In 1945, an American dentist Weston Price presented evidence of a fat soluble substance present in dairy products which played a fundamental role in the utilization of minerals which were essential for the prevention of dental caries and a range of common chronic diseases. Price was unable to determine the chemical composition of the substance and referred to it as “Activator X”, which he discovered was present in fish eggs, egg yolks, some organ meats and especially in butter made from the milk from grass-fed cows. He found that by advising patients to include butter oil in their diet virtually all of them were overcome teeth decay without having to resort to drilling and filling.
It is only in recent years that Activator X has been identified as vitamin K2(VK2) which is a group of chemicals based on the menaquinones. Furthermore we now have a much better understanding of the function of the vitamin in the body and the main dietary sources. In particular it is evident that insufficiency of VK2 is a contributing factor to many of the current health problems. However it is important to understand that the vitamins K1 and K2 have quite different characteristics. K1 facilitates blood clotting and is present in all photosynthetic plants. Because it is widely available a deficiency rarely occurs. K1 is phylloquinone which can be converted into K2 in the body but the rate of conversion is slow and therefore unable to meet the requirements. The key role of VK2 is to facilitate the utilisation of vitamins A and D as well as calcium(1).
ROLE OF VITAMIN K2 IN VARIOUS DISEASES/CONDITIONS
Heart Disease
In the Rotterdam study data were collected from 4581 men and women aged 55 or more years over a 7-year period. There were 99 deaths related to heart disease and 602 deaths from other causes. It was found that those in the highest tertile of vitamin K2 intake had a reduction of over 50% in the death rate due to heart disease when compared with those in the lowest tertile. There was a reduction of about 25% in the all-cause death rate. The main dietary sources of vitamin K2 were eggs, meat and cheese. Rather interestingly the authors commented that the observed reduction in coronary risk was not related to a healthy lifestyle. It was also reported that the degree of severe aortic calcification was inversely related to the level of VK2. The VK2 is needed to activate matrix gla protein(MGP) which prevents calcium from depositing on blood vessels. Hence the greater the deficiency of VK2 the less MGP will be present which will be reflected in the degree of calcification resulting in hardening and thickening of the arteries(atherosclerosis). Because of the widespread concern about cholesterol(which is totally unjustified see BLOG 8)many people are avoiding butter and other milk products which contain fat. Invariably this means that they reduce their intake of VK2 with the inevitable result that they are make things worse not better!(2)
In fact studies with rats have shown that increasing the level of VK2 in the tissue was associated with a reduction in calcification and that the arterial flexibility was restored when the calcium had been removed. This suggests that there is some scope for recovery(3) which is confirmed by the finding that a high intake of VK2 was associated with a 20% reduction in the degree of coronary calcification in humans(4).
Bone Health
Despite the fact that many people are taking calcium supplements, osteoporosis is a very common condition. As a consequence, the bones are weakened and can easily break. Vitamin D is required for calcium deposition into the bones and teeth but is also critically dependent on the protein osteocalcin. VK2 is needed to activate the osteocalcin : if this is not present in sufficient quantity the calcium will not be utilised. In Japan, the intake of calcium is much lower than in the UK or the USA but the incidence of osteoporosis is relatively scarce. Almost certainly this can be attributed to the regular consumption of natto, a fermented food prepared from soya, which has a particularly high content of VK2.
A study by a Japanese research team found that the concentration of VK2 in post-menopausal women living in the Tokyo area where natto consumption is relatively high was about 4 times greater than in those located in Hiroshima. A comparison of the amount of natto consumed in various districts throughout Japan found that there was a very good inverse statistical relationship with the incidence of hip fractures. In other words the more natto consumed the less chance of experiencing a fracture of the hip. This project also noted that the VK2 levels in the blood of British women were much lower than in any of the Japanese women in the study(5).
Patients who receive organ transplants have a much higher risk of bone fractures than age-matched controls. In men who had heart transplants the rate of fractures was increase by a factor of 13 but in women with kidney transplants the value was 34(6).
