RESUMEN
Following the work of Avenell et al. that has raised concerns about the integrity of the Yamaguchi Osteoporosis Prevention Study (YOPS) conducted by Ishida and Kawai we issue here an adjustment to all meta-analysis estimates that contained this work within our systematic review.
RESUMEN
Vitamin K may affect bone mineral density and fracture incidence. Since publication of a previous systematic review the integrity of some of the previous evidence has been questioned and further trials have been published. Therefore an update to the systematic review was required. INTRODUCTION: This systematic review was designed to assess the effectiveness of oral vitamin K supplementation for increasing bone mineral density and reducing fractures in adults. METHODS: MEDLINE, EMBASE, CENTRAL, CINAHL, clinicaltrials.gov, and WHO-ICTRP were searched for eligible trials. Randomised controlled trials assessing oral vitamin K supplementation that assessed bone mineral density or fractures in adult populations were included. A total of 36 studies were identified. Two independent reviewers extracted data using a piloted extraction form. RESULTS: For post-menopausal or osteoporotic patients, meta-analysis showed that the odds of any clinical fracture were lower for vitamin K compared to controls (OR, 0.72, 95%CI 0.55 to 0.95). Restricting the analysis to low risk of bias trials reduced the OR to 0.76 (95%CI, 0.58 to 1.01). There was no difference in vertebral fractures between the groups (OR 0.96, 95%CI 0.83 to 1.11). In the bone mineral density meta-analysis, percentage change from baseline at the lumbar spine was higher at 1 year (MD 0.93, 95%, CI - 0.02 to 1.89) and 2 years (MD 1.63%, 95%CI 0.10 to 3.16) for vitamin K compared to controls; however, removing trials at high risk of bias tended to result in smaller differences that were not statistically significant. At 6 months, it was higher in the hip (MD 0.42%, 95%CI 0.01 to 0.83) and femur (MD 0.29%, 95%CI 0.17 to 0.42). There was no significant difference at other anatomical sites. CONCLUSIONS: For post-menopausal or osteoporotic patients, there is no evidence that vitamin K affects bone mineral density or vertebral fractures; it may reduce clinical fractures; however, the evidence is insufficient to confirm this. There are too few trials to draw conclusions for other patient groups.
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Densidad Ósea/efectos de los fármacos , Fracturas Osteoporóticas/prevención & control , Vitamina K/farmacología , Suplementos Dietéticos , Humanos , Osteoporosis/tratamiento farmacológico , Osteoporosis/fisiopatología , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Fracturas de la Columna Vertebral/prevención & control , Vitamina K/uso terapéuticoRESUMEN
BACKGROUND AND OBJECTIVE: Despite the worldwide use of vitamin K antagonists (VKAs), there is limited knowledge of the influence of dietary vitamin K on anticoagulation control. In view of the increasing nutraceutical availability of menaquinone-7 (MK-7; vitamin K2 ) and its promotion for bone and cardiovascular health, it is important to determine the posology for the interference of supplemental MK-7 with VKA therapy. PATIENTS: Eighteen healthy men and women were anticoagulated for 4 weeks with acenocoumarol, and 15 of them attained a target International Normalized Ratio (INR) of 2.0. In the six subsequent weeks, subjects were given increasing doses of MK-7 (10, 20 and 45 µg day(-1) ) while continuing acenocoumarol treatment at established individual doses. RESULTS: Apart from the INR, acenocoumarol treatment significantly increased the levels of uncarboxylated factor II (ucFII), uncarboxylated osteocalcin (ucOC), and desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP), and decreased endogenous thrombin generation (ETP). A daily intake of 45 µg of MK-7 significantly decreased the group mean values of both the INR and ucFII by ~ 40%. Daily intakes of 10 and 20 µg of MK-7 were independently judged by two hematologists to cause a clinically relevant lowering of the INR in at least 40% and 60% of subjects, respectively, and to significantly increase ETP by ~ 20% and ~ 30%, respectively. Circulating ucOC and dp-ucMGP were not affected by MK-7 intake. CONCLUSIONS: MK-7 supplementation at doses as low as 10 µg (lower than the usual retail dose of 45 µg) significantly influenced anticoagulation sensitivity in some individuals. Hence, the use of MK-7 supplements needs to be avoided in patients receiving VKA therapy.
