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Vitamin K—Keeps Calcium Out of Your Arteries and In Your Bones

Vitamin K has recently received a lot of attention from health and nutrition researchers. A long forgotten and misunderstood nutrient, vitamin K is making a comeback and its importance to human health is rapidly being unveiled.

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From assisting the development of bone, to preventing arterial calcification, to fighting off cancer and inflammation, vitamin K is the new hot nutrient and for good reason.

What is vitamin K?

Originally identified as a fat-soluble nutrient required for normal blood coagulation, vitamin K is actually a family of similar compounds, which recent research reveals are also necessary for integrating calcium into bone and preventing its deposit within blood vessels. The latest research also indicates vitamin K possesses significant anti-cancer and anti-inflammatory actions.

In nature, vitamin K is found in the forms of vitamin K1 (phylloquinone) and several different types of vitamin K2 (menaquinones):

K1, which is involved in photosynthesis, is produced by plants and algae, its highest concentrations found in green leafy vegetables. Primary dietary sources of K1 are leafy greens, such as broccoli, kale, and Swiss chard, and plant oils, such as canola and soybean oil.

K2 is produced by bacteria and also via the conversion of K1 to K2 by beneficial bacteria in the intestines of animals, including humans. Natto (fermented soybeans) is the richest dietary source of vitamin K2. Dairy products (milk, butter, cottage cheese, cheese) and egg yolk also provide small amounts.

K2 is more potent and has the widest range of activity. Far more active than K1 in both bone formation and reduction of bone loss, K2 is a 15-fold more powerful antioxidant than K1, and is also the form in which vitamin K has been found to protect against arterial calcification and the oxidation (free radical damage) of LDL cholesterol.123


 


Finally, K2 occurs in numerous forms that vary in their activity. Vitamin K2 can have a side chain between 4 and 9 units long. This side chain has a great effect on the bioavailability of vitamin K. Shorter chain length results in shorter half-life within the body, thus limiting our body’s ability to utilize vitamin K. Both vitamin K1 and vitamin K2 in the form of menaquinone-4 have very short half-lives in the body, while longer chain forms of vitamin K2, such as menaquinone-7, have dramatically longer half-lives and much higher bioactivity. Because recent research has shown that vitamin K2, in the form of menaquinone-7, is the most potent and longest acting form of vitamin K2, many researchers now consider it to be the most important dietary form of vitamin K for protecting the cardiovascular system and promoting bone health.4

What are the mechanisms behind vitamin K’s functions in the body?

Vitamin K is needed for the “carboxylation” of Gla-proteins. Carboxylation activates these proteins, which perform a number of essential activities throughout the body, including regulating blood clotting and calcium.5

K1 is the form used in the liver to activate clotting factors, while K2 is the form used in the rest of the body to activate other vitamin K-dependent Gla-proteins, including osteocalcin, which is essential for bone health, and matrix-Gla protein, which prevents calcification of blood vessels and organs, including the heart and kidneys.

Vitamin K2 is also found in high concentrations in the brain, where it contributes to the production of myelin (a fatty substance that covers and protects nerves), protects brain cells against free radical injury, and is thought to play a role in the development of the central nervous system.67

K2 also activates a number of other proteins that regulate bone metabolism and inhibit the growth of cancer cells.89

Balancing blood clotting

Blood must flow freely through our cardiovascular system, unless injury causes a breach in a blood vessel, in which case, blood must clot rapidly to prevent excessive, potentially fatal blood loss. If clots form too readily, however, blood vessels can become blocked, cutting off the delivery of oxygen and nutrients, which rapidly results in tissue and organ death.

Vitamin K-dependent Gla-proteins are responsible for maintaining the delicate balance needed between coagulation and anticoagulation. In a system called the “coagulation cascade,” procoagulant vitamin K-dependent proteins (including prothrombin and the coagulation factors) create a dense mesh of fibrin that traps platelets and stops the loss of blood. At the same time, their anti-coagulant partners inhibit the process, preventing excessive clotting and rapidly clearing clots once they are no longer necessary.

Keeping calcium out of arteries

Cardiovascular disease is not just about cholesterol, which, if oxidized, can form visible plaques on the innermost wall of the arteries, a condition called atherosclerosis. Just as lethal is arteriosclerosis; hardening of the arteries due to calcium deposits.

