Biological Role of Vitamin K-With Particular Emphasis on Cardiovascular and Renal Aspects.

Vitamin K (VK) plays many important functions in the body. The most important of them include the contribution in calcium homeostasis and anticoagulation. Vascular calcification (VC) is one of the most important mechanisms of renal pathology. The most potent inhibitor of this process-matrix Gla protein (MGP) is VK-dependent. Chronic kidney disease (CKD) patients, both non-dialysed and hemodialysed, often have VK deficiency. Elevated uncarboxylated matrix Gla protein (ucMGP) levels indirectly reflected VK deficiency and are associated with a higher risk of cardiovascular events in these patients. It has been suggested that VK intake may reduce the VC and related cardiovascular risk. Vitamin K intake has been suggested to reduce VC and the associated cardiovascular risk. The role and possibility of VK supplementation as well as the impact of anticoagulation therapy on VK deficiency in CKD patients is discussed.

Fat-Soluble Vitamin Supplementation Using Liposomes, Cyclodextrins, or Medium-Chain Triglycerides in Cystic Fibrosis: A Randomized Controlled Trial.

Fat-soluble vitamin deficiency remains a challenge in cystic fibrosis (CF), chronic pancreatitis, and biliary atresia. Liposomes and cyclodextrins can enhance their bioavailability, thus this multi-center randomized placebo-controlled trial compared three-month supplementation of fat-soluble vitamins in the form of liposomes or cyclodextrins to medium-chain triglycerides (MCT) in pancreatic-insufficient CF patients. The daily doses were as follows: 2000 IU of retinyl palmitate, 4000 IU of vitamin D3, 200 IU of RRR-α-tocopherol, and 200 µg of vitamin K2 as menaquinone-7, with vitamin E given in soybean oil instead of liposomes. All participants received 4 mg of ß-carotene and 1.07 mg of vitamin K1 to ensure compliance with the guidelines. The primary outcome was the change from the baseline of all-trans-retinol and 25-hydroxyvitamin D3 concentrations and the percentage of undercarboxylated osteocalcin. Out of 75 randomized patients (n = 28 liposomes, n = 22 cyclodextrins, and n = 25 MCT), 67 completed the trial (89%; n = 26 liposomes, n = 18 cyclodextrins, and n = 23 MCT) and had a median age of 22 years (IQR 19-28), body mass index of 20.6 kg/m2 [18.4-22.0], and forced expiratory volume in 1 s of 65% (44-84%). The liposomal formulation of vitamin A was associated with the improved evolution of serum all-trans-retinol compared to the control (median +1.7 ng/mL (IQR -44.3-86.1) vs. -38.8 ng/mL (-71.2-6.8), p = 0.028). Cyclodextrins enhanced the bioavailability of vitamin D3 (+9.0 ng/mL (1.0-17.0) vs. +3.0 ng/mL (-4.0-7.0), p = 0.012) and vitamin E (+4.34 µg/mL (0.33-6.52) vs. -0.34 µg/mL (-1.71-2.15), p = 0.010). Liposomes may augment the bioavailability of vitamin A and cyclodextrins may strengthen the supplementation of vitamins D3 and E relative to MCT in pancreatic-insufficient CF but further studies are required to assess liposomal vitamin E (German Clinical Trial Register number DRKS00014295, funded from EU and Norsa Pharma).

Association between vitamin K1 intake and mortality in the Danish Diet, Cancer, and Health cohort.

Reported associations between vitamin K1 and both all-cause and cause-specific mortality are conflicting. The 56,048 participants from the Danish Diet, Cancer, and Health prospective cohort study, with a median [IQR] age of 56 [52-60] years at entry and of whom 47.6% male, were followed for 23 years, with 14,083 reported deaths. Of these, 5015 deaths were CVD-related, and 6342 deaths were cancer-related. Intake of vitamin K1 (phylloquinone) was estimated from a food-frequency questionnaire (FFQ), and its relationship with mortality outcomes was investigated using Cox proportional hazards models. A moderate to high (87-192 µg/d) intake of vitamin K1 was associated with a lower risk of all-cause [HR (95%CI) for quintile 5 vs quintile 1: 0.76 (0.72, 0.79)], cardiovascular disease (CVD)-related [quintile 5 vs quintile 1: 0.72 (0.66, 0.79)], and cancer-related mortality [quintile 5 vs quintile 1: 0.80 (0.75, 0.86)], after adjusting for demographic and lifestyle confounders. The association between vitamin K1 intake and cardiovascular disease-related mortality was present in all subpopulations (categorised according to sex, smoking status, diabetes status, and hypertension status), while the association with cancer-related mortality was only present in current/former smokers (p for interaction = 0.002). These findings suggest that promoting adequate intakes of foods rich in vitamin K1 may help to reduce all-cause, CVD-related, and cancer-related mortality at the population level.