Asunto(s)
Anticoagulantes/administración & dosificación , Anticoagulantes/uso terapéutico , Suplementos Dietéticos , Vitamina K 2/análogos & derivados , Acenocumarol/administración & dosificación , Administración Oral , Adolescente , Adulto , Antropometría , Coagulación Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Voluntarios Sanos , Hemostáticos/uso terapéutico , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Trombina/química , Vitamina K 2/uso terapéutico , Adulto JovenAsunto(s)
Retículo Endoplásmico/metabolismo , Oxigenasas de Función Mixta/genética , Warfarina/farmacología , Administración Oral , Adolescente , Adulto , Anciano , Anticoagulantes/farmacología , Fibrilación Atrial/sangre , Fibrilación Atrial/terapia , Ligasas de Carbono-Carbono/metabolismo , Femenino , Humanos , Masculino , Fenotipo , Vitamina D/metabolismo , Vitamina K Epóxido ReductasasRESUMEN
Vascular calcification (VC) is highly prevalent in CKD and leads to increased vascular stiffness and cardiovascular disease (CVD). Non-traditional cardiovascular risk factors include abnormal bone turnover and/or dysregulation of the calcification inhibitors, although their relative contribution remains unclear. We investigated the association between bone turnover, the calcification inhibitors (matrix gla protein; MGP and Fetuin-A), and the phosphate regulating hormone; fibroblast growth factor-23 (FGF-23) and arterial stiffness in pre-dialysis CKD patients. One hundred and forty-five patients with CKD stages 1-4 (74 M, 71 F) aged (mean [SD]) 53 [14] years were studied. Bone turnover markers (bone-specific alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase (TRACP)) and MGP, Fetuin-A and FGF-23 were determined. BMD was measured at the lumbar spine (LS), femoral neck (FN), forearm (FARM) and total hip (TH). Arterial stiffness was assessed by contour analysis of digital volume pulse (SI(DVP)). There was a significant positive correlation between TRACP:BALP ratio and SI(DVP) ( r=0.19, p=0.023). Following multi-linear regression analysis, significant associations were seen between serum BALP (p=0.037), TRACP (p=0.009) and TRACP:BALP ratio (p=0.001) and SI(DVP) independently of traditional CVD risk factors. No significant relationship between SI(DVP) and MGP, Fetuin-A and FGF-23 was observed. A significant negative correlation was seen between BMD at the FARM and SI(DVP) in CKD stage 4 (r=-0.35, p=0.024). The association remained significant following correction for age, gender and cardiovascular risk factors (p=0.029). Our data suggest a link between imbalances in bone turnover and arterial stiffness in pre-dialysis CKD. Longitudinal studies are needed to evaluate the clinical usefulness of these bone turnover markers as predictors of CVD in CKD.
