Vitamin K2: The Missing Nutrient

"Chris Kresser, M.S., L.Ac is a globally recognized leader in the fields of ancestral health, Paleo nutrition, and functional and integrative medicine." The Paleo diet excludes dairy and grains. I eat both dairy and grains myself. I am not advocating the Paleo diet, but it may be beneficial for those with allergies or sensitivities to milk or grains or gluten intolerance.

In the following article, he discusses the benefits of vitamin K2. 


by Chris Kresser


"A study recently published by the European Prospective Investigation into Cancer and Nutrition (EPIC) has revealed that increased intake of vitamin K2 may reduce the risk of prostate cancer by 35 percent. The authors point out that the benefits of K2 were most pronounced for advanced prostate cancer, and, importantly, that vitamin K1 did not offer any prostate benefits.

The findings were based on data from more than 11,000 men taking part in the EPIC Heidelberg cohort. It adds to a small but fast-growing body of science supporting the potential health benefits of vitamin K2 for bone, cardiovascular, skin, brain, and now prostate health.

Unfortunately, many people are not aware of the health benefits of vitamin K2. The K vitamins have been underrated and misunderstood up until very recently in both the scientific community and the general public.

It has been commonly believed that the benefits of vitamin K are limited to its role in blood clotting. Another popular misconception is that vitamins K1 and K2 are simply different forms of the same vitamin – with the same physiological functions.

New evidence, however, has confirmed that vitamin K2’s role in the body extends far beyond blood clotting to include protecting us from heart disease, ensuring healthy skin, forming strong bones, promoting brain function, supporting growth and development and helping to prevent cancer – to name a few. In fact, vitamin K2 has so many functions not associated with vitamin K1 that many researchers insist that K1 and K2 are best seen as two different vitamins entirely.

A large epidemiological study from the Netherlands illustrates this point well. The researchers collected data on the vitamin K intakes of the subjects between 1990 and 1993 and measured the extent of heart disease in each subject, who had died from it and how this related to vitamin K2 intake and arterial calcification. They found that calcification of the arteries was the best predictor of heart disease. Those in the highest third of vitamin K2 intakes were 52 percent less likely to develop severe calcification of the arteries, 41 percent less likely to develop heart disease, and 57 percent less likely to die from it. (Geleijnse et al., 2004, pp. 3100-3105) However, intake of vitamin K1 had no effect on cardiovascular disease outcomes.

While K1 is preferentially used by the liver to activate blood clotting proteins, K2 is preferentially used by other tissues to deposit calcium 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.(Spronk et al., 2003, pp. 531-537) In an acknowledgment of the different roles played by vitamins K1 and K2, the United States Department of Agriculture (USDA) finally determined the vitamin K2 contents of foods in the U.S. diet for the first time in 2006. (Elder, Haytowitz, Howe, Peterson, & Booth, 2006, pp. 436-467)

Another common misconception is that human beings do not need vitamin K2 in their diet, since they have the capacity to convert vitamin K1 to vitamin K2. The amount of vitamin K1 in typical diets is ten times greater than that of vitamin K2, and researchers and physicians have largely dismissed the contribution of K2 to nutritional status as insignificant.

However, although animals can convert vitamin K1 to vitamin K2, a significant amount of evidence suggests that humans require preformed K2 in the diet to obtain and maintain optimal health. The strongest indication that humans require preformed vitamin K2 in the diet is that epidemiological and intervention studies both show its superiority over K1. Intake of K2 is inversely associated with heart disease in humans while intake of K1 is not (Geleijnse et al., 2004, pp. 3100-3105), and vitamin K2 is at least three times more effective than vitamin K1 at activating proteins related to skeletal metabolism. (Schurgers et al., 2007) And remember that in the study on vitamin K2’s role in treating prostate cancer, which I mentioned at the beginning of this article, vitamin K1 had no effect.

All of this evidence points to the possibility that vitamin K2 may be an essential nutrient in the human diet. So where does one find vitamin K2 in foods? The following is a list of the foods highest in vitamin K2, as measured by the USDA:

Foods high in vitamin K2

• Natto
• Hard cheese
• Soft cheese
• Egg yolk
• Butter
• Chicken liver
• Salami
• Chicken breast
• Ground beef

Unfortunately, precise values for some foods that are likely to be high in K2 (such as organ meats) are not available at this time. The pancreas and salivary glands would be richest; reproductive organs, brains, cartilage and possibly kidneys would also be very rich; finally, bone would be richer than muscle meat. Fish eggs are also likely to be rich in K2.

