Sarah L Booth

..There is also an emerging viewpoint that the biochemical function of vitamin K may extend beyond that of a cofactor for the VKD carboxylation of glutamyl residues (Glus) to carboxylated Glus in VKD proteins...

..Carefully designed studies are required to define the role of osteocalcin and its carboxylated or undercarboxylated forms in the regulation of glucose metabolism in humans...

..Genome-wide association studies (GWAS) provide mechanisms to investigate the genetic contributions to biomarker variability unconstrained by current knowledge of physiological relations...

..Dihydrophylloquinone may be used in models for the study of tissue-specific vitamin K deficiency...

..Vitamin K has been implicated in bone health, primarily in observational studies. However, little is known about the role of phylloquinone supplementation on prevention of bone loss in men and women...

..To understand the impact of vitamin K nutrition on healthy aging it is necessary to assess both the determinants and the adequacy of vitamin K nutritional status of the elderly...

..Although a vitamin E-vitamin K interaction was proposed to underlie this effect, it has not been systematically investigated in adults with normal baseline coagulation status...

..Clinical trials are required to isolate any putative effects of vitamin K on rates of bone loss. The target population in these trials, particularly in regard to estrogen use, may be critical, as suggested by the findings of this study...

..While an encouraging option for management of warfarin therapy, longer-term studies in different patient populations are required...

..Moreover, our findings suggest that the current recommended Adequate Intake levels of vitamin K (90 micro g/d) in women do not support maximal osteocalcin gamma-carboxylation in older women...

..Low dietary vitamin K intake has been associated with an increased risk of hip fracture in men and women. Few data exist on the association between dietary vitamin K intake and bone mineral density (BMD)...

..A preventive role for vitamin K in CAC progression has been proposed on the basis of the properties of matrix Gla protein (MGP) as a vitamin K-dependent calcification inhibitor...

..In vitro and animal studies indicate that high uncarboxylated osteocalcin is associated with reduced insulin resistance. However, associations between osteocalcin and measures of insulin resistance in humans are less clear...

..012), regardless of sex. Adiposity measures and circulating TG did not predict response of any measures. In conclusion, poor vitamin K status can be similarly improved with vitamin K supplementation, regardless of age group or sex...

..Vitamin K modulates cytokines involved in bone turnover, including interleukin-6 (IL-6) and osteoprotegerin in vitro...

..Vitamin K has a potentially beneficial role in insulin resistance, but evidence is limited in humans. We tested the hypothesis that vitamin K supplementation for 36 months will improve insulin resistance in older men and women...

..Despite this caveat, higher plasma dihydrophylloquinone was associated with higher dihydrophylloquinone intake and higher trans fatty acid intake...

..Additional studies are needed to further explore the relationships among body fat, storage of vitamin K in adipose tissue, and implications for vitamin K status and function...

..These data demonstrate that MK-4 is the predominant form of vitamin K in multiple tissues, but there appears to be a tissue-specific regulation for the conversion of PK to MK-4...

..Accumulating evidence suggests that vitamin D is involved in the development of type 2 diabetes (T2D)...

..Despite these caveats, these findings support the use of a FFQ for a relative assessment of vitamin K status in population-based studies...

..The observation that high vitamin K status was associated with lower concentrations of inflammatory markers suggests that a possible protective role for vitamin K in inflammation merits further investigation...

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..The results of this study suggest a role for MGP genetic variants in coronary atherosclerosis among men that is not reflected in serum MGP concentrations...

..Adequate calcium intake is known to protect the skeleton. However, studies that have reported adverse effects of calcium supplementation on vascular events have raised widespread concern...

..Among adults without diabetes, vitamin D status was inversely associated with surrogate fasting measures of insulin resistance. These results suggest that vitamin D status may be an important determinant for type 2 diabetes mellitus...

..Limited evidence suggests that vitamin K may have a beneficial role in glucose homeostasis. No observational data exist on the associations between vitamin K intake and insulin sensitivity...

..Higher intakes of cereal fiber, particularly from whole-grain sources, are associated with lower total percent body fat and percent trunk fat mass in older adults...

..Polymorphisms in genes encoding enzymes involved in vitamin K metabolism may modulate plasma concentrations of phylloquionone and percent carboxylation of osteocalcin...

