Questions About K and Cardiovascular Health
Submitted by Life Extension
As we age, calcium that belongs in our bones begins to make its appearance in other unwanted areas, including inside the linings of major arteries. Over time, normal smooth muscle cells in artery walls transform into bone-like cells through the deposition of calcium, essentially turning sections of artery into non-resilient, inflexible bony tissue, unable to effectively regulate blood flow. This process lends literal reality to the term "hardening of the arteries," which we now know as late-stage atherosclerosis.
Nature has provided a powerful inhibitor of arterial calcification in the form of matrix Gla-protein, one of the 16 Gla-proteins activated by vitamin K. This specific Gla-protein is produced in arterial walls, but is only activated when sufficient vitamin K is present. In the absence of sufficient vitamin K, arterial calcification is able to continue unopposed, leading to advanced atherosclerosis and its deadly consequences, heart attacks, and strokes. Indeed, in older men and women who had the highest levels of inactive matrix Gla-protein (indicating low vitamin K levels), there was a nearly three-fold increased risk of cardiovascular disease compared to those with the lowest levels.
For nearly 20 years, researchers have known that insufficient vitamin K intake in the diet is related to atherosclerosis in the aorta, the body's largest blood vessel. Since that time, a host of basic science and laboratory studies have indicated that higher vitamin K intake is essential for preventing atherosclerosis in major vessels of all kinds. Animal studies even show that vitamin K can "rescue" calcified arteries that occur as a result of the overuse of drugs that inhibit vitamin K, such as certain blood thinners.
The Rotterdam Heart Study, a large-scale, well-controlled clinical trial that tracked 4,800 participants for seven years, revealed that participants who ingested the greatest quantities of vitamin K2 in their diet experienced a better cardiovascular condition than people who ingested the least. High intakes of vitamin K2 also corresponded to less calcium deposition in the aorta, whereas participants who ingested less K2 were more likely to show moderate or severe calcification. Animal studies suggest vitamin K intake not only blocks the progress of further calcium accumulation, but also induces 37% regression of preformed arterial calcification.
Humans get most of their vitamin K from green vegetables in the form of vitamin K1. The problem is that K1 is tightly bound to plant fiber and only a small fraction absorbs into the bloodstream.
Vitamin K2 (menaquinones) is found in meat, eggs, and dairy products and is also made by bacteria in the human gut, which provides a certain amount of the human vitamin K requirement. Human studies show that vitamin K2 is up to 10 times more bioavailable than K1. Vitamin K2 remains biologically active in the body far longer than K1. For instance, K1 is rapidly cleared by the liver within eight hours, whereas measurable levels of K2 (MK-7) have been detected 72 hours after ingestion.
Ideal Forms of Vitamin K2
In recent years, two forms of vitamin K2 have been extensively researched and the findings reveal vastly improved effects compared to K1. The MK-4 form of vitamin K2 is the most rapidly absorbed and is now routinely used in Japan to maintain healthy bone density. MK-4, however, only remains active in the blood for a few hours. The MK-7 form of K2, on the other hand, remains bioavailable to the human body over a sustained 24-hour period and to higher levels (seven to eightfold) during prolonged intake. Both MK-4 and MK-7 have demonstrated remarkable health benefits when studied in human populations.
The Most Complete Vitamin K Formula
Vitamin K1 is the form found in plants and vegetables and should be part of most people's daily supplement regimen. Even more important is inclusion of the MK-4 and MK-7 forms of vitamin K2. Based on data substantiating the longacting effects of MK-7, it is now possible to ingest fewer total micrograms of vitamin K but achieve far higher sustained blood levels of this critical nutrient.
The latest Super K with Advanced K2 Complex formula provides vitamin K1 and the MK-4 and MK-7 forms of vitamin K2 in just one daily softgel. The virtue of this formula is that it provides the precise amount of the long-acting MK-7 form of vitamin K2 that recent human studies have shown provides optimal K2 levels over a 24- hour period. The MK-4 is included to provide the rapid increase in vitamin K blood levels that may account for its beneficial effects in certain studies.
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