It was once erroneously believed that intestinal bacteria are a major contributor to vitamin K status. However, the majority of evidence contradicts this view. Most of the vitamin K2 produced in the intestine are embedded within bacterial membranes and not available for absorption. Thus, intestinal production of K2 likely makes only a small contribution to vitamin K status. (Unden & Bongaerts, 1997, pp. 217-234)

On the other hand, fermented foods, however, such as sauerkraut, cheese and natto (a soy dish popular in Japan), contain substantial amounts of vitamin K2. Natto contains the highest concentration of K2 of any food measured; nearly all of it is present as MK-7, which research has shown to be a highly effective form. A recent study demonstrated that MK-7 increased the percentage of osteocalcin in humans three times more powerfully than did vitamin K1. (Schurgers & Vermeer, 2000, pp. 298-307)

It is important to note that commercial butter is not a significantly high source of vitamin K2. Dr. Weston A. Price, who was the first to elucidate the role of vitamin K2 in human health (though he called it “Activator X” at the time) analyzed over 20,000 samples of butter sent to him from various parts of the world. As mentioned previously in this paper, he found that the Activator X concentration varied 50-fold. Animals grazing on vitamin K-rich cereal grasses, especially wheat grass, and alfalfa in a lush green state of growth produced fat with the highest amounts of Activator X, but the soil in which the pasture was grown also influenced the quality of the butter. It was only the vitamin-rich butter grown in three feet or more of healthy top soil that had such dramatic curing properties when combined with cod liver oil in Dr. Price’s experiments and clinical practice.

Therefore, vitamin K2 levels will not be high in butter from grain-fed cows raised in confinement feedlots. Since the overwhelming majority of butter sold in the U.S. comes from such feedlots, butter is not a significant source of K2 in the diet for most people. This is yet another argument for obtaining raw butter from cows raised on green pasture.

New research which expands our understanding of the many important roles of vitamin K2 is being published at a rapid pace. Yet it is already clear that vitamin K2 is an important nutrient for human health – and one of the most poorly understood by medical authorities and the general public."


http://chriskresser.com/vitamin-k2-the-missing-nutrient


358 comments

Is Vitamin K2 the New Vitamin D?

This article is dated November 18, 2014, and appeared on Medscape. It is the opinion of one doctor, who admits from the start that he knows nothing about nutrition as it relates to chronic illness. As pointed out by one commenter, he goes on to prove his ignorance by stating that green, leafy vegetables are a good source of vitamin K2. Wrong! They are a good source of vitamin K1. Because the doctor's article is controversial, there are many comments revealing various viewpoints. Be sure to drag and drop the link below and read the comments. There is also a video of the doctor giving his talk.


"Hello and welcome. I am Dr George Lundberg, and this is At Large at Medscape.

I do not know anything about nutrition as it relates to chronic illness, including obesity. I used to think that was because, probably like you, I was taught so little about nutrition in medical school. I have spent a medical lifetime reading articles about nutrition, before and after publication. But I am still woefully ignorant of "nutritional truth."

Take vitamin D. The minimum daily requirement prevents rickets. But then, just a few years ago, it became popular to check vitamin D blood levels. And many people were found to have "low" vitamin D levels. Then many diseases were found to be associated with "vitamin D deficiency," except it turns out that many labs were not doing the tests in equivalent ways.

After a whole lot of fuss and study, the Agency for Healthcare Research and Quality (AHRQ) issued a report this year that finds no consistent correlation between vitamin D and health outcomes such as cardiovascular disease, all-cause mortality, several types of cancer, or bone health.^[1] Amazing.

Which Brings Us to Vitamin K

What do you know about vitamin K? It has something to do with blood coagulation, right? Yes, but that is vitamin K₁. I am asking about vitamin K₂. I bet you have not thought much about that vitamin.
Here are nine things every physician should know about vitamin K₂:

1. It exists.
2. It is essential for life and health.
3. There is currently no reliable blood test to measure it.
4. Your body makes a certain amount via menaquinone-4 (M-4) in your gut from vitamin K₁.
5. That may not be enough.
6. Your body probably needs more vitamin K₂ for disease prevention than it manufactures, so nutritional sources are important.
7. Foods rich in vitamin K₂ (often in the form of M-4 or M-7) include: natto (fermented soybeans); green, leafy vegetables; organ meats such as goose liver; grass-fed beef; dairy; eggs; and fish.
8. Or you can take nutritional supplements to achieve healthy levels of vitamin K₂.
9. Deficiencies of vitamin K₂ are now being reported in serious journals to be associated with—get this—all-cause mortality, cardiovascular disease, osteoporosis, diabetes, many forms of cancer, dementia, and chronic inflammation.

Sound familiar?
Is vitamin K₂ the ubiquitous disease-associated vitamin D-like deficiency, sans blood testing, all over again? A fad disease about to pop up, flourish, and disappear? Or is this a real, late-to-the-table, fundamental new understanding of possible causes of many common diseases, disability, and death? And if vitamin K₂ is taken correctly, will it result in prevention and treatment of same? Look it up; check it out.

I do not know how this is going to work out, but I have a hunch that vitamin K₂ will turn out to be a really big deal rather than only "the new vitamin D," with much fuss and little substance.

Most of this research is being done in Japan and Europe, especially The Netherlands, well away from the US Department of Agriculture and lobbyists for the American food industry and its captured government and academic partners.