Vitamin K Intake and Atherosclerotic Cardiovascular Disease in the Danish Diet Cancer and Health Study.

Background Dietary vitamin K (K1 and K2) may reduce atherosclerotic cardiovascular disease (ASCVD) risk via several mechanisms. However, studies linking vitamin K intake with incident ASCVD are limited. We aimed to determine the relationship between dietary vitamin K intake and ASCVD hospitalizations. Methods and Results In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study, with no prior ASCVD, completed a food-frequency questionnaire at baseline and were followed up for hospital admissions of ASCVD; ischemic heart disease, ischemic stroke, or peripheral artery disease. Intakes of vitamin K1 and vitamin K2 were estimated from the food-frequency questionnaire, and their relationship with ASCVD hospitalizations was determined using Cox proportional hazards models. Among 53 372 Danish citizens with a median (interquartile range) age of 56 (52-60) years, 8726 individuals were hospitalized for any ASCVD during 21 (17-22) years of follow-up. Compared with participants with the lowest vitamin K1 intakes, participants with the highest intakes had a 21% lower risk of an ASCVD-related hospitalization (hazard ratio, 0.79; 95% CI: 0.74-0.84), after multivariable adjustments for relevant demographic covariates. Likewise for vitamin K2, the risk of an ASCVD-related hospitalization for participants with the highest intakes was 14% lower than participants with the lowest vitamin K2 intake (hazard ratio, 0.86; 95% CI, 0.81-0.91). Conclusions Risk of ASCVD was inversely associated with diets high in vitamin K1 or K2. The similar inverse associations with both vitamin K1 and K2, despite very different dietary sources, highlight the potential importance of vitamin K for ASCVD prevention.

Menaquinone 4 Reduces Bone Loss in Ovariectomized Mice through Dual Regulation of Bone Remodeling.

Epidemiologic studies showed that higher vitamin K (VK) consumption correlates with a reduced risk of osteoporosis, yet the dispute remains about whether VK is effective in improving bone mineral density (BMD). We sought to discover the anti-osteoporotic effect of menaquinone-4 (MK-4) and evaluate the expression of critical genes related to bone formation and bone resorption pathways in the body. Fifty female C57BL/6 mice (aged 13 weeks) were randomly arranged to a sham-operated group (SHAM, treated with corn oil) and four ovariectomized groups that were administered corn oil (OVX group), estradiol valerate (EV, 2 mg/kg body weight as the positive control), low or high doses of VK (LVK and HVK; 20 and 40 mg MK-4/kg body weight, respectively) by gavage every other day for 12 weeks. Body and uterine weight, serum biochemical indicators, bone microarchitecture, hematoxylin-eosin (HE) staining, and the mRNA expression of critical genes related to bone formation and bone resorption pathways were assessed. Either dose of MK-4 supplementation increased the alkaline phosphatase (ALP), decreased the undercarboxylated osteocalcin (ucOC) and tartrate-resistant acid phosphatase (TRACP, p < 0.05) levels, and presented higher BMD, percent bone volume (BV/TV), trabecular thickness (Tb.Th), and lower trabecular separation (Tb.Sp) and structure model index (SMI, p < 0.05) compared with the OVX group. Additionally, both doses of MK4 increased the mRNA expression of Runx2 and Bmp2 (p < 0.05), whereas the doses down-regulated Pu.1 and Nfatc1 (p < 0.05) mRNA expression, the high dose decreased Osx and Tgfb (p < 0.05) mRNA expression, and the low dose decreased Mitd and Akt1 (p < 0.05) mRNA expression. These data show the dual regulatory effects of MK-4 on bone remodeling in ovariectomized mice: the promotion of bone anabolic activity and inhibition of osteoclast differentiation, which provides a novel idea for treating osteoporosis.

Effects of vitamin K2 supplementation on atherogenic status of individuals with type 2 diabetes: a randomized controlled trial.