..Poor diet may affect bone status by displacing nutrients involved in bone health. Dihydrophylloquinone, a form of vitamin K present in foods made with partially hydrogenated fat, is a potential marker of a low-quality dietary pattern...

..The mechanisms by which 9-cis RA and 1,25(OH)(2)D3 alter vitamin K concentrations warrant further investigation...

..Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT...

..13). The LC-APCI/MS method is a sensitive technique for simultaneous determination of both unlabeled and labeled phylloquinone and can be applied to bioavailability studies...

..We aimed to identify common genetic variants affecting vitamin D concentrations and risk of insufficiency...

..Our findings suggest that this animal model may be useful for investigation of the effect of the dietary vitamin K on sulfatide metabolism, myelin structure and behavior functions...

..We therefore evaluated the relationship of MGP concentrations and polymorphisms at the MGP locus to hand OA...

..However, there are emerging data that suggest the efficacy of vitamin K supplementation on bone loss is inconclusive...

..The presence of MK-4 in meat, eggs, and dairy foods could be important as physiologic functions unique to MK-4 are identified...

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..Using this method, urinary menadione was shown to increase in response to 3 years of phylloquinone supplementation. This HPLC method is a sensitive and reproducible way to detect menadione in urine...

..8 hours (n = 3). Deuterated-phylloquinone was not detectable in plasma or TRL fraction at 72 hours. These results suggest rapid uptake and transport of physiologic doses of phylloquinone...

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..Menu planning for patients on warfarin can include a healthy diet including fruits and nuts without compromising the stability of their oral anticoagulation therapy...

..To confirm reports that 25-hydroxyvitamin D (25[OH]D) deficiency is associated with an increased risk of joint space narrowing or cartilage loss in osteoarthritis (OA)...

..Compatible with the long-standing concept that fat tissue is a storage site for vitamin D, fat tissue and serum vitamin D(3) concentrations were positively correlated...

..001). These data emphasize that the use of different approaches for the assessment of vitamin K absorption can result in disparate conclusions...

..abstract:..

..This review summarizes current recommendations for vitamin K in rodent diets relative to our evolving knowledge about this fat-soluble vitamin...

..Further evidence is provided for the notion that calcifications in those regions are associated and that MDCT can be used as a tool for the global assessment of vascular and valvular calcium...

..However, the precise mechanisms of action are not well understood. Further, the physiological consequences of the observed effects of vitamin K on sphingolipid metabolism have not been systematically studied...

..Furthermore, osteophyte growth, seen in osteoarthritis (OA), may be a vitamin K-dependent process. We undertook this study to determine whether vitamin K deficiency is associated with radiographic features of OA...

..699, P < 0.001). We conclude that the urinary excretion of vitamin K metabolites reflects dietary phylloquinone intake and offers the first candidate marker of global vitamin K status...

..Diet composition is one of the factors that may contribute to intraindividual variability in the anticoagulant response to warfarin...

..Nondietary determinants of vitamin K status include apolipoprotein E (apoE) genotype, which may influence vitamin K transport to peripheral tissues...

..The evidence to support this putative role of vitamin K intake in atherosclerosis is reviewed...

..To determine whether orlistat causes fat-soluble vitamin deficiencies in African-American and Caucasian adolescents...

..Matrix Gla protein (MGP) is an inhibitor of calcification in vivo. However, little is known regarding the distribution of circulating MGP and its associations with CHD risk factors or with CAC in humans...

..Rates of bone Ca deposition were lower than typically reported in healthy children, as were indirect markers of bone formation. These alterations in bone turnover contribute to reduced bone mass in girls with CF...

..A growing body of evidence suggests that vitamin D deficiency may adversely affect the cardiovascular system, but data from longitudinal studies are lacking...

..The findings of the proposed study are critical for the interpretation of the epidemiologic and clinical data used to determine optimal intakes at which vitamin K may have a protective role in bone health. ..

..The proposed trial provides a unique opportunity to determine if supplemental vitamin K will reduce age-related bone loss in elderly men and women, above that achieved by supplemental calcium and vitamin D alone. ..

..The proposed ancillary trial provides a unique opportunity to determine if vitamin K supplementation will reduce progression of vascular calcification in older men and women...

..Results of the studies proposed could lead to effective intervention programs that reduce bone loss resulting in a decreased risk and incidence of osteoporosis. ..