Concentrations of Circulating Phylloquinone, but Not Cerebral Menaquinone-4, Are Positively Correlated with a Wide Range of Cognitive Measures: Exploratory Findings in Centenarians.

BACKGROUND: Vitamin K (VK) exists in the form of phylloquinone (PK) and menaquinones (MKs). Roles of VK on cognitive health in the elderly are emerging, but there is limited evidence on VK uptake and metabolism in human brain. OBJECTIVES: The primary objective of this study was to characterize VK distribution in brains of an elderly population with varied cognitive function. In addition, associations among circulating (a biomarker of VK intake) and cerebral VK concentrations and cognition were investigated. METHODS: Serum or plasma (n = 27) and brain samples from the frontal cortex (FC; n = 46) and the temporal cortex (TC; n = 33) were acquired from 48 decedents (aged 98-107 y; 25 demented and 23 nondemented) enrolled in the Georgia Centenarian Study. Both circulating and brain VK concentrations were measured using HPLC with fluorescence detection. Cognitive assessment was performed within 1 y prior to mortality. Partial correlations between serum/plasma or cerebral VK concentrations and cognitive function were performed, adjusting for covariates and separating by dementia and antithrombotic use. RESULTS: MK-4 was the predominant vitamer in both FC (mean ± SD = 4.92 ± 2.31 pmol/g, ≥89.15% ± 5.09% of total VK) and TC (4.60 ± 2.11 pmol/g, ≥89.71% ± 4.43% of total VK) regardless of cognitive status. Antithrombotic users had 34.0% and 53.9% lower MK-4 concentrations in FC (P < 0.05) and TC (P < 0.001), respectively. Circulating PK was not correlated with cerebral MK-4 or total VK concentrations. Circulating PK concentrations were significantly associated with a wide range of cognitive measures in nondemented centenarians (P < 0.05). In contrast, cerebral MK-4 concentrations were not associated with cognitive performance, either before or after exclusion of antithrombotic users. CONCLUSIONS: Circulating VK concentrations are not related to cerebral MK-4 concentrations in centenarians. Cerebral MK-4 concentrations are tightly regulated over a range of VK intakes and cognitive function. Circulating PK may reflect intake of VK-rich foods containing other dietary components beneficial to cognitive health. Further investigation of VK uptake and metabolism in the brain is warranted.

Vitamin K status and inflammation are associated with cognition in older Irish adults.

Studies have shown associations between reduced vitamin K status and poor cognitive function. However, despite this apparent link, direct studies measuring cognitive function, vitamin K status and inflammation are lacking. In the current study, The ELDERMET cohort was investigated to identify associations between cognition, vitamin K status and inflammation. The primary aim of the ELDERMET study was to investigate the relationship between gut bacteria, diet, lifestyle and health in 500 older Irish adults. Significant differences in serum phylloquinone, dietary phylloquinone and inflammatory markers were found across varying levels of cognitive function, after controlling for sex, age, body mass index (BMI), triglycerides and blood pressure. In addition, significantly higher levels of dietary phylloquinone were found in those with better cognition compared to those with the poorest function. Higher levels of inflammatory were also associated with poor cognition. Furthermore, both dietary and serum phylloquinone were significant independent predictors of good cognitive function, after controlling for confounders. This study highlights the importance of dietary vitamin K as a potentially protective cognitive factor; it also provides evidence for the correlation between cognition and inflammation. Strategies should be devised by which elderly populations can access rich dietary sources of phylloquinone to maintain cognition.

Plasma Response to Deuterium-Labeled Vitamin K Intake Varies by TG Response, but Not Age or Vitamin K Status, in Older and Younger Adults.