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Arterias/fisiopatología , Remodelación Ósea/fisiología , Fallo Renal Crónico/fisiopatología , Diálisis Renal , Fosfatasa Ácida/metabolismo , Fosfatasa Alcalina/metabolismo , Biomarcadores/metabolismo , Densidad Ósea/fisiología , Demografía , Femenino , Factor-23 de Crecimiento de Fibroblastos , Humanos , Isoenzimas/metabolismo , Masculino , Persona de Mediana Edad , Análisis de Regresión , Fosfatasa Ácida TartratorresistenteRESUMEN
BACKGROUND: Vitamin K epoxide reductase subunit 1 (VKORC1) is the molecular target of coumarin anticoagulants and mutations in VKORC1 have been identified previously in individuals who required high warfarin doses. OBJECTIVE: Detailed characterization of the relationship between variation in VKORC1 and the warfarin resistance phenotype. PATIENTS AND METHODS: Serum warfarin concentration and coagulation parameters were determined in 289 subjects who required warfarin doses >20 mg day(-1). The VKORC1 sequence was studied in selected study subjects. RESULTS: Twenty-eight out of 289 (10%) subjects had serum warfarin >2.3 mg L(-1) during stable therapeutic anticoagulation indicating pharmacodynamic warfarin resistance. Detailed analysis of 15 subjects from this group showed that eight out of 15 (53%) had nucleotide substitutions in VKORC1 predictive of p.V66M, p.L128R, p.V54L or p.D36Y. VKORC1 was normal in the remaining seven out of 15 (47%) subjects and in nine out of nine (100%) subjects with high warfarin dose requirement not caused by pharmacodynamic resistance. At referral, subjects with VKORC1 mutations received a median warfarin dose of 32 mg day(-1) (range 22-55) and had a median serum warfarin concentration of 4.6 mg L(-1) (range 2.6-9.0). VKORC1 substitutions were associated with a requirement for high warfarin doses but not with adverse clinical events. Family members with VKORC1 nucleotide substitutions and not receiving warfarin had undetectable PIVKA-II and K(1) epoxide (K(1)O). CONCLUSIONS: Nucleotide variations in VKORC1 are a common cause of pharmacodynamic warfarin resistance but are not associated with adverse outcome during anticoagulation. Mutations associated with warfarin resistance do not cause a discernible defect in VKORC1 reductase function.
Asunto(s)
Resistencia a Medicamentos , Oxigenasas de Función Mixta/genética , Polimorfismo de Nucleótido Simple , Warfarina/farmacocinética , Biomarcadores/sangre , Análisis Mutacional de ADN , Humanos , Oxidorreductasas , Farmacocinética , Precursores de Proteínas/sangre , Protrombina , Vitamina K Epóxido Reductasas , Warfarina/sangreRESUMEN
BACKGROUND: Many patients with advanced cancer are malnourished. Anorexia is common, as is the use of chemotherapy, which may cause nausea and poor appetite. Ten per cent of these patients experience haemorrhagic events. AIM: Since vitamin K deficiency (VKD) causes bleeding, to establish the prevalence of VKD in patients with advanced cancer receiving palliative care. METHODS: Serum concentrations of vitamin K(1) and undercarboxylated factor II (PIVKA-II) were determined in 46 (17 male/29 female) inpatients aged 26-85 (mean 58) years. INR and liver function tests (bilirubin, ALT, GGT and ALP) were also performed. RESULTS: Vitamin K(1) was below the lower limit of the reference range (0.33 nmol/l) in 22% of patients. 78% of patients had some degree of functional VKD indicated by raised (>0.2 AU/ml) PIVKA-II. Six patients (13%) had a prolonged INR, all of whom had raised PIVKA-II and GGT; 4 also had vitamin K(1) <0.33 nmol/l. Three patients (6.5%) had clinically significant VKD characterised by INR >1.5, PIVKA-II >10 AU/ml, and undetectable vitamin K(1). CONCLUSIONS: Patients with advanced cancer are prone to VKD which, while usually subclinical, may develop to a clinically relevant prolongation of the INR. Serum measurements of vitamin K(1) and PIVKA-II can be used to detect VKD and monitor vitamin K status before an increased risk of bleeding develops.