The elasticity that characterizes a healthy artery is what enables it to accommodate increases in blood flow. Add enough calcium and that pliability is lost; the artery can’t expand and contract, so blood pressure rises.

Sudden death from heart attack is even more highly correlated with calcification of the aorta than cholesterol. In Framingham study research, aortic calcification was associated with double the risk of death from cardiovascular disease in men and women younger than 65, even after other risk factors (e.g., cholesterol) were taken into account. In men younger than 35, calcification of the aorta increased risk of sudden coronary death 7-fold.1011

In other research involving more than 100,000 men and women in California, aortic calcification increased risk of coronary heart disease 127% in men and 122% in women. Among women, it also increased risk of stroke 146%.12

A high coronary artery calcium score on electron beam tomography has been found to be a better predictor of mortality than age. A calcium score of less than 10 confers a reduction in functional age by 10 years in subjects older than 70, while a calcium score of >400 adds as much as 30 years of functional aging to younger patients.131415

Fortunately, vitamin K-dependent proteins have been shown to inhibit calcification in the heart and arteries, and also in the kidneys, where K2 prevents the calcification that typically accompanies dialysis and diabetes. In women whose diets provide the most vitamin K2 have significantly less breast calcification compared to those whose diets provide the least.16

How does vitamin K prevent arterial calcification and promote blood vessel elasticity?

One of the vitamin K-dependent proteins, matrix Gla-protein (MGP) is the strongest inhibitor of tissue calcification presently known. MGP’s importance for blood vessel health was first demonstrated in animals bred to be MGP-deficient, all of which died of massive arterial calcification within 6–8 weeks after birth.17 MGP is produced by small muscle cells in our blood vessels where—once activated by vitamin K—it prevents calcium deposits.18

K2 also helps promote blood vessel elasticity by safeguarding elastin, the protein primarily responsible for the elasticity of the arterial wall. Existing elastin is damaged and new production is inhibited by calcium deposition.19

In the Rotterdam study, a massive European clinical trial following 4,807 subjects aged at least 55 over a 7-10 year period, researchers found that K2, but not K1, significantly reduced risk of cardiovascular disease by 57%, death from all causes by 26%, and severe aortic calcification by 52%. K1 provided no significant cardiovascular protection.20

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References

  1. Thijssen HH, Drittij-Reijnders MJ. Vitamin K status in human tissues: tissue-specific accumulation of phylloquinone and menaquinone-4. Br J Nutr. 1996 Jan;75(1):121-7.

  2. Schurgers LJ, Dissel PE, Spronk HM, et al. Role of vitamin K and vitamin K-dependent proteins in vascular calcification. Z Kardiol. 2001;90 Suppl 3:57-63.

  3. Jono S, Ikari Y, Vermeer C, et al. Matrix Gla protein is associated with coronary artery calcification as assessed by electron-beam computed tomography. Thromb Haemost. 2004 Apr;91(4):790-4.

  4. Schurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood. 2007 Apr 15;109(8):3279-83. Epub 2006 Dec 7.

  5. Uotila L. The metabolic functions and mechanism of action of vitamin K. Scand J Clin Lab Invest Suppl. 1990;201:109-17.

  6. Li J, Lin JC, Wang H, Peterson JW, Furie BC, Furie B, Booth SL, Volpe JJ, Rosenberg PA. Novel role of vitamin k in preventing oxidative injury to developing oligodendrocytes and neurons. J Neurosci. 2003 Jul 2;23(13):5816-26.

  7. Kaneki M, Hosoi T, Ouchi Y, Orimo H. Pleiotropic actions of vitamin K: protector of bone health and beyond? Nutrition. 2006 Jul-Aug;22(7-8):845-52.

  8. Otsuka M, Kato N, Ichimura T, et al. Vitamin K2 binds 17β-hydroxysteroid dehydrogenase 4 and modulates estrogen metabolism. Life Sci 2005 Apr 8;76(21):2473-82.