Background: Phylloquinone is the primary form of vitamin K in the diet and circulation. Large intra- and interindividual variances in circulating phylloquinone have been partially attributed to age. However, little is known about the nondietary factors that influence phylloquinone absorption and metabolism. Similarly, it is not known if phylloquinone absorption is altered by the individual's existing vitamin K status. Objective: The purpose of this secondary substudy was to compare plasma response with deuterium-labeled phylloquinone intake in older and younger adults after dietary phylloquinone depletion and repletion. Methods: Forty-two older [mean ± SD age: 67.2 ± 8.0 y; body mass index (BMI; in kg/m2): 25.4 ± 4.6; n = 12 men, 9 women] and younger (mean ± SEM age: 31.8 ± 6.6 y; BMI: 25.5 ± 3.3; n = 9 men, 12 women) adults were maintained on sequential 28-d phylloquinone depletion (∼10 µg phylloquinone/d) and 28-d phylloquinone repletion (∼500 µg phylloquinone/d) diets. On the 23rd d of each diet phase, participants consumed deuterated phylloquinone-rich collard greens (2H-phylloquinone). Plasma and urinary outcome measures over 72 h were compared by age group, sex, and dietary phase via 2-factor repeated-measures ANOVA. Results: The plasma 2H-phylloquinone area under the curve (AUC) did not differ in response to phylloquinone depletion or repletion, but was 34% higher in older than in younger adults (P = 0.02). However, plasma 2H-phylloquinone AUC was highly correlated with the serum triglyceride (TG) AUC (r2 = 0.45). After adjustment for serum TG response, the age effect on the plasma 2H-phylloquinone AUC was no longer significant. Conclusions: Plasma 2H-phylloquinone response did not differ between phylloquinone depletion and repletion in older and younger adults. The age effect observed was explained by the serum TG response and was completely attenuated after adjustment. Plasma response to phylloquinone intake, therefore, seems to be a predominantly lipid-driven effect and not dependent on existing vitamin K status. More research is required to differentiate the effect of endogenous compared with exogenous lipids on phylloquinone absorption. This trial was registered at clinicaltrials.gov as NCT00336232.

Assessment of antioxidant enzymes, total sialic acid, lipid bound sialic acid, vitamins and selected amino acids in children with phenylketonuria.

BACKGROUND: In this study, children with phenylketonuria and healthy control subjects were assessed for glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) activity, malondialdehyde (MDA), glutathione (GSH), retinol, cholecalciferol, α-tocopherol, phylloquinone, total sialic acid (TSA), lipid bound sialic acid (LSA), total antioxidant (TAS), total oxidation (TOS), and amino acid levels, and the relationships of these variables with phenylketonuria were evaluated. METHODS: The study included 60 children with phenylketonuria and 30 control subjects. Children with phenylketonuria were divided into hyperphenylalaninemia (HPA) and amino acid mixture (AAM) groups. RESULTS: The HPA group had significantly lower levels of GSH-Px, CAT, GSH, TAS, α-aminobutyric acid, and taurine levels (p < 0.01, p < 0.05, p < 0.05, p < 0.001, p < 0.01, p < 0.05, respectively) than the control group. Additionally, the AAM group had significantly lower levels of CAT, TAS, and phylloquinones (p < 0.05, p < 0.05, p < 0.05, respectively) than the control group. It was observed in our study that in the HPA group, a significantly strong positive linear correlation was observed between phenylalanine and α-aminoadipic acid (r = 0.777; p = 0.002). CONCLUSIONS: It was concluded that the levels of α-aminoadipic acid and phylloquinone might be an appropriate choice for the determination of phenylketonuria in parallel with the levels of phenylalanine. α-aminobutyric acid and phylloquinone as a supplement can decrease HPA damage.

Prophylactic vitamin K for the prevention of vitamin K deficiency bleeding in preterm neonates.

BACKGROUND: Vitamin K is necessary for the synthesis of coagulation factors. Term infants, especially those who are exclusively breast fed, are deficient in vitamin K and consequently may have vitamin K deficiency bleeding (VKDB). Preterm infants are potentially at greater risk for VKDB because of delayed feeding and subsequent delay in the colonization of their gastrointestinal system with vitamin K producing microflora, as well as immature hepatic and hemostatic function.  OBJECTIVES: To determine the effect of vitamin K prophylaxis in the prevention of vitamin K deficiency bleeding (VKDB) in preterm infants. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 11), MEDLINE via PubMed (1966 to 5 December 2016), Embase (1980 to 5 December 2016), and CINAHL (1982 to 5 December 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles. SELECTION CRITERIA: Randomized controlled trials (RCTs) or quasi-RCTs of any preparation of vitamin K given to preterm infants. DATA COLLECTION AND ANALYSIS: We evaluated potential studies and extracted data in accordance with the recommendations of Cochrane Neonatal. MAIN RESULTS: We did not identify any eligible studies that compared vitamin K to no treatment.One study compared intravenous (IV) to intramuscular (IM) administration of vitamin K and compared various dosages of vitamin K. Three different prophylactic regimes of vitamin K (0.5 mg IM, 0.2 mg vitamin K1, or 0.2 mg IV) were given to infants less than 32 weeks' gestation. Given that only one small study met the inclusion criteria, we assessed the quality of the evidence for the outcomes evaluated as low.Intramuscular versus intravenousThere was no statistically significant difference in vitamin K levels in the 0.2 mg IV group when compared to the infants that received either 0.2 or 0.5 mg vitamin K IM (control) on day 5. By day 25, vitamin K1 levels had declined in all of the groups, but infants who received 0.5 mg vitamin K IM had higher levels of vitamin K1 than either the 0.2 mg IV group or the 0.2 mg IM group.Vitamin K1 2,3-epoxide (vitamin K1O) levels in the infants that received 0.2 mg IV were not statistically different from those in the control group on day 5 or 25 of the study. All of the infants had normal or supraphysiologic levels of vitamin K1 concentrations and either no detectable or insignificant amounts of prothrombin induced by vitamin K absence-II (PIVKA II).Dosage comparisonsDay 5 vitamin K1 levels and vitamin K1O levels were significantly lower in the 0.2 mg IM group when compared to the 0.5 mg IM group. On day 25, vitamin K1O levels and vitamin K1 levels in the 0.2 mg IM group and the 0.5 mg IM group were not significantly different. Presence of PIVKA II proteins in the 0.2 mg IM group versus the 0.5 mg IM group was not significantly different at day 5 or 25 of the study. AUTHORS' CONCLUSIONS: Preterm infants have low levels of vitamin K and develop detectable PIVKA proteins during the first week of life. Despite being at risk for VKDB, there are no studies comparing vitamin K versus non-treatment and few studies that address potential dosing strategies for effective treatment. Dosage studies suggest that we are currently giving doses of vitamin K to preterm infants that lead to supraphysiologic levels. Because of current uncertainty, clinicians will have to extrapolate data from term infants to preterm infants. Since there is no available evidence that vitamin K is harmful or ineffective and since vitamin K is an inexpensive drug, it seems prudent to follow the recommendations of expert bodies and give vitamin K to preterm infants. However, further research on appropriate dose and route of administration is warranted.