Asunto(s)
Trastornos Hemostáticos/etiología , Neoplasias/complicaciones , Cuidados Paliativos , Deficiencia de Vitamina K/etiología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Femenino , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Neoplasias/sangre , Precursores de Proteínas/sangre , Protrombina , Vitamina K 1/sangre , Deficiencia de Vitamina K/sangre , Deficiencia de Vitamina K/diagnósticoRESUMEN
CONTEXT: Little is known of associations between hip geometry and skeletal regulators. This is important because geometry is a determinant of both hip function and resistance to fracture. OBJECTIVE: We aimed to determine the effects of sex hormone status and other candidate regulators on hip geometry and strength. SUBJECTS AND METHODS: A random sample of 351 women aged 67-79 had two to four hip dual-energy x-ray absorptiometry scans performed over 8 yr of follow-up. Hip structural analysis software was used to measure subperiosteal diameter (PD) and the distance from the center of mass to the lateral cortical margin (d-lat) on three 5-mm-thick cross-sectional regions: narrow neck, intertrochanter, and shaft. Section modulus (Z), bone mineral density (grams per centimeter squared), and an index of bone mineral content (cross-sectional area) were calculated as estimators of bone strength. Serum analytes measured at baseline included SHBG, estradiol, PTH, creatinine, albumin, vitamin D metabolites, and glutamate- and gamma-carboxyglutamate-osteocalcin (OC). A linear mixed model was used to model associations with predictor variables, including testing whether the predictors significantly modified the effect of aging. RESULTS: Aging was associated with increasing PD and d-lat, and higher baseline SHBG significantly modified this effect, in the case of PD, increasing the rates of change at the narrow neck region by 19% for SHBG level 2 sd higher than population mean (P = 0.026). Higher baseline creatinine was independently associated with faster increases in PD and d-lat with aging (P < 0.041). Z declined faster with aging if baseline PTH was higher, and higher albumin had a contrary effect. Z was positively associated with free estradiol and inversely associated with SHBG and glutamate-OC. CONCLUSION: These results show large effects of SHBG on the regulation of proximal femur expansion and bending resistance, probably acting as a surrogate for low bioavailable estrogen. Potentially important effects for fracture resistance in old age were also revealed for PTH, markers related to renal function and the nutritional markers albumin and undercarboxylated OC.
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Envejecimiento/metabolismo , Fémur/anatomía & histología , Hormonas Esteroides Gonadales/sangre , Anciano , Densidad Ósea , Femenino , Humanos , Osteocalcina/sangre , Hormona Paratiroidea/sangre , Globulina de Unión a Hormona Sexual/análisisRESUMEN
OBJECTIVE: To investigate plasma osteocalcin gamma-carboxylation and its relationship to plasma phylloquinone concentration and apolipoprotein E (apoE) genotype in women from three ethnic groups with differing osteoporotic fracture risk. DESIGN AND SUBJECTS: Fasted blood samples were collected from postmenopausal Gambian (n=50), British (n=31) and Chinese women (n=23), and 11 premenopausal women in each group from three cross-sectional studies. RESULTS: After adjustment for total osteocalcin, plasma undercarboxylated osteocalcin (adjusted ucOC) was lowest in Chinese and highest in British women postmenopause (British vs Chinese 103% higher, P<0.0001; Gambian vs Chinese 66% higher, P<0.01). No differences were observed premenopause. Within each ethnic group, adjusted ucOC was similar pre- and postmenopause. Postmenopause, plasma phylloquinone was higher in Chinese women (1.0 ng/ml) than in British (0.31 ng/ml) and Gambian women (0.36 ng/ml) (P<0.0001). Premenopause, plasma phylloquinone was higher in Gambian and Chinese women (0.6 ng/ml) than in British women (0.3 ng/ml; P=0.01). Plasma phylloquinone and adjusted ucOC were inversely related in postmenopausal British women (R2=32.4%; P=0.0008). ApoE4 frequency was Gambian 32.6%, British 13.8% and Chinese 6%. A lower adjusted ucOC was associated with apoE2 genotype in British and Chinese women. Ethnic differences in adjusted ucOC persisted after adjustment for phylloquinone and apoE genotype. CONCLUSION: These preliminary data indicate suboptimal vitamin K status in postmenopausal British compared to Chinese and Gambian women. Ethnic differences in apoE genotype may also influence osteocalcin gamma-carboxylation status. The study highlights the need for larger epidemiological investigations of ethnic differences in vitamin K status and the possible implications to bone health.
