcium content by 50% just over 6 weeks! (a very efficient way of fighting atherosclerosis!)
-K2 helps restore arterial flexibility once the calcium has been removed!
Schurgers L. Regression of warfarin-induced medial elastocalcinosis by high
intake of vitamin K in rats. Blood 2007 Apr, 109(7):2823-31
A word regarding patients taking blood-thinning drugs like warfarin or heparin: these type of medication are to prevent the functioning of vitamin K1 which contributes to blood clotting. For the same reason patients are told to refrain from eating leafy vegetables. The only problem with this is that these medications also prevent vitamin K2 from performing its natural function leading to all the bad consequences related to K2 deficiency (of which I will write below in more detail) among which there are atherosclerosis, heart attacks and osteoporosis! However, there is a good news: there are some research studies done which confirm that if these patients take up to 50 mcg of K2 per day, no coagulation disorders will occur and yet the K2 intake will help prevent the formation of osteoporosis as well as remain providing some other benefits including reduction of arterial calcification and, surprisingly, provide more stability of the blood coagulation parameter – the one that we might be afraid of and because of which warfarin is prescribed!
Sconce E, Khan T, Mason J, et al. Patients with unstable control have poorer dietary
intake of vitamin K compared to patients with stable control of anticoagulation.
Thromb. Haemost. 2005;93:872-75
Schurgers L. Regression of warfarin-induced medical elastocalcinosis
by highintake of vitamin K in rat. Blood 2007;109(7):2823-31
K2 deficiency is also linked to Alzheimer’s disease which is well known to be the most common cause of dementia. It is interesting to state that even though K2 is not a classical antioxidant acting as such anywhere in the body (so it doesn’t donate electrons), it has shown a very powerful ability to prevent free radical accumulation and brain cell death in laboratory studies:
Li J, Lin JC, Wang H, et al. Novel role of vitamin K in preventing
oxidative injury to developing oligodendrocytes and neurons.
J Neurosci 2003 Jul 2, 23(13):5816-26
Dosage is usually determined based on the needs and the conditions of a patient and vary from 100 mcg to 500mcg per day.
I am absolutely certain that all the above cited studies have clearly demonstrated how important vitamin K2 is for our health. It is vital for everyone to have an appropriate intake of this vitamin for both prevention and therapeutic purposes.
The only important challenge is how to get the best quality one, and most likely natural, not synthetic.
Adam Przygoda, ND