  9. Plaza SM, Lamson DW. The anticancer effects of vitamin K. Altern Med Rev. 2003 Aug 8(3):303-318.

  10. Witteman JC, Kannel WB, Wolf PA, et al. Aortic calcified plaques and cardiovascular disease (the Framingham Study). Am J Cardiol. 1990 Nov 1;66(15):1060-4.

  11. Pohle K, Ropers D, Mäffert R, et al. Coronary calcifications in young patients with first, unheralded myocardial infarction: a risk factor matched analysis by electron beam tomography. Heart. 2003 Jun;89(6):625-8. 

  12. Iribarren C, Sidney S, Sternfeld B, et al. Calcification of the aortic arch: risk factors and association with coronary heart disease, stroke, and peripheral vascular disease. JAMA. 2000 Jun 7;283(21):2810-5.

  13. Shaw LJ, Raggi P, Berman DS, Callister TQ. Coronary artery calcium as a measure of biologic age. Atherosclerosis. 2006 Sep;188(1):112-9.

  14. Church TS, Levine BD, McGuire DK, et al. Coronary artery calcium score, risk factors, and incident coronary heart disease events. Atherosclerosis. 2007 Jan;190(1):224-31.

  15. Taylor AJ, Bindeman J, Feuerstein I, et al. Coronary calcium independently predicts incident premature coronary heart disease over measured cardiovascular risk factors: mean three-year outcomes in the Prospective Army Coronary Calcium (PACC) project. J Am Coll Cardiol. 2005 Sep 6;46(5):807-14.

  16. Seyama Y, Wachi H. Atherosclerosis and matrix dystrophy. J Athero Thromb 2004;11(5):236-45.

  17. Cranenburg EC, Schurgers LJ, Vermeer C. Vitamin K: The coagulation vitamin that became omnipotent. Thromb Haemost. 2007 Jul;98(1):120-5.

  18. Demer LL, Tintut Y, Parhami F. Novel mechanisms in accelerated vascular calcification in renal disease patients. Curr Opin Nephrol Hypertens. 2002 Jul;11(4):437-43.

  19. Seyama Y, Wachi H. Atherosclerosis and matrix dystrophy. J Athero Thromb 2004;11(5):236-45.

  20. Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004 Nov;134(11):3100-5.

  21. Bügel S. Vitamin K and bone health. Proc Nutr Soc. 2003 Nov;62(4):839-43.

  22. Yamaguchi M, Sugimoto E, Hachiya S. Stimulatory effect of menaquinone-7 (vitamin K2) on osteoblastic bone formation in vitro. Mol Cell Biochem. 2001 Jul;223(1-2):131-7.

  23. Yamaguchi M, Uchiyama S, Tsukamoto Y. Inhibitory effect of menaquinone-7 (vitamin K2) on the bone-resorbing factors-induced bone resorption in elderly female rat femoral tissues in vitro. Mol Cell Biochem. 2003 Mar;245(1-2):115-20.

  24. Bitensky L, Hart JP, Catterall A, et al. Circulating vitamin K levels in patients with fractures. J Bone Joint Surg Br. 1988 Aug;70(4):663-4.

  25. Berkner KL, Runge KW. The physiology of vitamin K nutriture and vitamin K-dependent protein function in atherosclerosis. J Thromb Haemost. 2004 Dec;2(12):2118-32.

  26. Braam LA, Hoeks AP, Brouns F, et al. Beneficial effects of vitamins D and K on the elastic properties of the vessel wall in postmenopausal women: a follow-up study. Thromb Haemost. 2004 Feb;91(2):373-80.

  27. Adams J, Pepping J. Vitamin K in the treatment and prevention of osteoporosis and arterial calcification. Am J Health Syst Pharm. 2005 Aug 1;62(15):1574-81.

  28. Purwosunu Y, Muharram , Rachman IA, Reksoprodjo S, Sekizawa A. Vitamin K2 treatment for postmenopausal osteoporosis in Indonesia. J Obstet Gynaecol Res. 2006 Apr;32(2):230-4.

  29. Hart JP, Catterall A, Dodds RA, et al. Circulating vitamin K1 levels in fractured neck of femur. Lancet. 1984 Aug 4;2(8397):283.

  30. Hodges SJ, Pilkington MJ, Stamp TC, et al. Depressed levels of circulating menaquinones in patients with osteoporotic fractures of the spine and femoral neck. Bone. 1991;12(6):387-9.