Fat soluble vitamin levels in children with newly diagnosed celiac disease, a case control study.

BACKGROUND: In children diagnosed with celiac disease, fat soluble vitamin levels were aimed to be evaluated and it was intended to determine whether fat soluble vitamin levels were needed to be assessed routinely in these patients during diagnosis. METHODS: Between May 2015-May 2016, diagnosis symptoms of celiac patients (CD) in newly diagnosed pediatric group were questioned, fat soluble vitamin levels simultaneous with intestinal biopsies were evaluated. Vitamin levels were compared with those of healthy control group. RESULTS: A total of 52 patients involving 27 female (51.9%), 25 male (48.1%); and a total of 50 healthy control group including 25 female (50%), 25 male (50%) were evaluated. The average age of patients was 9 ± 4.3 years, and their average weight was determined as 16.2 ± 6.3 kg. Growth retardation was the most frequent symptom in our patients (61.5%). Abdominal pain (51.9%) and diarrhea (11.5%) are among the other most commonly seen symptoms. In the histological examination of patients, Marsh 3B n = 23 (45.1%) was mostly established. Vitamin A and vitamin D levels of patients were determined significantly lower compared to those of control group. Vitamin A and vitamin D deficiencies were identified significantly higher compared to those of healthy control group. Vitamin D insufficiency was observed in 48 patients (92.3%) and vitamin D deficiency was determined in 32 (61.5%) out of 48. Vitamin A deficiency was established in 17 (32.7%) patients. Vitamin E and vitamin K1 deficiency were determined in no patients. In the healthy control group, vitamin D deficiency was seen in 2 (4%) patients, vitamin D insufficiency was determined in 9 (18%) patients. Other vitamin levels were identified at normal levels in the healthy group. CONCLUSIONS: In newly diagnosed children with CD, a significant lowness was established in vitamin D and A. The evaluation of vitamin A and D levels will be helpful in the course of diagnosis in these patients.

Determination of vitamins K1 , MK-4, and MK-7 in human serum of postmenopausal women by HPLC with fluorescence detection.

BACKGROUND: New high-performance liquid chromatography (HPLC) method was developed for the determination of vitamin K1 and two forms of vitamin K2 (MK-4 and MK-7) in human serum, and the levels of vitamin K were determined in 350 samples of postmenopausal women. METHODS: Vitamin K was determined by HPLC with fluorescence detection after postcolumn zinc reduction. The detection was performed at 246 nm (excitation) and 430 nm (emission). The internal standard and 2 mL of ethanol were added to 500 µL of serum. The mixture was extracted with 4 mL of hexane, and solid phase extraction was then used. RESULTS: The HLPC method was fully validated. The intra- and interday accuracy and precision were evaluated on two QC samples by multiple analysis, and CV were less than 10%. The limit of quantification for MK-4 was found at 0.04 ng/mL, for K1 0.03 ng/mL, and for MK-7 0.03 ng/mL. The mean recoveries of the corresponding compounds were 98%-110%. Serum levels of MK-4, K1 , and MK-7 in postmenopausal women with osteoporosis were 0.890 ± 0.291 ng/mL, 0.433 ± 0.394 ng/mL, and 1.002 ± 1.020 ng/mL, respectively (mean ± SD). Serum levels of MK-4, K1 , and MK-7 in postmenopausal women without osteoporosis were 0.825 ± 0.266 ng/mL, 0.493 ± 0.399 ng/mL, and 1.186 ± 1.076 ng/mL, respectively (mean ± SD). CONCLUSION: New HPLC method for the determination of vitamins K1 , MK-4, and MK-7 in serum was evaluated and validated. This method is highly specific and sensitive with the low limit of quantification.

