Posted on August 2, 2011 -
A new study has linked vitamin K2 levels with reduced risk of advanced prostate cancer. In this study, the European Prospective Investigation into Cancer and Nutrition, over 11,000 men were studied by means of a dietary questionnaire. Vitamin K had already shown that it had anti-carcinogenic activity against cancer cells in a laboratory, but here they could observe how both vitamin K1 and K2 affected the rates of developing prostate cancer in a functioning population, over nearly 10 years.
Observations indicated that the higher the intake of K2 the lower the risk of all forms of prostate cancer. But the most significant protection offered by vitamin K2 was against advanced prostate cancer, in which case it was associated with a 63% reduction in risk. Vitamin K1, found mostly in leafy greens, showed no protective activity here, though other studies have shown it to be helpful in preventing osteoporosis. Dietary Intake of Vitamin K and Risk of Prostate Cancer
Vitamin K is known mostly for its clotting ability in the bloodstream, and in fact blood-thinning medications like Warfarin work by blocking vitamin K in the body. This now leads me to the idea that these types of medications could increase risk of prostate cancer in users. (Those on blood thinners are forbidden from using supplemental vitamin K and are even told to avoid K1 found in leafy greens.) Another important function of vitamin K is to direct calcium into the correct channels. This means guiding calcium towards the bones and teeth and not allowing it to build up in the arteries. So, vitamin K is important to help prevent arteriosclerosis, as well as osteoporosis.
Vitamin K2 is not commonly found in the North American diet due to the fact that it exists mostly in the meat and dairy products from grass-fed animals, and commercial cattle and dairy farms now feed their animals grains. Cultures such as the Japanese who do not traditionally consume dairy products have derived it from “natto” a fermented soya bean food. Because some vitamin K is produced and transformed (from K1 into K2) in the intestinal tract, those on long-term antibiotic treatments can be at a higher risk of K deficiency than most of the population.
There are two supplemental forms of vitamin K2, one is referred to as MK4 and the other as MK7. While MK4 has the most science behind it and is used medically in Japan to treat osteoporosis, it only works in milligram amounts (up to 45mg for therapeutic purposes) and milligrams of vitamin K2 are not allowed for sale in Canada. Since the Canadian regulators of supplements restrict levels of vitamin K2 to microgram levels, the only choice for Canadians is the MK7 version of the vitamin. While it has less science it is effective at microgram levels (120mcg to 240mcg) and so is pretty much the only option for products purchased in Canada.
I would like to close with an idea offered to me by Carmine Sparanese, the general manager of LifeStyle Markets, here in Victoria. As I mentioned in the last blog there is some restraint required in our new fascination with vitamin D. Since the body stores a lot of vitamin D that it would obtain from sunshine in an inactive form, converting it into an active form as required, we should be careful with supplements of vitamin D as they are all the active form, D3. In other words we are ingesting an “end product” instead of a precursor, or building block that allows the body to produce as much of the end product as it optimally requires.
Well, Carmine pointed out to me that when the levels of circulating D3 get too high and they mobilize calcium into the bloodstream, even if we haven’t hit the danger zone of hypercalcemia, we may still have a problem. Because most of us are deficient in vitamin K we don’t have enough of that nutrient circulating to guide this extra calcium to where it belongs, in bones and teeth. We then face the danger that some of this calcium will deposit in inappropriate places like the joints, leading to arthritic conditions, and worse, the arteries, leading to calcification or “hardening” of the arteries, a condition that leads to heart disease.
Therefore, those of us taking anything more than 3 to 5,000IU of vitamin D3 daily should definitely consider adding a vitamin K2 supplement to their regimen for that reason alone.