I owe my current interest in this topic to a product of the Internet as the world's greatest library—a well-educated, nonscientist who got really interested in this topic and will not let up. Thank you, Micki Jacobs of Cincinnati.

That's my opinion. I am Dr George Lundberg, at large at Medscape."

 http://www.medscape.com/viewarticle/834763?nlid=70845_1521&src=wnl_edit_medp_wir&uac=127701PY&spon=17

Update on Stopping Strontium before Total Calcium Test

I just got my latest total calcium results. I stopped taking strontium citrate for 17 days prior to my blood collection date of 11/13/2014. My result was 9.8 mg/dL, with a reference range of 8.5 to 10.5 mg/dL.

I began stopping the strontium for several days prior to blood draws as of 07/24/2012. I also switched laboratories on that date. My calcium results have all been normal. The 10.3 result of 07/24/2012 was high normal, according to the reference range for the new laboratory.

Collection Date     Stopped Strontium?          Total Calcium           Ref. Range

11/13/2014            Yes, 17 days before test          9.8                     8.5-10.5

11/12/2013            Yes, 12 days before test           9.5                    8.5-10.5 

07/24/2012            Yes, 11 days before test         10.3                    8.5-10.5

Prior to 07/24/2012, I was either not stopping my strontium or stopping just a day before blood collection. I had one high calcium result on 12/28/2009 (10.3 with reference range of 8.6-10.2 mg/dL). You will note all these earlier calcium tests were done at a different laboratory, with a different reference range.

Collection Date     Stopped Strontium?          Total Calcium           Ref. Range
12/09/2010            Yes, night before test               9.8                     8.6-10.2

12/28/2009                       No                                10.3 H                8.6-10.2

03/19/2009                       No                                   9.7                   8.6-10.2

01/06/2009                       No                                10.1                    8.6-10.2

The reason for stopping strontium for at least 12 days prior to blood or urine collection for calcium:

I have read that strontium reaches peak blood levels in 12 days of strontium intake. Servier, the manufacturer of strontium ranelate, has stated that sr. ranelate interferes with colorimetric tests for calcium. Automated total serum calcium tests are colorimetric. Urine calcium tests are usually colorimetric. If you stop taking strontium for 12 days or more, your blood level should be significantly lower than peak level. Therefore, it may be a good idea to stop taking strontium 12-14 days prior to having blood drawn for a total serum calcium and prior to collecting urine for a urine calcium test. Urine calcium values may vary considerably and are only meaningful if the patient is kept on a low-calcium, neutral-ash diet for three days before collection.

I’m not sure if stopping strontium citrate prior to specimen collection for calcium tests has made a difference for me or not, but I want to avoid another high calcium result. I have had one, and it was most likely falsely elevated by strontium.

Stopping Strontium Before Total Calcium Test

I started taking strontium citrate in 01/2008. In 2009, I had three tests for total serum calcium as part of three comprehensive metabolic panels (CMPs). On those occasions, I did NOT stop taking strontium prior to blood collection. The first two results were normal (10.1 & 9.7), but the third was slightly elevated (10.3, reference range 8.6 to 10.2 mg/dL). In 2010, I skipped my strontium dose the night before the test; my calcium was normal (9.8). In 2012, I switched labs and stopped taking strontium for 11 days prior to the test. My calcium was 10.3 but fell within the reference range (8.5 to 10.5 mg/dL) for the new lab. In 2013, I stopped strontium for 12 days before the test, and my calcium was 9.5.

Collection Date     Stopped Strontium?          Total Calcium           Ref. Range
01/06/2009                       No                               10.1                        8.6-10.2
03/19/2009                       No                                 9.7                        8.6-10.2
12/28/2009                       No                               10.3 H                    8.6-10.2
12/09/2010            Yes, night before test               9.8                       8.6-10.2
07/24/2012*          Yes, 11 days before test         10.3                     *8.5-10.5
11/12/2013            Yes, 12 days before test           9.5                      8.5-10.5 

*2012, switched labs-- Note different reference range.
All values are in mg/dL.

I have read that strontium reaches peak blood levels in 12 days of strontium intake. Servier, the manufacturer of strontium ranelate, has stated that sr. ranelate interferes with colorimetric tests for calcium. Automated total serum calcium tests are colorimetric. Urine calcium tests are usually colorimetric. If you stop taking strontium for 12 days or more, your blood level should be significantly lower than peak level. Therefore, it may be a good idea to stop taking strontium 12-14 days prior to having blood drawn for a total serum calcium and prior to collecting urine for a urine calcium test. Urine calcium values may vary considerably and are only meaningful if the patient is kept on a low-calcium, neutral-ash diet for three days before collection.

Using myself as a test subject, I do not have sufficient data to determine whether stopping strontium citrate for 12-14 days prior to a blood test significantly affects my total serum calcium levels. Stay posted. I am due for another blood test in a couple of weeks and am stopping strontium for more than 12 days before the test.