BACKGROUND: This study was aimed to examine the effects of vitamin K2 supplementation on atherogenic status, assessed by insulin resistance (IR)-related indexes, in patients with type 2 diabetes mellitus (T2DM). METHODS: In this double-blind, controlled trial, 68 patients with T2DM on the oral glucose-lowering medications were randomly allocated into two groups receiving daily intakes of 360 µg MK-7 or placebo for 12 weeks. Eight different IR-related indexes were calculated at the baseline and end of the trial. RESULTS: At the end of the study, atherogenic coefficient (mean ± SD: - 0.21 ± 0.45 vs. 0.02 ± 0.43; p = 0.043), triglyceride-glucose index (8.88 ± 0.55 vs. 9.23 ± 0.69; p = 0.029), and atherogenic index of plasma (0.37 ± 0.27 vs. 0.51 ± 0.24; p = 0.031) were significantly lower in the vitamin K2 group, compared to the placebo. However, after accounting for their baseline values, the differences were no more significant. No significant differences were observed in Castelli's Ӏ and ӀӀ risk indexes, the ratio of triglycerides to high-density lipoprotein cholesterol, lipoprotein combine index, and the metabolic score for insulin resistance index between the two groups at the end of the study. CONCLUSIONS: Daily intakes of 360 µg vitamin K2 in the form of MK-7 for 12 weeks could not improve the IR-related indexes of Cardiovascular Diseases risk. TRIAL REGISTRATION: The trial was registered on Iranian Registry of Clinical Trials registry (Trial ID. IRCT20190824044592N1) on 22 December 2019. The record can be found at https://en.irct.ir/trial/41728 .

Supplementation with Octacosanol Affects the Level of PCSK9 and Restore Its Physiologic Relation with LDL-C in Patients on Chronic Statin Therapy.

Dietary supplementation with sugar cane derivates may modulate low-density lipoprotein cholesterol (LDL-C) and proprotein convertase subtilisin/kexin type 9 (PCSK9) levels. The purpose of this study was to determine if dietary supplement (DS), containing Octacosanol (20 mg) and vitamin K2 (45 µg), could restore the disrupted physiologic relation between LDL-C and serum PCSK9. Double-blind, randomized, placebo-controlled, single-center study including 87 patients on chronic atorvastatin therapy was conducted. Eighty-seven patients were randomized to receive DS (n = 42) or placebo (n = 45), and followed for 13 weeks. Serum PCSK9 levels, lipid parameters and their relationship were the main efficacy endpoints. The absolute levels of PCSK9 and LDL-C were not significantly different from baseline to 13 weeks. However, physiologic correlation between % change of PCSK9 and % change of LDL-C levels was normalized only in the group of patients treated with DS (r = 0.409, p = 0.012). This study shows that DS can restore statin disrupted physiologic positive correlation between PCSK9 and LDL-C. Elevated PCSK9 level is an independent risk factor so controlling its rise by statins may be important in prevention of cardiovascular events.

Effects of vitamin K2 combined with methotrexate against mitogen-activated peripheral blood mononuclear cells of healthy subjects and rheumatoid arthritis patients.

BACKGROUND: Methotrexate (MTX) is used as anchor drug for patients with early and established rheumatoid arthritis (RA). Vitamin K2 administration was also reported to be associated with decreased disease activity in RA. OBJECTIVES: Immunosuppressive pharmacodynamics of vitamin K2 combined with MTX was investigated. METHODS: Mitogen-activated peripheral blood mononuclear cells (PBMCs) were used to evaluate immunosuppressive pharmacodynamics of drugs in vitro. RESULTS: Vitamin K2 alone dose-dependently suppressed T cell mitogen-activated proliferation of PBMCs of both healthy subjects and RA patients. 446.5 and 2232.5 ng/mL vitamin K2 significantly decreased the IC50 values of MTX on the proliferation of PBMCs of RA patients, with little influences on the pharmacodynamics of MTX in the healthy PBMCs. 4465 ng/mL vitamin K2 potentiated the pharmacodynamics of MTX in both RA patients and healthy PBMCs. The additional effects of vitamin K2 to potentiate the suppressive effects of MTX seemed not to be related to the regulation of CD4+ CD25+ T cells or CD4+ CD25+ Foxp3+ Treg cells. MTX alone at 100 ng/mL significantly decreased the percentage of CD4+ T cells in PBMCs of healthy subjects (p < 0.001) with a slight influence in that of RA patients (not significant) and the combination did not show synergistic inhibitory effect. Vitamin K2 alone tended to suppress the secretion of IL-17, IFN-γ, and TNF-α from the activated PBMCs of RA patients with smaller influences on the cytokine productions from healthy PBMCs. These additional effects of vitamin K2 were also observed in combination with MTX. CONCLUSION: The above information may partially elucidate the potentiation effects of vitamin K2 on the immunosuppressive efficacy of MTX.

