Group items tagged

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

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

Prevalence of Vitamin D inadequacy among postmenopausal North American women receiving osteoporosis therapy. Holick MF, Siris ES, Binkley N, Beard MK, Khan A, Katzer JT, Petruschke RA, Chen E, de Papp AE. J Clin Endocrinol Metab. 2005 Jun;90(6):3215-24. Epub 2005 Mar 29. PMID: 15797954 doi:10.1210/jc.2004-2364 Conclusions: More than half of North American women receiving therapy to treat or prevent osteoporosis have vitamin D inadequacy, underscoring the need for improved physician and public education regarding optimization of vitamin D status in this population.

Conjugated linoleic acid promotes human adipocyte insulin resistance through NFkappaB-dependent cytokine production. Chung S, Brown JM, Provo JN, Hopkins R, McIntosh MK. J Biol Chem. 2005 Nov 18;280(46):38445-56. Epub 2005 Sep 9. PMID: 16155293 doi: 10.1074/jbc.M508159200 Collectively, these data demonstrate for the first time that trans-10, cis-12 CLA promotes NFkappaB activation and subsequent induction of IL-6, which are at least in part responsible for trans-10, cis-12 CLA-mediated suppression of peroxisome proliferator-activated receptor gamma target gene expression and insulin sensitivity in mature human adipocytes. In summary, our in vitro data demonstrate that a physiological level of trans-10, cis-12 CLA activates NFκB- and ERK1/2-dependent cytokine production, which together suppress PPARγ and Glut4 levels and lead to impaired glucose uptake. Studies are currently under way examining 1) how CLA regulates PPARγ and the expression of its target genes, 2) the specific signaling role of SV cells and adipocytes in mediating the TG-lowering actions of CLA, and 3) the CLA-induced, upstream signal that activates NFκB and ERK1/2.