Here is the link
http://www.lmreview.com/articles/view/vitamin-d-and-vitamin-k-team-up-to-lower-cvd-risk-part-II/
Putting all the techno mumbo jumbo aside, my root question is simple; foe a person taking coumadin, would taking 45mcg of K2 help prevent calcium build-up in arteries and valves.
Even with open heart surgery and all the meds that come with it, I feel strongly a patient can reach a relatively high level of health with the right lifestyle. If coumadin does indeed contribute to calcium deposits in the wrong places, and contributes to weak bones, then I want to do what I can to stop it. All I am suggesting is a collective input to help one another.
Todd, i don't know if this helps answer your basic question
here is the 'rat" study
http://bloodjournal.hematologylibrary.org/cgi/content/full/109/7/2823
Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats
"To induce vascular calcification, rats (n = 30) received a diet containing warfarin (3 mg/g food) and vitamin K1 (1.5 mg/g food; the minimal dose required for rats is 0.5 µg/g food), according to the method described earlier by our group.25 These animals are designated as the W&K group. Control rats (n = 18) received no warfarin and a normal dose of vitamin K1 (5 µg/g food; this is equivalent to the vitamin K amount in normal standard rat food). From the control group, 6 rats where killed at the start of the experiment to measure the baseline calcium content of the abdominal aorta and left carotid artery. After 6 weeks of treatment, 6 control rats and 6 W&K rats were killed to monitor the effect of treatment. The remaining rats in the W&K group (n = 24) were subdivided into 4 groups of 6 rats for another 6-week treatment. One group continued the W&K diet, whereas warfarin was discontinued in the remaining 3 groups: one group received normal vitamin K1 (5 µg/g food), one group received high vitamin K1 (100 µg/g food; the dietary vitamin K requirements for rats are 0.5 µg/g food to maintain normal blood clotting), and the last group received high vitamin K2 (menaquinone-4, 100 µg/g food). In addition, the remaining 6 control rats continued their diet for another 6 weeks "
I "believe" the reason they stopped the Coumadin for the 3 groups, was they weren't really interested in Coumadin and Vit K, they just used the Coumadin to cause the vascular calcification, so they could see what effect the different levels of Vit k1 and high dose K2 would have on the calcification.
From the intro
"The rat arterial calcification model, as developed by Price et al20 and used by others,21,25,29 has thus far only looked at the development of arterial calcification. The aim of the present study was to use the rat arterial calcification model to investigate whether maximal MGP activity, ascertained by high–vitamin K intake, may stop the progression or even induce a reversal of warfarin-induced arterial calcification and the associated decrease in arterial distensibility"
Also for the Rotterdam study mentioned above (hooks post #13) that showed the benefit with just 45mcg of K2 a day
“The effect of K1 and the conversion rate of K1 to K2 was due to the extremely high dose of K vitamins used in this model,” said Schurgers. “This would be probably less in a normal diet, even with supplemental K1. In contrast, the Rotterdam study showed a significant protective benefit with Natural Vitamin K2 at just 45mcg per day, whereas K1 had no correlation at all"
Here is a link to the Abstract
http://www.ncbi.nlm.nih.gov/pubmed/15514282
Vitamin K-dependent proteins, including matrix Gla-protein, have been shown to inhibit vascular calcification. Activation of these proteins via carboxylation depends on the availability of vitamin K. We examined whether dietary intake of phylloquinone (vitamin K-1) and menaquinone (vitamin K-2) were related to aortic calcification and coronary heart disease (CHD) in the population-based Rotterdam Study. The analysis included 4807 subjects with dietary data and no history of myocardial infarction at baseline (1990-1993) who were followed until January 1, 2000. The risk of incident CHD, all-cause mortality, and aortic atherosclerosis was studied in tertiles of energy-adjusted vitamin K intake after adjustment for age, gender, BMI, smoking, diabetes, education, and dietary factors. The relative risk (RR) of CHD mortality was reduced in the mid and upper tertiles of dietary menaquinone compared to the lower tertile [RR = 0.73 (95% CI: 0.45, 1.17) and 0.43 (0.24, 0.77), respectively]. Intake of menaquinone was also inversely related to all-cause mortality [RR = 0.91 (0.75, 1.09) and 0.74 (0.59, 0.92), respectively] and severe aortic calcification [odds ratio of 0.71 (0.50, 1.00) and 0.48 (0.32, 0.71), respectively]. Phylloquinone intake was not related to any of the outcomes. These findings suggest that an adequate intake of menaquinone could be important for CHD prevention.
heres the fulltext
http://jn.nutrition.org/content/134/11/3100.long
I'm not sure if it helps with your question tho, since they studied the general population and their diets and not people on Coumadin, for their study. So if their study showed 45 mcg a day lowerred their risks, I don't know what effect Coumadin would have on it, since it blocks the Vit K from doing its job. Most likely someone on Coumadin would need more than the 45 a day.
Also IF you increased your levels of Vit K2, most likely you would have to increase your Coumadin to keep your INR in range so it MIGHT be a catch 22 type of thing.