Vitamin K2 Awareness in Sun-Protected Patients Supplementing With Vitamin D.

Dermatologists often recommend vitamin D for sun-protected patients. Most patients are not aware of the key role vitamin K2 plays in vitamin D metabolism and do not receive sufficient dietary vitamin K2. A survey of 50 sun-protecting patients shows 4/50 understood the role of vitamin K2 and 1/50 was supplementing vitamin K2. Therefore, counseling on vitamin K2 supplementation may be of benefit to sun-protected dermatology patients. J Drugs Dermatol. 2021;20(2):228-229. doi:10.36849/JDD.5829.

Treatment to reduce vascular calcification in hemodialysis patients using vitamin K (Trevasc-HDK): A study protocol for a randomized controlled trial.

INTRODUCTION: End stage renal failure patients on hemodialysis have significant vascular calcification This is postulated to be related to sub-clinical vitamin K deficiency, which is prevalent in hemodialysis patients. Vitamin K deficiency result in the failure of the matrix GLA protein (MGP) to undergo carboxylation. MGP is a natural local inhibitor of vascular calcification and the lack of functional carboxylated MGP may contribute to increase vascular calcification. Vitamin K supplement should therefore correct this anomaly and decrease the rate or severity of vascular calcification in this population of patients on long-term maintenance hemodialysis. Our study seeks to evaluate the prevalence and the progression of vascular calcification in a cohort of maintenance hemodialysis patients. It will also evaluate the efficacy of vitamin K supplementation in reducing the progression of vascular calcification in this group of patients. METHODS: This will be a single-center randomized, prospective and open-label interventional clinical trial of end stage renal failure patients on hemodialysis. We aim to recruit 200 patients. Eligible patients will be randomized to either the standard care arm or active treatment arm. Active treatment arm patients will receive standard care plus supplementation with oral vitamin K2 isoform 360 mcg 3 times weekly for a total duration of 18 months. Primary outcome measured will be absolute difference in coronary artery calcification score at 18-month between control and intervention arms. Secondary outcomes will be to compare absolute difference in aortic valve calcification, percentage of patients with regression of coronary artery calcification of at least 10%, absolute difference in aortic and systemic arterial stiffness, mortality from any cause and major adverse cardiovascular over the same period. DISCUSSION: Evidence of successful regression or retardation of vascular calcification will support the conduct of larger and longer-term trials aimed at reducing cardiovascular disease mortality and major adverse cardiovascular events in this high-risk population using a safe and inexpensive strategy TRIAL REGISTRATION:: ClinicalTrials.gov NCT02870829. Registered on 17 August 2016 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02870829National University Hospital's Institutional Review Board (2015/01000).

Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate.

The world is desperately seeking for a sustainable solution to combat the coronavirus strain SARS-CoV-2 (COVID-19). Recent research indicated that optimizing Vitamin D blood levels could offer a solution approach that promises a heavily reduced fatality rate as well as solving the public health problem of counteracting the general vitamin D deficiency. This paper dived into the immunoregulatory effects of supplementing Vitamin D3 by elaborating a causal loop diagram. Together with D3, vitamin K2 and magnesium should be supplemented to prevent long-term health risks. Follow up clinical randomized trials are required to verify the current circumstantial evidence.

Vitamin K2 Needs an RDI Separate from Vitamin K1.

Vitamin K and its essential role in coagulation (vitamin K [Koagulation]) have been well established and accepted the world over. Many countries have a Recommended Daily Intake (RDI) for vitamin K based on early research, and its necessary role in the activation of vitamin K-dependent coagulation proteins is known. In the past few decades, the role of vitamin K-dependent proteins in processes beyond coagulation has been discovered. Various isoforms of vitamin K have been identified, and vitamin K2 specifically has been highlighted for its long half-life and extrahepatic activity, whereas the dietary form vitamin K1 has a shorter half-life. In this review, we highlight the specific activity of vitamin K2 based upon proposed frameworks necessary for a bioactive substance to be recommended for an RDI. Vitamin K2 meets all these criteria and should be considered for a specific dietary recommendation intake.

Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study.