  31. Booth SL, Tucker KL, Chen H, et al. Dietary vitamin K intakes are associated with hip fracture but not with bone mineral density in elderly men and women. Am J Clin Nutr. 2000 May;71(5):1201-8.

  32. Cockayne S, Adamson J, Lanham-New S, et al. Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2006 Jun 26;166(12):1256-61.

  33. Shiraki M, Shiraki Y, Aoki C, et al. Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis. J Bone Miner Res. 2000 Mar;15(3):515-21.

  34. Masterjohn C. Vitamin D toxicity redefined: vitamin K and the molecular mechanism. Med Hypotheses. 2007;68(5):1026-34. Epub 2006 Dec 4.

  35. Iwamoto J, Takeda T, Ichimura S. Effect of combined administration of vitamin D3 and vitamin K2 on bone mineral density of the lumbar spine in postmenopausal women with osteoporosis. J Orthop Sci. 2000;5(6):546-51.

  36. Iwamoto J, Takeda T, Ichimura S. Treatment with vitamin D3 and/or vitamin K2 for postmenopausal osteoporosis. Keio J Med. 2003 Sep;52(3):147-50.

  37. Ushiroyama T, Ikeda A, Ueki M. Effect of continuous combined therapy with vitamin K(2) and vitamin D(3) on bone mineral density and coagulofibrinolysis function in postmenopausal women. Maturitas. 2002 Mar 25;41(3):211-21.

  38. Iwamoto J, Takeda T, Ichimura S. Combined treatment with vitamin K2 and bisphosphonate in postmenopausal women with osteoporosis. Yonsei Med J. 2003 Oct 30;44(5):751-6.

  39. Adams J, Pepping J. Vitamin K in the treatment and prevention of osteoporosis and arterial calcification. Am J Health Syst Pharm. 2005 Aug 1;62(15):1574-81.

  40. Booth SL, Broe KE, Peterson JW, et al. Associations between vitamin K biochemical measures and bone mineral density in men and women. J Clin Endocrinol Metab. 2004 Oct;89(10):4904-9.

  41. Knapen MH, Schurgers LJ, Vermeer C. Vitamin K(2) supplementation improves hip bone geometry and bone strength indices in postmenopausal women. Osteoporos Int. 2007 Jul;18(7):963-72. Epub 2007 Feb 8.

  42. Shankar SL, O’Guin K, Kim M, et al. Gas6/Axl signaling activates the phosphatidylinositol 3-kinase/Akt1 survival pathway to protect oligodendrocytes from tumor necrosis factor alpha-induced apoptosis. J Neurosci. 2006 May 24;26(21):5638-48.

  43. Nouso K, Uematsu S, Shiraga K, et al. Regression of hepatocellular carcinoma during vitamin K administration. World J Gastroenterol. 2005 Nov 14;11(42):6722-4.

  44. Habu D, Shiomi S, Tamori A, et al. Role of vitamin K2 in the development of hepatocellular carcinoma in women with viral cirrhosis of the liver. JAMA. 2004 Jul 21;292(3):358-61.

  45. Vervoort LM, Ronden JE, Thijssen HH. The potent antioxidant activity of the vitamin K cycle in microsomal lipid peroxidation. Biochem Pharmacol. 1997 Oct 15;54(8):871-6.

  46. Li J, Lin JC, Wang H, Peterson JW, et al. Novel role of vitamin k in preventing oxidative injury to developing oligodendrocytes and neurons. J Neurosci. 2003 Jul 2;23(13):5816-26.

  47. Tsugawa N, Shiraki M, Suhara Y, et al. Vitamin K status of healthy Japanese women: age-related vitamin K requirement for gamma-carboxylation of osteocalcin. Am J Clin Nutr. 2006 Feb;83(2):380-6.

  48. Uotila L. The metabolic functions and mechanism of action of vitamin K. Scand J Clin Lab Invest Suppl. 1990;201:109-17.

  49. Koos R, Mahnken AH, Mühlenbruch G. Relation of oral anticoagulation to cardiac valvular and coronary calcium assessed by multislice spiral computed tomography. Am J Cardiol. 2005 Sep 15;96(6):747-9.

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