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Vitamin K content of foods and dietary vitamin K intake in Japanese young women. Kamao M, Suhara Y, Tsugawa N, Uwano M, Yamaguchi N, Uenishi K, Ishida H, Sasaki S, Okano T. J Nutr Sci Vitaminol (Tokyo). 2007 Dec;53(6):464-70. PMID: 18202532 Several reports indicate an important role for vitamin K in bone health as well as blood coagulation. However, the current Adequate Intakes (AI) might not be sufficient for the maintenance of bone health. To obtain a closer estimate of dietary intake of phylloquinone (PK) and menaquinones (MKs), PK, MK-4 and MK-7 contents in food samples (58 food items) were determined by an improved high-performance liquid chromatography method. Next, we assessed dietary vitamin K intake in young women living in eastern Japan using vitamin K contents measured here and the Standard Tables of Food Composition in Japan. PK was widely distributed in green vegetables and algae, and high amounts were found in spinach and broccoli (raw, 498 and 307 microg/100 g wet weight, respectively). Although MK-4 was widely distributed in animal products, overall MK-4 content was lower than PK. MK-7 was observed characteristically in fermented soybean products such as natto (939 microg/100 g). The mean total vitamin K intake of all subjects (using data from this study and Japanese food composition tables) was about 230 microg/d and 94% of participants met the AI of vitamin K for women aged 18-29 y in Japan, 60 microg/d. The contributions of PK, MK-4 and MK-7 to total vitamin K intake were 67.7, 7.3 and 24.9%, respectively. PK from vegetables and algae and MK-7 from pulses (including fermented soybean foods) were the major contributors to the total vitamin K intake of young women living in eastern Japan

"[Vitamin K and Bone Update. The biological effects of vitamin K(2) on bone quality.] Amizuka N, Li M, Guo Y, Liu Z, Suzuki R, Yamamoto T. Clin Calcium. 2009 Dec;19(12):1788-96. Japanese. PMID: 19949270 Post-transcriptional maturation with the presence of vitamin K(2) promotesgamma-carboxylation of osteocalcin, enabling further binding to hydroxyapatite, from which one could infer that vitamin K(2) increased the quality of bone matrix. For instance, vitamin K(2) rescued the impaired collagen mineralization caused by Mg insufficiency, by promoting a re-association of the process of collagen mineralization with mineralized nodules. Sodium warfarin, which antagonizes the function of vitamin K(2), reduced the binding of osteocalcin to bone matrices, and consequently resulted in crystalline particles being dispersed throughout the osteoid without forming mineralized nodules. Therefore,gamma-carboxylated Gla proteins mediated by vitamin K(2) appear to play a pivotal role in normal mineralization in bone."

[Vitamin K and Bone Update. In vivo Metabolism of Vitamin K. - In relation to the conversion of vitamin K(1) to MK-4 -] Okano T, Nakagawa K, Kamao M. Clin Calcium. 2009 Dec;19(12):1779-87. Japanese. PMID: 19949269 Phylloquinone is a major form (>90%) of dietary vitamin K, but the form of vitamin K that exists at the highest concentrations in tissues of animals and humans is menaquinone-4 (MK-4) . Despite this great difference, the origin of tissue MK-4 had not been clarified until recently. We demonstrated that deuterium-labeled phylloquinone was converted into deuterium-labeled MK-4 in mice and this conversion occurred following an oral or enteral administration, but not parenteral administration. By the oral route, the phylloquinone with the deuterium-labeled side chain (phytyl side-chain) was clearly converted into menaquinone-4 with a non-deuterium-labeled side chain (geranylgeranyl side-chain) , implying that phylloquinone was converted into menaquinone-4 via integral side-chain removal. Our results suggest that cerebral menaquinone-4 originates from phylloquinone intake and the release of menadione from phylloquinone in the intestine followed by the prenylation of menadione into menaquinone-4 in the intestine or tissues

Here all you need to know about vitamin K. The functions of vitamin K, Sources of vitamin K, and Symptoms of vitamin K deficiency.

The need for Vitamin K can be realized from the daily diet, without the need for fortification or supplements. Genesis Vitamin K deficiency is very rare. If you want to make sure that you get enough vitamin K intake, the best step is eating lots of vegetables, especially dark green leafy vegetables such as broccoli, kale, and cabbage. Tea and strawberries are also good sources of vitamin K is good. Some foods of animal origin, including egg yolks and liver, have small amounts of vitamin K.