Previous studies indicated a positive effect of vitamin K2 (VK2) supplementation on bone turnover biomarkers and bone mineral density (BMD), but the doses varied, and few studies have focused on the difference between VK2 supplementation alone and in combination with calcium and vitamin D3. The aim of this study was to explore a low and effective dose of VK2 for improving BMD, and to examine whether the co-supplementation of VK2, calcium and vitamin D3 would bring greater effects. In this trial, a total of 311 community-dwelling men and postmenopausal women aged 50 and 75 years were randomly assigned to four groups, receiving placebo, 50 µg/day, 90 µg/day or co-supplementation with calcium (500 mg/day) and vitamin D3 (10 µg/day) for 1 year. At the endpoint, the bone loss of femoral neck was significantly lower in postmenopausal women in the two 90 µg groups (treatment × time, p = 0.006) compared with placebo, but no effects in men. Serum biomarkers cOC/ucOC ratio increased in the intervention groups (treatment × time, p < 0.001). VK2 supplementation in dose of 90 µg/day performed a significant effect on reducing bone loss in postmenopausal women, but in combination with calcium and vitamin D3 brought no additional effects.Trial registration This trial was registered at http://www.chictr.org.cn as chiCTR1800019240.

Evaluation of synergistic combination comprising magnesium orotate, menaquinone-7, and cholecalciferol for management of type 2 diabetes and dyslipidemia.

Epidemiological outburst of type 2 diabetes is of great global concern. T2D starts with Insulin Resistance (IR) which arises largely due to environmental factors and to a lesser extent due to genetic factor. IR gradually develops into T2D and encompasses a wide array of conditions including Impaired Glucose Tolerance (IGT), hyperinsulinemia, Impaired Fasting Glucose (IFG), and Impaired Insulin Release (IIR). Initiation of IR increases the risk of Cardiovascular Diseases (CVD). Therefore, early diagnosis and management of IR and its related outcomes (hyperinsulinemia, hyperglycemia, and dyslipidemia) should be the prime focus of intervention therapies. Present research aimed to evaluate the synergistic combination of Magnesium orotate (MOD), Menaquinone- 7 (MK-7), and Cholecalciferol (CHOL) for the management of these therapeutic targets in the Streptozotocin-Nicotinamide-induced T2D Wistar rat model. Synergistic combination was found to be superior over its individual components in management of hyperglycemia, impaired insulin secretion, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and dyslipidemia (p < 0.01 or p < 0.05). Its effect was found to be equivalent or better than reference drugs (p < 0.01 or p < 0.05). Histopathological analysis depicted that combination treatment was able to regenerate and preserve pancreatic ß-cell mass in diabetic rats. In conclusion, combination studied in present research can be evaluated further under clinical settings for management of IR and its related outcomes.

Vitamin K2 protects PC12 cells against Aß (1-42) and H2O2-induced apoptosis via p38 MAP kinase pathway.

Alzheimer's is an age-related disease with a hallmark of progressive loss of memory formation followed by a damage in the brain function due to the neural degeneration and extracellular beta-amyloid (Aß) plaques accumulation. This study examines the protective effects of vitamin K2 on toxicity induced by (Aß) (1-42) and H2O2 in PC12 cells as an appropriate model of Alzheimer's cell damage. PC12 cells pretreated with vitamin K2 (5-200 µM) for 4, 24 and 48 h, and exposed to either Aß (25 µM) for 48 h or H2O2 (150 µM) for 24 h. Then the protective, antioxidant and anti-apoptotic effects of vitamin K2 in PC12 cells were investigated. Vitamin K2 pretreatment (5-200 µM) significantly decreased the Aß (1-42) and H2O2 cytotoxicity. In addition, vitamin K2 could attenuate reactive oxygen species (ROS) level after exposure of cells to H2O2 for 24 h and Aß (1-42) for 48 h. Cell apoptosis significantly increased following application of Aß (1-42) (25 µM) and H2O2 (150 µM) compared to control. However, flow cytometry histograms of PI-stained cells after pretreatment with vitamin K2 (20 and 50 µM) showed significantly reduced apoptosis. Vitamin K2 increased the amount of glutathione after exposure of cells to H2O2 for 24 h and Aß (1-42) for 48 h. Western blot analysis of PC12 cells showed that 25 µM Aß (1-42) and 150 µM H2O2 treatment could increase Bax, PARP cleavage, Phospho-p38 MAPK. Moreover, the activated form of caspase 3 proteins led to the reduction in the Bcl-2. Real-time PCR of PC12 cells showed that 150 µM H2O2 treatment increased the ratio of Bax/Bcl-2 while vitamin K2 (20 and 50 µM) reduced the rate. According to these findings, it seems that vitamin K2 possess anti-apoptotic and antioxidant effects and suggests that vitamin K2 may be a valuable protective candidate against the progression of Alzheimer's disease via inactivating p38 MAP kinase pathway.