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Antifibrinolíticos/sangre , Apolipoproteínas E/genética , Osteocalcina/metabolismo , Osteoporosis Posmenopáusica/etnología , Osteoporosis Posmenopáusica/epidemiología , Vitamina K 1/sangre , Adulto , Anciano , China/etnología , Estudios Transversales , Inglaterra/etnología , Femenino , Gambia/etnología , Genotipo , Humanos , Persona de Mediana Edad , Osteocalcina/sangre , Osteoporosis Posmenopáusica/metabolismo , Posmenopausia/etnología , Posmenopausia/metabolismo , Premenopausia/etnología , Premenopausia/metabolismo , Factores de Riesgo , Vitamina K 1/administración & dosificaciónRESUMEN
The concentrations of CF(3)-containing compounds in archived air samples collected at Cape Meares, Oregon, from 1978 to 1997, at Point Barrow, Alaska, from 1995 to 1998, and at Palmer Station, Antarctica, from 1991 to 1997, were determined by high resolution gas chromatography and high resolution mass spectrometry. The CF(3)-containing compounds measured by this method and discussed here are: the perfluorinated compound, C(3)F(8) (FC 218); four perhalogenated compounds, CF(3)Cl (CFC 13), CF(3)CF(2)Cl (CFC 115), CF(3)CFCl(2) (CFC 114a), and CF(3)Br (Halon 1301); and three hydrofluorocompounds, CF(3)H (HFC 23), CF(3)CH(3) (HFC 143a), and CF(3)CH(2)F (HFC 134a). For four of these compounds, very few measurements have been previously reported. The atmospheric concentrations of all of the CF(3)-containing compounds continuously increased in time over the sample collection periods. From these data, the annual rates of emission into the atmosphere have been estimated. The emission rates fall into one of three distinct categories. The annual emission rates of C(3)F(8), CF(3)H, CF(3)CH(3), and CF(3)CH(2)F have continuously increased over the last two decades. That of CF(3)CFCl(2) has decreased continuously. Emission rates for CF(3)Cl, CF(3)CF(2)Cl, and CF(3)Br reached maximum levels in the late 1980s, and have been decreasing in the 1990s. The emission rates of C(3)F(8), CF(3)CH(3) and CF(3)CH(2)F were nearly zero 20 years ago but have increased rapidly during the last decade.
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Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Hidrocarburos Halogenados/análisis , Modelos Químicos , Alaska , Regiones Antárticas , Cromatografía de Gases y Espectrometría de Masas , OregonRESUMEN
OBJECTIVE: To compare the pharmacokinetics and efficacy of oral versus intravenous mixed micellar vitamin K prophylaxis in infants with cholestatic liver disease, a known risk factor for vitamin K deficiency bleeding. DESIGN: Prospective randomised controlled study. SETTING: Paediatric Liver Unit. PATIENTS: Forty four infants less than 6 months of age with conjugated hyperbilirubinaemia. MAIN OUTCOME MEASURES: Serum concentrations of vitamin K(1) and undercarboxylated prothrombin (PIVKA-II; a sensitive functional indicator of vitamin K status) before and for up to four days after a single dose of mixed micellar K(1) 1 mg intravenously or 2 mg orally. Comparison of K(1) levels 24 hours after oral K(1) with those from 14 healthy newborns given the same dose. RESULTS: At admission, 18 infants (41%) had elevated levels of serum PIVKA-II and eight (18%) had low K(1) concentrations, indicative of subclinical vitamin K deficiency. Median serum K(1) concentrations were similar in the oral and intravenous groups at baseline (0.92 v 1.15 ng/ml), rising to 139 ng/ml six hours after intravenous K(1) but to only 1.4 ng/ml after oral administration. In the latter group, the low median value (0.95 ng/ml) and wide range (< 0.15-111 ng/ml) of serum K(1) compared unfavourably with the much higher levels (median 77, range 11-263 ng/ml) observed in healthy infants given the same oral dose, and suggested impaired and erratic intestinal absorption in cholestatic infants. The severity of malabsorption was such that only 4/24 (17%) achieved an incremental rise in serum K(1) > 10 ng/ml. CONCLUSIONS: The intestinal absorption of mixed micellar K(1) is unreliable in infants with conjugated hyperbilirubinaemia. Given the strong association between cholestasis and late vitamin K deficiency bleeding, these data provide an explanation for the failure of some oral vitamin K(1) prophylaxis regimens in infants with latent cholestasis.