Circulating Vitamin K Is Inversely Associated with Incident Cardiovascular Disease Risk among Those Treated for Hypertension in the Health, Aging, and Body Composition Study (Health ABC).

Background: A role for vitamin K in coronary artery calcification (CAC), a subclinical manifestation of cardiovascular disease (CVD), has been proposed because vitamin K-dependent proteins, including the calcification inhibitor matrix Gla protein (MGP), are present in vascular tissue. Observational studies found that low circulating phylloquinone (vitamin K-1) was associated with increased CAC progression, especially in persons treated for hypertension. It is unknown whether hypertension treatment modifies this putative role of vitamin K in clinical CVD risk.Objective: We determined the association between vitamin K status and incident clinical CVD in older adults in the Health ABC (Health, Aging, and Body Composition Study) and whether the association differed by hypertension treatment status.Methods: Plasma phylloquinone was measured in 1061 participants free of CVD (70-79 y of age, 58% women, 39% black). Plasma uncarboxylated MGP [(dp)ucMGP] was measured in a subset of 635 participants. Multivariate Cox models estimated the HR for incident CVD over 12.1 follow-up years. Effect modification by hypertension was tested with the use of interaction terms.Results: Neither low plasma phylloquinone (<0.2 nmol/L) nor elevated (dp)ucMGP (≥574 pmol/L) was significantly associated with incident CVD [respective HRs (95% CIs): 1.27 (0.75, 2.13) and 1.02 (0.72, 1.45)]. In participants treated for hypertension (n = 489; 135 events), low plasma phylloquinone was associated with higher CVD risk overall (HR: 2.94; 95% CI: 1.41, 6.13). In those with untreated hypertension (n = 153; 48 events) and without hypertension (n = 418; 92 events), low plasma phylloquinone was not associated with incident CVD. The association between high (dp)ucMGP did not differ by hypertension treatment status (P-interaction = 0.72).Conclusions: Vitamin K status was not significantly associated with CVD risk overall, but low plasma phylloquinone was associated with a higher CVD risk in older adults treated for hypertension. Additional evidence from larger clinical studies is needed to clarify the importance of vitamin K to CVD in persons treated for hypertension, a segment of the population at high risk of clinical CVD events.

Vitamin D Status and Bone Mineral Density is Influenced by Vitamin D Supplementation and Vitamin K1 Intake in Adults with Diabetes and Chronic Kidney Disease.

PURPOSE: Patients with diabetes (DM) and chronic kidney disease (CKD) are at increased risk for suboptimal bone health. The study objective was to investigate the relationships between vitamin D (vitD), vitamin K1 (vitK1), and calcium intake with bone mineral density (BMD) and vitamin D status in an ambulatory population with DM and CKD. METHODS: Adults (age 18-80 years; n = 62) with DM and CKD (stages 1-4) were recruited from the Northern Alberta Renal Program. Primary outcome variables included vitD, vitK1, and calcium intake; serum 25(OH)D, 1,25(OH)2D; and BMD as measured by dual X-ray absorptiometry. Statistical significance was determined at P < 0.05. RESULTS: Participants met the estimated average requirement or adequate intake for vitD, vitK1, and calcium intake in 73% (n = 45), 66% (n = 39), and 52% (n = 31), respectively, with a combined intake of micronutrient supplementation and diet. Participants had serum 25(OH)D concentrations ≥75 nmol/L (n = 41), normal BMDs (n = 48), and 66% (n = 41/62) were taking vitD supplements (>1000 IU/D). BMD was positively influenced by serum 25(OH)D. However, serum 25(OH) ≥100 nmol/L was associated with lower BMD (absolute and T-scores) for whole-body and spine (P ≤ 0.05). VitK1 intake (≥200 µg/day) was associated with higher whole-body and femoral-neck BMDs (absoluteand T-scores; P ≤ 0.05). CONCLUSION: VitD status and BMD in adults with DM and CKD was influenced by vitD supplementation and vitK1 intake.

A combination of low serum concentrations of vitamins K1 and D is associated with increased risk of hip fractures in elderly Norwegians: a NOREPOS study.

