Group items tagged

High dietary menaquinone intake is associated with reduced coronary calcification.\nBeulens JW, Bots ML, Atsma F, Bartelink ML, Prokop M, Geleijnse JM, Witteman JC, Grobbee DE, van der Schouw YT.\nAtherosclerosis. 2008 Jul 19. [Epub ahead of print]\nPMID: 18722618 \ndoi:10.1016/j.atherosclerosis.2008.07.010 \n

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

Mechanisms underlying the biphasic effect of vitamin K1 (phylloquinone) on arterial blood pressure.\nTirapelli CR, Resstel LB, de Oliveira AM, Corrêa FM.\nJ Pharm Pharmacol. 2008 Jul;60(7):889-93.\nPMID: 18549675 \nDOI: 10.1211/jpp.60.7.0010\n

A study recently published by the European Prospective Investigation into Cancer and Nutrition (EPIC) has revealed that increased intake of vitamin K2 may reduce the risk of prostate cancer by 35 percent. The authors point out that the benefits of K2 were most pronounced for advanced prostate cancer, and, importantly, that vitamin K1 did not offer any prostate benefits.

A high menaquinone reduces the incidence of coronary heart disease in women.\nGast GC, de Roos NM, Sluijs I, Bots ML, Beulens JW, Geleijnse JM, Witteman JC, Grobbee DE, Peeters PH, van der Schouw YT.\nNutr Metab Cardiovasc Dis. 2009 Jan 27. [Epub ahead of print]\nPMID: 19179058 \ndoi: 10.1016/j.numecd.2008.10.004\n

Increased intakes of vitamin K2, but not vitamin K1, may decrease the risk of coronary heart disease in postmenopausal women, says a new study.\nFor every 10 microgram increase in the amount of vitamin K2 consumed, researchers from the Netherlands report a 9 per cent reduction in the risk of developing coronary heart disease (CHD).

Determination of Phylloquinone and Menaquinones in Foods by HPLC\n\nTerhi Koivu-Tikkanen\n\nAcademic Dissertation, January 2001. \nUniversity of Helsinki, Faculty of Agriculture and Forestry, \nDepartment of Applied Chemistry and Microbiology

Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Cockayne S, Adamson J, Lanham-New S, Shearer MJ, Gilbody S, Torgerson DJ. Arch Intern Med. 2006 Jun 26;166(12):1256-61. Review. PMID: 16801507 Conclusions This systematic review suggests that supplementation with phytonadione and menaquinone-4 reduces bone loss. In the case of the latter, there is a strong effect on incident fractures among Japanese patients.

Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial. Cheung AM, Tile L, Lee Y, Tomlinson G, Hawker G, Scher J, Hu H, Vieth R, Thompson L, Jamal S, Josse R. PLoS Med. 2008 Oct 14;5(10):e196. Erratum in: PLoS Med. 2008 Dec;5(12):e247. PMID: 18922041 CONCLUSIONS: Daily 5 mg of vitamin K1 supplementation for 2 to 4 y does not protect against age-related decline in BMD, but may protect against fractures and cancers in postmenopausal women with osteopenia. More studies are needed to further examine the effect of vitamin K on fractures and cancers. Trial registration: ClinicalTrials.gov (#NCT00150969) and Current Controlled Trials (#ISRCTN61708241)

Menaquinone-4 concentration is correlated with sphingolipid concentrations in rat brain. Carrié I, Portoukalian J, Vicaretti R, Rochford J, Potvin S, Ferland G. J Nutr. 2004 Jan;134(1):167-72. PMID: 14704312

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.

Age and dietary form of vitamin K affect menaquinone-4 concentrations in male Fischer 344 rats. Booth SL, Peterson JW, Smith D, Shea MK, Chamberland J, Crivello N. J Nutr. 2008 Mar;138(3):492-6. PMID: 18287355 These data suggest that dihydrophylloquinone, which differs from phylloquinone in its side phytyl chain, is absorbed but its intake results in less MK-4 in certain tissues. Dihydrophylloquinone may be used in models for the study of tissue-specific vitamin K deficiency

Conversion of phylloquinone (Vitamin K1) into menaquinone-4 (Vitamin K2) in mice: two possible routes for menaquinone-4 accumulation in cerebra of mice.\nOkano T, Shimomura Y, Yamane M, Suhara Y, Kamao M, Sugiura M, Nakagawa K.\nJ Biol Chem. 2008 Apr 25;283(17):11270-9. Epub 2007 Dec 14. \nPMID: 18083713 \ndoi: 10.1074/jbc.M702971200 \n\nOur results suggest that cerebral menaquinone-4 originates from phylloquinone intake and that there are two routes of accumulation, one is the release of menadione from phylloquinone in the intestine followed by the prenylation of menadione into menaquinone-4 in tissues, and another is cleavage and prenylation within the cerebrum.

Conversion of dietary phylloquinone to tissue menaquinone-4 in rats is not dependent on gut bacteria. Davidson RT, Foley AL, Engelke JA, Suttie JW. J Nutr. 1998 Feb;128(2):220-3. PMID: 9446847 These data offer conclusive proof that the tissue-specific formation of MK-4 from K is a metabolic transformation that does not require bacterial transformation to menadione as an intermediate in the process

[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

Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats. Schurgers LJ, Spronk HM, Soute BA, Schiffers PM, DeMey JG, Vermeer C. Blood. 2007 Apr 1;109(7):2823-31. PMID: 17138823 DOI 10.1182/blood-2006-07-035345. This is the first study in rats demonstrating that AC and the resulting decreased arterial distensibility are reversible by high-VK intake