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Antifibrinolíticos/farmacocinética , Hiperbilirrubinemia/metabolismo , Absorción Intestinal , Vitamina K 1/farmacocinética , Sangrado por Deficiencia de Vitamina K/prevención & control , Administración Oral , Antifibrinolíticos/administración & dosificación , Femenino , Humanos , Lactante , Recién Nacido , Inyecciones Intravenosas , Masculino , Micelas , Estudios Prospectivos , Vitamina K 1/administración & dosificación , Deficiencia de Vitamina K/complicaciones , Deficiencia de Vitamina K/tratamiento farmacológico , Sangrado por Deficiencia de Vitamina K/etiologíaRESUMEN
Data from weekly global measurements of nitrous oxide from 1981 to the end of 1996 are presented. The results show that there is more N2O in the northern hemisphere by about 0.7 +/- 0.04 ppbv, and the Arctic to Antarctic difference is about 1.2 +/- 0.1 ppbv. Concentrations at locations influenced by continental air are higher than at marine sites, showing the existence of large land-based emissions. For the period studied, N2O increased at an average rate of about 0.6 ppbv/year (approximately 0.2%/year) although there were periods when the rates were substantially different. Using ice core data, a record of N2O can be put together that goes back about 1000 years. It shows pre-industrial levels of about 287 +/- 1 ppbv and that concentrations have now risen by about 27 ppbv or 9.4% over the last century. The ice core data show that N2O started increasing only during the 20th century. The data presented here represent a comprehensive view of the present global distribution of N20 and its historical and recent trends.
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Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/historia , Óxido Nitroso/análisis , Óxido Nitroso/historia , Regiones Antárticas , Regiones Árticas , Monitoreo del Ambiente , Historia del Siglo XV , Historia del Siglo XVI , Historia del Siglo XVII , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia Medieval , Hielo , Estudios RetrospectivosRESUMEN
Intake and sources of phylloquinone (vitamin K1) were examined according to socio-demographic and lifestyle factors in free-living British people aged 65 years and over, from the 1994-5 National Diet and Nutrition Survey. Complete 4-d weighed dietary records were obtained from 1152 participants living in private households. Using newly-available, mainly UK-specific food content data, the weighted geometric mean intake of phylloquinone was estimated at 65 (95 % CI 62, 67) microg/d for all participants, with higher intakes in men than in women (70 v. 61 microg/d respectively, P<0.01). The mean nutrient densities of phylloquinone intake were 9.3 and 10.5 microg/MJ for men and women respectively (P<0.01), after adjusting for age group, region and smoking status. Of all the participants, 59 % had phylloquinone intakes below the current guideline for adequacy of 1 microg/kg body weight per d. Participants aged 85 years and over, formerly in manual occupations, or living in Scotland or in northern England reported lower phylloquinone intakes than their comparative groups. Overall, vegetables contributed 60 % of total phylloquinone intake, with cooked green vegetables providing around 28 % of the total. Dietary supplements contributed less than 0.5 % of phylloquinone intake. Participants living in northern England or in Scotland, in particular, derived less phylloquinone from vegetables than those living in southern England.
Asunto(s)
Antifibrinolíticos/administración & dosificación , Estilo de Vida , Vitamina K 1/administración & dosificación , Anciano , Anciano de 80 o más Años , Encuestas sobre Dietas , Femenino , Humanos , Masculino , Encuestas Nutricionales , Estaciones del Año , Clase Social , Reino Unido , Verduras/químicaRESUMEN
Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994-5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0.36 (inner 95% range [corrected] 0.06, 2.01) and 0.24 (inner 94% range [corrected] 0.06, 0.96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r 0.18 and 0.30 respectively, both P<0.001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, alpha- and gamma-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.