A recent study in Norway has found that much of the bone loss that occurs in transplant patients can be prevented by supplementation with VK2. In the treatment group which received the VK2 the bone mineral density of the lumbar spine and the bone mineral content were higher than in the controls which did not have the VK2 supplements(7).
Diabetes
There are a number of reasons which indicate that a relative lack of VK2 contributes to the development of type 2 diabetes (T2D):
- When a deficiency of VK2 is induced in laboratory animals they develop T2D
- A characteristic of diabetics is that the organs become resistant to insulin. Research has shown that VK2 improves sensitivity to insulin (ie reduces the resistance). This is confirmed by Japanese research which shows that the VK2 status is inversely related to insulin resistance in diabetics
- The sugar content of haemoglobin is used as a indicator of the seriousness of diabetes in an individual. It has been found that the greater the deficiency of VK2 the higher the value of this test(8).
It has been established that VK2 has a growth inhibitory effect on various types of cancer cells in vitro, and its efficacy has been demonstrated in clinical applications in a number of patients with leukemia and hepatocellular carcinoma(9).
The European Prospective Investigation of Cancer and Nutrition (EPIC) is a major study into the relationship between diet and cancer. Results obtained from 11.438 men and 12,902 women from Heidleberg were analysed to determine the relationship between the intake of vitamins K1 and K2 and the incidence of various cancers. During a 10-year period there were 1755 cases of cancer, which included 458 deaths. It was found that cancer incidence and cancer mortality decreased with higher intakes of VK2, whereas VK1 was not associated with a decreased cancer risk. Those with the highest intake of VK2 had a reduction in cancer mortality of 39% when compared with those who had the lowest intake
Cancer risk reduction with increasing intakes of VK2 was more evident in men than in women. There was a significant inverse association of VK2 with the incidence of lung and prostate cancer in men. This inverse association between intake of VK2 and cancer incidence is in line with the observation of anticarcinogenic effects of vitamin VK2 in a variety of cancer cell lines. In male participants, the most frequent cancer sites were prostate, colorectum, and lung, of which prostate and lung cancer were individually influenced by dietary intake of VK2. In contrast, almost 50% of all cancer cases in women were breast cancer, which was not significantly associated with intake of VK2(10).
Other conditions
In her recent book Kate Rheaume-Bleue “Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life”(8) has pulled together much of the available research on VK2. For anyone who would like to investigate the role of VK2 in greater detail I would recommend this publication.
In particular she explains that in addition to the diseases described here that an insufficiency of VK2 is likely to be a contributing factor to:
- Alzheimer’s Disease
- Arthritis
- Kidney disease
- Infertility and difficulties during childbirth
- Abnormal facial development
It is also important to recognise the original work of Weston Price who demonstrated that VK2 prevents the development of dental caries and can even facilitate the recovery of teeth which have been damaged.
The next Blog will explain what you can do to ensure your diet contains an adequate supply of VK2.
REFERENCES
- C Masterjohn (2008) http://www.westonaprice.org/fat-soluble-activators/x-factor-is-vitamin-k2#fig4
- J M Geleijnse et al (2004) Journal of Nutrition 134 pp 3100-3105
- L J Shurgers et al (2006) Blood 109 (7) pp 2823-2831
- J W J Beulens et al (2009) Atherosclerosis 203 (2) pp 489-493
- M Kaneki et al(2001) Nutrition 17 (4) pp315-321
- R Ramsay-Goldman et al (1999) Journal of Bone Mineral Metabolism 14 (3) pp 456-467
- L Forli et al (2010) Transplantation 89 (4) pp458-464
- K Rheaume-Bleue (2012) Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life. John Wiley & Sons Canada
- H Tokita et al (2006) International Journal of Molecular Medicine 17 (2) pp 235-24
- K Nimptsch et al (2010) American Journal of Clinical Nutrition 91(5) pp1348-1358