UNLABELLED: The present study investigated the risk of incident hip fractures according to serum concentrations of vitamin K1 and 25-hydroxyvitamin D in elderly Norwegians during long-term follow-up. The results showed that the combination of low concentrations of both vitamin D and K1 provides a significant risk factor for hip fractures. INTRODUCTION: This case-cohort study aims to investigate the associations between serum vitamin K1 and hip fracture and the possible effect of 25-hydroxyvitamin D (25(OH)D) on this association. METHODS: The source cohort was 21,774 men and women aged 65 to 79 years who attended Norwegian community-based health studies during 1994-2001. Hip fractures were identified through hospital registers during median follow-up of 8.2 years. Vitamins were determined in serum obtained at baseline in all hip fracture cases (n = 1090) and in a randomly selected subcohort (n = 1318). Cox proportional hazards regression with quartiles of serum vitamin K1 as explanatory variable was performed. Analyses were further performed with the following four groups as explanatory variable: I: vitamin K1 ≥ 0.76 and 25(OH)D ≥ 50 nmol/l, II: vitamin K1 ≥ 0.76 and 25(OH)D < 50 nmol/l, III: vitamin K1 < 0.76 and 25(OH)D ≥ 50 nmol/l, and IV: vitamin K1 < 0.76 and 25(OH)D < 50 nmol/l. RESULTS: Age- and sex-adjusted analyses revealed an inverse association between quartiles of vitamin K1 and the risk of hip fracture. Further, a 50 % higher risk of hip fracture was observed in subjects with both low vitamin K1 and 25(OH)D compared with subjects with high vitamin K1 and 25(OH)D (HR 1.50, 95 % CI 1.18-1.90). The association remained statistically significant after adjusting for body mass index, smoking, triglycerides, and serum α-tocopherol. No increased risk was observed in the groups low in one vitamin only. CONCLUSION: Combination of low concentrations of vitamin K1 and 25(OH)D is associated with increased risk of hip fractures.

Phylloquinone Intakes and Food Sources and Vitamin K Status in a Nationally Representative Sample of Irish Adults.

BACKGROUND: Data from a nationally representative sample of 18- to 64-y-old Irish adults conducted in 1999 highlighted low phylloquinone intakes. That survey, however, did not include older adults (aged ≥65 y), a subgroup that is potentially at higher risk of low phylloquinone intakes, or a biomarker of vitamin K status. OBJECTIVES: The objectives of this work were to measure the phylloquinone intake and its adequacy and the serum percentage of undercarboxylated osteocalcin (%ucOC), a vitamin K status biomarker, in a nationally representative sample of Irish adults aged 18-90 y, and to compare these newer data on dietary phylloquinone in adults aged 18-64 y with those from the previous survey. METHODS: Data and biobanked serum samples from the National Adult Nutrition Survey, a randomly selected sample of Irish adults aged 18-90 y (N = 1500), were accessed. Phylloquinone intakes were estimated from 4-d food diary data and were compared across age groups (18-35, 36-50, 51-64, and ≥65 y). Serum %ucOC was assessed by immunoassay (n = 692). RESULTS: The mean ± SD intake of phylloquinone from all sources was 85.2 ± 59.1 µg/d, 99% of which was derived from food. Phylloquinone intakes and serum %ucOC were significantly (P < 0.05) lower (14-25%) and higher (27-39%), respectively, in the 18- to 35-y age group than in the 36- to 50-y, 51- to 64-y, and ≥65-y age groups (no differences between these 3 groups; P > 0.2 in all cases). Mean phylloquinone intakes had increased (P < 0.01) modestly (6 µg/d) in 18-64-y-olds across a decade. Of the total study population, 55% had phylloquinone intakes below the United Kingdom recommended intake of 1 µg ⋅ kg body weight-1 ⋅ d-1 CONCLUSION: Our study shows that younger adults (aged 18-35 y) appear to be at higher risk of inadequate vitamin K intake and lower vitamin K status, the health implications of which are unclear and warrant further investigation.

Measurement of plasma vitamin K1 (phylloquinone) and K2 (menaquinones-4 and -7) using HPLC-tandem mass spectrometry.