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Antifibrinolíticos/sangre , Vitamina K 1/sangre , Anciano , Anciano de 80 o más Años , Antifibrinolíticos/administración & dosificación , Encuestas sobre Dietas , Femenino , Humanos , Estilo de Vida , Masculino , Encuestas Nutricionales , Valores de Referencia , Estaciones del Año , Factores Sexuales , Clase Social , Reino Unido , Vitamina K 1/administración & dosificaciónRESUMEN
Among the proteins known or suspected to be involved in bone and vascular biology are several members of the vitamin K-dependent or Gla protein family. This review focuses on the role of two of these: osteocalcin and matrix Gla protein. Osteocalcin metabolism has been implicated in the pathogenesis of osteoporosis through an unknown mechanism that may be linked to suboptimal vitamin K status resulting in its undercarboxylation and presumed dysfunction. Recent studies that have investigated this hypothesis are discussed, as are recent promising clinical studies of vitamin K supplementation in osteoporosis. A recently delineated function of matrix Gla protein is as a powerful inhibitor of calcification of arteries and cartilage. In the period covered by this review there have been several landmark studies using cell systems, whole animals and genetic techniques that have consolidated and extended our knowledge of the role of matrix Gla protein in the prevention of ectopic calcification.
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Huesos/fisiología , Calcinosis , Osteocalcina/metabolismo , Osteoporosis/fisiopatología , Enfermedades Vasculares/fisiopatología , Vitamina K/fisiología , Humanos , Osteocalcina/antagonistas & inhibidores , Osteoporosis/prevención & control , Enfermedades Vasculares/prevención & control , Vitamina K/farmacologíaRESUMEN
This paper reports the compilation of a food composition database for phylloquinone (vitamin K1) derived from the direct analysis of foods, recipe calculation and the assignment of values based on food similarities. All the basic and other food items used in these calculations had been analysed by HPLC and about 170 of the items had been obtained and assayed in the UK. Recipe calculations took account of the cooking method and changes in water and fat content. Currently, approximately 1501 food items with Royal Society of Chemistry/Ministry of Agriculture, Fisheries and Food food codes have been allocated a vitamin K1 value, and a further 282 new recipe codes are included in the database. Representative values from each food group are reported together with an indication of the potential variation. Detailed examples of some recipe calculations are included, and also the impact of changing the type of fat in recipes. Vitamin K1 is associated with, and most abundant in, photosynthetic tissues of plants. Accordingly, the highest concentrations (3000-6000 micrograms/kg) are found in dark-green leafy vegetables and herbs, such as kale, parsley, spinach and green cabbage. Intermediate concentrations (1000-2000 micrograms/kg) are found in plants with paler leaves such as white cabbage and lettuce or in green, non-leafy vegetables such as broccoli and brussel sprouts. Fats and oils contain variable amounts of vitamin K1 with the highest concentrations (300-1300 micrograms/kg) in soyabean, rapeseed and olive oils and the margarines based on them. Other foods such as dairy products, meat dishes and cereal-based foods (bread, biscuits, cakes, desserts etc.), although not in themselves particularly rich in vitamin K1 (< 200 micrograms/kg), may contribute significantly to intakes when consumption of green vegetables is poor. Within the scope of this present study, it has not been possible to address issues such as inter-sample variability, losses during storage or the bioavailability from different foods and further work on these aspects is needed.