Vitamin K is a fat-soluble vitamin. The "K" is derived from the German word "koagulation." Coagulation refers to the process of blood clot formation. Vitamin K is essential for the functioning of several proteins involved in blood clotting (1). There are two naturally occurring forms of vitamin K

Research has uncovered the fact that vitamin K also plays a crucial role in maintaining bone health. It was found that the amount of vitamin K required to halt bone absorption leading to osteoporosis requires much greater intakes than that required for blood clot regulation. Further, it appears that bone and vascular tissue (like coronary arteries) maintain a preference for a different form of vitamin K than that required for blood clotting regulation. Rather than vitamin K1 needed for clotting, vitamin K2 is the form preferred by bones and arteries (Schurgers LJ et al 2001). It appears that much of the information generated over the years for vitamin K focused on the K1 form, ignoring the K2 form necessary for bone and vascular health. Normal deposition of calcium occurs only in bone and in teeth. Abnormal deposition of calcium in the body occurs in three places: the inner lining of the arteries of the body (the intima) that causes atherosclerotic plaque; the muscle layer of arteries ("medial calcification"); and heart valves. K2 appears to be the form of vitamin K responsible for controlling these phenomena.

Vitamin K has been known as the coagulation vitamin, because of its role in the blood-clotting process. However, research over the last few decades has shown that the role of K Vitamins - and natural Vitamin K2, the menaquinones, in particular - has been greatly expanded. Of note, K Vitamins activity outside the liver is required for calcium utilization, the key factor in maintaining both bone and cardiovascular health.\n\nVitamin K2 helps to activate vitamin K-dependent proteins responsible for healthy tissues. In bone, it activates osteocalcin, a protein required to bind calcium to the mineral matrix, thus strengthening the skeleton. In circulation, Vitamin K2 participates in carboxylation of Matrix Gla Protein (MGP), the most potent inhibitor of arterial calcification known, lowering the risk of vascular damage.

Strong correlations have been noted between cardiovascular diseases and low bone density / osteoporosis-connections so strong that the presence of one is considered a likely predictor of the other. This relationship has led to the hypothesis that these conditions share core pathophysiological mechanisms. Recent advances in our understanding of the complimentary roles played by vitamin D3 and vitamin K2 in vascular and bone health provide support for this hypothesis, along with insight into key metabolic dysfunctions underlying cardiovascular disease and osteoporosis. Part II, The Vitamin K Connection to Cardiovascular Health, reviews the ways in which vitamin K regulates calcium utlization, preventing vascular and soft tissue calcification while complimenting the bone-building actions of vitamin D, and also discusses vitamin K safety and dosage issues, and the necessity of providing vitamin K and vitamin A along with vitamin D to preclude adverse effects associated with hypervitaminosis D.

Calcium, dairy foods, vitamin D, and colorectal cancer risk: the Fukuoka Colorectal Cancer Study. Mizoue T, Kimura Y, Toyomura K, Nagano J, Kono S, Mibu R, Tanaka M, Kakeji Y, Maehara Y, Okamura T, Ikejiri K, Futami K, Yasunami Y, Maekawa T, Takenaka K, Ichimiya H, Imaizumi N. Cancer Epidemiol Biomarkers Prev. 2008 Oct;17(10):2800-7. PMID: 18843026

Arachidonic acid and docosahexaenoic acid supplementation increases coronary flow velocity reserve in Japanese elderly individuals. Oe H, Hozumi T, Murata E, Matsuura H, Negishi K, Matsumura Y, Iwata S, Ogawa K, Sugioka K, Takemoto Y, Shimada K, Yoshiyama M, Ishikura Y, Kiso Y, Yoshikawa J. Heart. 2008 Mar;94(3):316-21. Epub 2007 Jun 25. PMID: 17591648 doi:10.1136/hrt.2006.113159