BACKGROUND: Given the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin K1 (phylloquinone [PK]) and K2 (menaquinones [MK]-4 and -7). Furthermore, we investigated the association of fasting plasma vitamin K with functional vitamin K insufficiency in renal transplant recipients (RTR). METHODS: We used HPLC-tandem mass spectrometry with atmospheric pressure chemical ionization for measurement of plasma PK, MK-4, and MK-7. Solid-phase extraction was used for sample clean-up. Mass spectrometric detection was performed in multiple reaction monitoring mode. Functional vitamin K insufficiency was defined as plasma desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) >500 pmol/L. RESULTS: Lower limits of quantitation were 0.14 nmol/L for PK and MK-4 and 4.40 nmol/L for MK-7. Linearity up to 15 nmol/L was excellent. Mean recoveries were >92%. Fasting plasma PK concentration was associated with recent PK intake (ρ=0.41, p=0.002) and with plasma MK-4 (ρ=0.49, p<0.001). Plasma PK (ρ=0.38, p=0.003) and MK-4 (ρ=0.46, p<0.001) were strongly correlated with plasma triglyceride concentrations. Furthermore, we found that MK-4-triglyceride ratio, but not PK-triglyceride ratio, was significantly associated with functional vitamin K insufficiency (OR 0.22 [0.07-0.70], p=0.01) in RTR. CONCLUSIONS: The developed rapid and easy-to-use LC-MS/MS method for quantitative determination of PK, MK-4, and MK-7 in human plasma may be a good alternative for the labor-intensive and time-consuming LC-MS/MS methods and enables a higher sample throughput.

Impact of menaquinone-4 supplementation on coronary artery calcification and arterial stiffness: an open label single arm study.

BACKGROUND: Dietary intake of vitamin K has been reported to reduce coronary artery calcification (CAC) and cardiovascular events. However, it is unknown whether supplemental menaquinone (MK)-4 can reduce CAC or arterial stiffness. To study the effect of MK-4 supplementation on CAC and brachial ankle pulse wave velocity (baPWV). METHODS: This study is a single arm design to take 45 mg/day MK-4 daily as a therapeutic drug for 1 year. Primary endpoint was CAC score determined using 64-slice multislice CT (Siemens), and the secondary endpoint was baPWV measured before and 1 year after MK-4 therapy. RESULTS: A total of 26 patients were enrolled. The average age was 69 ± 8 years and 65 % were female. Plasma levels of phylloquinone (PK), MK-7, and MK4 were 1.94 ± 1.38 ng/ml, 14.2 ± 11.9 ng/ml and 0.4 ± 2.0 ng/ml, respectively, suggesting that MK-7 was the dominant vitamin K in the studied population. Baseline CAC and baPWV were 513 ± 773 and 1834 ± 289 cm/s, respectively. At 1 year following MK-4 supplementation, the values were 588 ± 872 (+14 %) and 1821 ± 378 cm/s (-0.7 %), respectively. In patients with high PIVKA-2, -18 % annual reduction of baPWV was observed. CONCLUSION: Despite high dose MK-4 supplementation, CAC increased +14 % annually, but baPWV did not change (-0.7 %). The benefits of MK-4 supplementation were only observed in patients with vitamin K insufficiencies correlated with high PIVKA-2 baseline levels, reducing baPWV but not CAC. TRIAL REGISTRATION: This study was registered as UMIN 000002760.

Phylloquinone concentrations and the risk of vascular calcification in healthy women.

OBJECTIVE: To investigate the association of plasma phylloquinone concentrations with coronary artery calcification (CAC) and vascular calcification. APPROACH AND RESULTS: In a prospective cohort of 508 postmenopausal women, plasma phylloquinone concentrations were measured by high-pressure liquid chromatography. Calcification was measured in the coronary arteries, aortic valve, mitral valve, and thoracic aorta by multidetector computed tomography. To combine these calcification scores, we dichotomized each of the 4 areas into present or absent. Because of the continuous measurement of CAC, we categorized this as calcification present if Agatston score was >0, and calcification score was calculated as the sum of the calcified areas. Multivariate-adjusted prevalence ratios and odds ratios were estimated using Poisson regression and multinomial logistic regression. After 8.5 years of follow-up, 22% of the women had no calcification, whereas 5% had calcification in all measured areas. Detectable phylloquinone concentrations were associated with increased CAC compared with nondetectable phylloquinone concentrations with a prevalence ratio of 1.34 (95% confidence interval, 1.01-1.77). When dividing women with detectable phylloquinone concentrations into low detectable (>0-0.70 nmol/L) and moderate to high detectable (>0.70 nmol/L) phylloquinone concentrations versus nondetectable phylloquinone concentrations, both were associated with increased CAC with a prevalence ratio of 1.32 (95% confidence interval, 0.99-1.76) and 1.36 (95% confidence interval, 1.02-1.81), respectively. Detectable phylloquinone concentrations were not associated with the number of calcified areas with an odds ratio(no versus ≥ 3 areas calcifications) of 1.60 (95% confidence interval, 0.65-3.99; P=0.31). CONCLUSIONS: Detectable phylloquinone concentrations are not associated with reduced vascular calcification but seemed to be associated with an increased prevalence of CAC.