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Bases de Datos Factuales , Análisis de los Alimentos , Vitamina K 1/análisis , Apiaceae/química , Brassica/química , Cromatografía Líquida de Alta Presión , Culinaria , Productos Lácteos/análisis , Grano Comestible/química , Frutas/química , Humanos , Lactuca/química , Carne/análisis , Aceites de Plantas/análisis , Valores de ReferenciaAsunto(s)
Conductos Biliares Intrahepáticos/anomalías , Hemorragia Cerebral/etiología , Deficiencia de Vitamina K/complicaciones , Deficiencia de Vitamina K/tratamiento farmacológico , Vitamina K/uso terapéutico , Adulto , Conductos Biliares Intrahepáticos/patología , Resultado Fatal , Femenino , Humanos , Lactante , MasculinoRESUMEN
OBJECTIVE: To compare a new oral preparation of vitamin K1 (Konakion MM) containing lecithin and glycocholic acid with a standard intramuscular (IM) preparation during the first 8 weeks of life in exclusively breast fed infants. METHODS: Infants were randomised at birth to the IM group (1 mg vitamin K) or the oral group (2 mg given at birth and repeated at 7 and 30 days of life). Prothrombin time (INR), plasma vitamin K1, and PIVKA II (undercarboxylated prothrombin) were monitored at 14, 30, and 56 days of age. RESULTS: Seventy nine infants were randomised to the oral group and 77 to the IM group. Sixty seven infants in each group completed eight weeks of the study. Prothrombin times did not differ between the two groups. Mean (SD) plasma vitamin K1 values (in ng/ml) decreased in both groups over time, but were higher in the oral group at 14 and 56 days: 2.0 (1.6) v 1.3 (1.1) at 14 days; 0.5 (0.3) v 0.5 (0.7) at 30 days; and 0.5 (0.8) v 0.2 (0.2) at 56 days of life. PIVKA II was raised (> or = 0.1 AU/ml) in cord blood in 47% of the infants. By 14 days, only one infant in each group had a raised PIVKA II value and both of these initially had high concentrations of PIVKA II in cord blood. At 30 days, there were no raised PIVKA II values. At 56 days, there were no raised PIVKA II values in the oral group, although three infants in the IM group had raised values. CONCLUSIONS: Plasma vitamin K concentrations were at least equal or significantly higher in babies given oral vitamin K supplements compared with IM treated babies at the time points measured. Through the first 8 weeks of life, multiple doses of the new oral preparation maintain haemostasis and vitamin K status in breast fed infants at least equal to that of the intramuscular preparation.
Asunto(s)
Biomarcadores , Lactancia Materna , Deficiencia de Vitamina K/prevención & control , Vitamina K/administración & dosificación , Administración Oral , Femenino , Sangre Fetal/química , Humanos , Recién Nacido , Inyecciones Intramusculares , Masculino , Precursores de Proteínas/análisis , Protrombina/análisis , Tiempo de Protrombina , Vitamina K/sangre , Vitamina K/uso terapéutico , Deficiencia de Vitamina K/sangreAsunto(s)
Vitamina K/metabolismo , Animales , Transporte Biológico Activo , Proteínas Sanguíneas/metabolismo , Ligasas de Carbono-Carbono/metabolismo , Dieta , Proteínas de la Matriz Extracelular/metabolismo , Hemostasis , Historia del Siglo XX , Humanos , Absorción Intestinal , NAD(P)H Deshidrogenasa (Quinona)/antagonistas & inhibidores , Necesidades Nutricionales , Procesamiento Proteico-Postraduccional , Vitamina K/química , Vitamina K/historiaRESUMEN
This investigation of 68 hemodialysis patients (ages 33 to 91) analyzed the association of biochemical indicators of vitamin K nutriture and bone metabolism, and related both to past bone fracture history and prospective bone fracture risk. Phylloquinone concentrations were significantly lower in the 23 patients with previous fractures compared to those without (0.93 vs. 1.50 nmol/liter, P < 0.003) and a smaller percentage of their serum osteocalcin was carboxylated (48.8 vs. 53.6%, P < 0.03). The 41 patients who never had fractures had nearly three times higher phylloquinone concentrations than the nine patients with fractures during a four-year follow-up period (1.59 vs. 0.55 nmol/liter, P < 0.002) and more carboxylated serum osteocalcin (55.2 vs. 42.0%, P < 0.01). None of the patients with phylloquinone concentrations over 2.2 nmol/liter had elevated intact parathyroid hormone (iPTH) concentrations, and only patients with less than 1 nmol/liter phylloquinone had severe hyperparathyroidism (iPTH > 300 ng/liter). Our data thus indicate that suboptimal vitamin K nutriture in hemodialysis patients is associated both with increased bone fracture risk and with a high prevalence of hyperparathyroidism.