Marine-derived n-3 fatty acids and atherosclerosis in Japanese, Japanese-American, and white men: a cross-sectional study. Sekikawa A, Curb JD, Ueshima H, El-Saed A, Kadowaki T, Abbott RD, Evans RW, Rodriguez BL, Okamura T, Sutton-Tyrrell K, Nakamura Y, Masaki K, Edmundowicz D, Kashiwagi A, Willcox BJ, Takamiya T, Mitsunami K, Seto TB, Murata K, White RL, Kuller LH; ERA JUMP (Electron-Beam Tomography, Risk Factor Assessment Among Japanese and U.S. Men in the Post-World War II Birth Cohort) Study Group. J Am Coll Cardiol. 2008 Aug 5;52(6):417-24. PMID: 18672160 Conclusions Very high levels of marine-derived n-3 FAs have anti-atherogenic properties independent of traditional cardiovascular risk factors and may contribute to lower burden of atherosclerosis in Japanese in Japan, which is unlikely due to genetic factors.

Vitamin K epoxide reductase complex and vascular calcification: is this the important link between vitamin K and the arterial vessel wall? Spronk HM. Circulation. 2006 Mar 28;113(12):1550-2. Review. PMID: 16567578

Strong correlations have been noted between cardiovascular diseases and low bone density / osteoporosis-connections so strong that the presence of one type of pathology is considered a likely predictor of the other. This potentially causal relationship has led to the hypothesis that these conditions share core mechanisms. Recent advances in our understanding of the complimentary roles played by vitamin D3 and vitamin K2 in vascular and bone health provide support for this hypothesis, along with insight into key metabolic dysfunctions underlying cardiovascular disease and osteoporosis. Part I of this review summarizes current research linking vitamin D deficiency to cardiovascular disease, the physiological mechanisms underlying vitamin D's cardiovascular effects, and leading vitamin D researchers' recommendations for significantly higher supplemental doses of the pro-hormone. Part II reviews the vitamin K connection to cardiovascular disease; the ways in which vitamin D and vitamin K pair up to prevent inflammation, vascular calcification and osteoporosis; and the necessity of providing vitamin K along with vitamin D to preclude adverse effects associated with hypervitaminosis D, which include vascular and other soft tissue calcification.

Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7.\nSchurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C.\nBlood. 2007 Apr 15;109(8):3279-83. Epub 2006 Dec 7.\nPMID: 17158229 \nDOI 10.1182/blood-2006-08-040709\n

Dietary intake of vitamin K and risk of prostate cancer in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg).\nNimptsch K, Rohrmann S, Linseisen J.\nAm J Clin Nutr. 2008 Apr;87(4):985-92.\nPMID: 18400723

Tufts University Confirms That Vitamin A Protects Against Vitamin D Toxicity by Curbing Excess Production of Vitamin K-Dependent Proteins Tufts University confirmed my hypothesis that vitamin A protects against vitamin D's induction of renal calcification (kidney stones) by normalizing the production of vitamin K-dependent proteins in December, 2008, without citing my hypothesis or telling me they had confirmed it. I am, of course, very grateful that they thought it significant enough to investigate.

Eicosapentaenoic acid is anti-inflammatory in preventing choroidal neovascularization in mice. Koto T, Nagai N, Mochimaru H, Kurihara T, Izumi-Nagai K, Satofuka S, Shinoda H, Noda K, Ozawa Y, Inoue M, Tsubota K, Oike Y, Ishida S. Invest Ophthalmol Vis Sci. 2007 Sep;48(9):4328-34. PMID: 17724224 DOI:  10.1167/iovs.06-1148

Oral administration of both tetrahydrobiopterin and L-arginine prevents endothelial dysfunction in rats with chronic renal failure. Yamamizu K, Shinozaki K, Ayajiki K, Gemba M, Okamura T. J Cardiovasc Pharmacol. 2007 Mar;49(3):131-9. PMID: 17414224 doi: 10.1097/FJC.0b013e31802f9923

Tissue phylloquinone and menaquinones in rats are affected by age and gender. Huber AM, Davidson KW, O'Brien-Morse ME, Sadowski JA. J Nutr. 1999 May;129(5):1039-44. PMID: 10222397 The results suggest that in extrahepatic tissues, certain menaquinones may be the predominant form of vitamin K. The specific tissue distribution and the general decline of MK-4 and MK-6 in extrahepatic tissues during aging suggest a vitamin K tissue dynamic that is affected not only by diet, but also by gender, age and the specific roles of phylloquinone, MK-4 and MK-6 in metabolism. All of these factors must be taken into account in establishing the nutrient requirement for vitamin K.