Low-dose menaquinone-4 improves γ-carboxylation of osteocalcin in young males: a non-placebo-controlled dose-response study.

BACKGROUND: Menaquinone-4 is a type of vitamin K that has a physiological function in maintaining bone quality via γ-carboxylation of osteocalcin. However, little is known about the beneficial effect of intake of dosages below1500 µg/day. FINDINGS: Fifteen healthy males aged 25.0 years (median) participated in a non-placebo-controlled dose-examination study. They received menaquinone-4 daily for 5 weeks at 0, 300, 600, 900, and 1500 µg/day in weeks 1, 2, 3, 4, and 5, respectively. Compared with baseline, serum γ-carboxylated osteocalcin levels were significantly greater at an intake of 900 µg/day or more; serum undercarboxylated osteocalcin levels and the ratio of serum undercarboxylated osteocalcin to γ-carboxylated osteocalcin were significantly lower than baseline at doses of 600 µg/day or more. CONCLUSIONS: This preliminary graded-dose study suggested that menaquinone-4 supplementation at 600 µg/day or more is likely to be important in terms of vitamin K requirements for bone health.

Assessment of the effect of esterified propoxylated glycerol (EPG) on the status of fat-soluble vitamins and select water-soluble nutrients following dietary administration to humans for 8 weeks.

This double-blind, randomized, controlled study assessed the effect of esterified propoxylated glycerol (EPG) on fat-soluble vitamins and select nutrients in human subjects. For 8 weeks, 139 healthy volunteers consumed a core diet providing adequate caloric and nutrient intakes. The diet included items (spread, muffins, cookies, and biscuits) providing EPG (10, 25, and 40 g/day) vs. margarine alone (control). EPG did not significantly affect circulating retinol, α-tocopherol, or 25-OH D2, but circulating ß-carotene and phylloquinone were lower in the EPG groups, and PIVKA-II levels were higher; 25-OH D3 increased but to a lesser extent than the control. The effect might be related to EPG acting as a lipid "sink" during gastrointestinal transit. No effects were seen in secondary endpoint measures (physical exam, clinical pathology, serum folate, RBC folate, vitamin B12, zinc, iron, calcium, phosphorus, osteocalcin, RBP, intact PTH, PT, PTT, cholesterol, HDL-C, LDL-C, triglycerides). Gastrointestinal adverse events (gas with discharge; diarrhea; oily spotting; oily evacuation; oily stool; liquid stool; soft stool) were reported more frequently by subjects receiving 25 or 40 g/day of EPG. In general, the incidence and duration of these symptoms correlated directly with EPG dietary concentration. The results suggest 10 g/day of EPG was reasonably well tolerated.

A simple and sensitive method for determination of vitamins D3 and K1 in rat plasma: application for an in vivo pharmacokinetic study.

PURPOSE: To develop and to validate a simple but sensitive method for determination of vitamins D3 and K1 in rat plasma. METHODS: The sample treatment included protein precipitation by cold acetonitrile, evaporation, reconstitution with methanol and filtration. The chromatography conditions included Xterra RP18 3.5 µm 4.6 × 100 mm column at ambient temperature and mobile phase consisting of methanol/water (93/7, v/v) at 0.5 mL/min flow rate. Vitamin D3 and probucol were detected at 265 nm and vitamin K1 at 239 nm. Rats were administered intravenously by 0.1 mg/kg of vitamin D3 or K1 and the blood samples were withdrawn pre-administration and at pre-determined time points post-administration. The pharmacokinetic analysis was performed using a non-compartmental approach. RESULTS: The calibration curves in rat plasma were linear up to 5000 ng/mL for both vitamins. The limit of quantification (LOQ) was 20 ng/mL for vitamin D3 and 40 ng/mL for K1. Inter- and intra-day precision and accuracy were below 15%. The pharmacokinetic parameters of vitamin D3 following intravenous administration were: AUC0-∞ = 11323 ± 1081 h × ng/mL, Vd = 218 ± 80 mL/kg, CL = 8.9 ± 0.8 mL/h/kg, t1/2 = 16.8 ± 5 h; and of vitamin K1: AUC0-∞ = 2495 ± 297 h × ng/mL, Vd = 60 ±24 mL/kg, CL = 40.5 ± 5.1 mL/h/kg, t1/2 = 1.1 ±0.5 h. CONCLUSION: The developed HPLC-UV assay is a simple and sensitive method for the determination of vitamins D3 and K1 in rat plasma. A higher dose of vitamin K1 should be used in future studies for accurate estimation of pharmacokinetic parameters. The data show the suitability of the assay for pharmacokinetic studies in rats.

[Establishing reference ranges of serum vitamin K in healthy children].

Objective: To establish and validate reference intervals of serum vitamin K for healthy children in China. Methods: A cross-sectional study was conducted from January 2020 to May 2023, involving 807 healthy children aged 0 to 14 years, selected by stratified random sampling based on the population distribution of children in eastern, central, western, and northeastern China. Sample collection was carried out in 16 hospitals across 12 provinces, autonomous regions, and municipalities. Basic information of the children was collected using a standardized self-design questionnaire. Serum levels of vitamin K1 and vitamin K2 (menaquinone-4 (MK-4), menaquinone-7 (MK-7)) were measured using liquid chromatography-tandem mass spectrometry. The reference intervals was established by direct approach. The children were divided into different groups by age. Inter-group comparisons were conducted using the Kruskal-Wallis non-parametric test, and the reference intervals (P2.5-P97.5) were determined using non-parametric methods. Screening 40 healthy children for small sample validation based on age groups within the reference range(25 from eastern, 10 from central, and 5 from western regions). Results: The age of the 807 children was 5.00 (2.00, 9.81) years, and 495 (61.3%) were males and 312 (38.7%) females. Reference intervals were established for 795 children, of whom 303 children were aged 1 month to 3 years and 492 were aged 4 to 14 years. The reference intervals for serum vitamin K1 were 0.09-4.54 µg/L for children aged 1 month to 3 years, and 0.10-1.73 µg/L for 4-14 years. For MK-7, the intervals were 0.07-1.42 µg/L for 1 month to 3 years and 0.19-2.03 µg/L for 4-14 years. The reference intervals for MK-4 in children aged 1 month to 14 years were 0-0.42 µg/L. The measured values of serum vitamin K1, MK-4, and MK-7 in the validation samples did not exceed the reference limit in more than 2 samples. Conclusion: Reference intervals for vitamin K1, MK-4, and MK-7 in healthy children aged 1 month to 14 years have been established and validated, and can be used to assess vitamin K nutritional status in children.

Serum 25(OH)D and vitamin K1 levels in patients with severe motor and intellectual disability: A Japanese single-center experience.

PURPOSE: To investigate whether patients with severe motor and intellectual disability (SMID) have nutritional vitamin D and K insufficiencies and clarify the required vitamin supplementation. METHODS: This prospective observational study enrolled Japanese adults with SMID receiving institutionalized care who underwent blood sampling between February 2020 and February 2022 during annual medical checkups. Serum vitamin K1 and 25-hydroxy vitamin D (25(OH)D) levels were measured to determine their relationship with serum uncarboxylated osteocalcin (ucOC) levels. Vitamin D and K intake was compared among tube-fed and oral-intake patients with SMID and control participants using corresponding serum levels. RESULTS: The study included 124 patients with SMID (56 men and 68 women; mean age: 53.0 years) and 20 control participants. Serum 25(OH)D levels were significantly higher in the SMID group than in the control group and the oral intake SMID group than in the tube-fed SMID group. In the tube-fed SMID group, vitamin D intake was lower than the daily recommended intake and correlated with serum 25(OH)D levels. Daily vitamin K intake in the tube-fed group was lower than recommended but not correlated with serum vitamin K levels. Serum ucOC levels were significantly higher in the SMID group than in the control group. Tube feeding was significantly and positively correlated with serum 25(OH)D levels. Serum 25(OH)D levels were not correlated with serum vitamin K1 levels. CONCLUSIONS: The SMID group had higher ucOC levels than the control group, possibly owing to daily vitamin K and D deficiencies. Vitamin D supplementation is recommended to decrease ucOC levels.

Short-term treatment with cholestyramine increases long-acting anticoagulant rodenticide clearance from rabbits without affecting plasma vitamin K1 levels or blood coagulation.

Administration of high-dose vitamin K1 (VK1) overcomes coagulopathy and bleeding elicited by acute poisoning with long-acting anticoagulant rodenticides (LAARs). However, long-term (months) treatment is required due to long LAAR biological half-lives that may lead to poor compliance and recurrent coagulopathy. The half-lives of LAARs are extended by slow metabolism, and similar to warfarin, are thought to undergo enterohepatic recirculation. We now show that treatment with the bile acid sequestrant cholestyramine (CSA) administered concomitantly with VK1 decreases plasma LAAR levels and increases LAAR fecal excretion. Daily CSA treatment for 14 days did not reduce plasma VK1 levels, or increase prothrombin time. Collectively, these data show that CSA accelerates LAAR clearance from rabbits without adverse effects on VK1 anticoagulation, and could provide an additional therapeutic option for treatment of LAAR poisoning.