Maximal dose-response of vitamin-K2 (menaquinone-4) on undercarboxylated osteocalcin in women with osteoporosis.

Low concentrations of serum vitamin K accompany high concentrations of undercarboxylated osteocalcin (ucOC) and osteoporotic fractures. Although vitamin K2 (MK-4) is approved as a therapeutic agent for the treatment of osteoporosis in some countries, the dose-response is unknown. The objective of this study was to assess the improvement in carboxylation of osteocalcin (OC) in response to escalating doses of MK-4 supplementation. A nine-week, open-labeled, prospective cohort study was conducted in 29 postmenopausal women who suffered hip or vertebral compression fractures. Participants took low-dose MK-4 (0.5 mg) for 3 weeks (until the second visit), then medium-dose MK-4 (5 mg) for 3 weeks (until the third visit), then high-dose MK-4 (45 mg) for 3 weeks. The mean ± SD age of the participants was 69 ± 9 years. MK-4 dose (p < 0.0001), but neither age nor other relevant medications (e.g. bisphosphonates) correlated with improvement in %ucOC. As compared to baseline concentrations (geometric mean ± SD) of 16.8 ± 2.4, 0.5 mg supplementation halved %ucOC to 8.7 ± 2.2 (p < 0.0001) and the 5-mg dose halved %ucOC again (to 3.9 ± 2.2; p = 0.0002 compared to 0.5-mg dose). However, compared to 5 mg/day, there was no additional benefit of 45 mg/day (%ucOC 4.6; p = NS vs. 5-mg dose). MK-4 supplementation resulted in borderline increases in γ-carboxylated osteocalcin (glaOC; p = 0.07). There were no major side effects of MK-4 supplementation. In postmenopausal women with osteoporotic fractures, supplementation with either 5 or 45 mg/day of MK-4 reduces ucOC to concentrations typical of healthy, pre-menopausal women.

Multicenter Randomized Controlled Trial of Vitamin K Antagonist Replacement by Rivaroxaban with or without Vitamin K2 in Hemodialysis Patients with Atrial Fibrillation: the Valkyrie Study.

BACKGROUND: Vitamin K antagonists (VKAs), although commonly used to reduce thromboembolic risk in atrial fibrillation, have been incriminated as probable cause of accelerated vascular calcification (VC) in patients on hemodialysis. Functional vitamin K deficiency may further contribute to their susceptibility for VC. We investigated the effect of vitamin K status on VC progression in 132 patients on hemodialysis with atrial fibrillation treated with VKAs or qualifying for anticoagulation. METHODS: Patients were randomized to VKAs with target INR 2-3, rivaroxaban 10 mg daily, or rivaroxaban 10 mg daily plus vitamin K2 2000 µg thrice weekly during 18 months. Systemic dp-ucMGP levels were quantified to assess vascular vitamin K status. Cardiac and thoracic aorta calcium scores and pulse wave velocity were measured to evaluate VC progression. RESULTS: Baseline dp-ucMGP was severely elevated in all groups. Initiation or continuation of VKAs further increased dp-ucMGP, whereas levels decreased in the rivaroxaban group and to a larger extent in the rivaroxaban+vitamin K2 group, but remained nevertheless elevated. Changes in coronary artery, thoracic aorta, and cardiac valve calcium scores and pulse wave velocity were not significantly different among the treatment arms. All cause death, stroke, and cardiovascular event rates were similar between the groups. Bleeding outcomes were not significantly different, except for a lower number of life-threatening and major bleeding episodes in the rivaroxaban arms versus the VKA arm. CONCLUSIONS: Withdrawal of VKAs and high-dose vitamin K2 improve vitamin K status in patients on hemodialysis, but have no significant favorable effect on VC progression. Severe bleeding complications may be lower with rivaroxaban than with VKAs.

[Clinical Pharmacometrics for Rational Drug Treatment].

Pharmacometrics is the mathematical study of pharmacokinetics, disease progression, and clinical outcomes. One objective of pharmacometrics is to facilitate rational drug treatment in patients, also termed clinical pharmacometrics. In this review, our clinical pharmacometric studies conducted over the last 10 years are discussed. Population pharmacokinetic analysis using therapeutic monitoring data for levetiracetam revealed that oral clearance allometrically scaled to both body weight and estimated glomerular filtration rate can accurately predict clinical data from patients of various ages (pediatric to elderly) with varying renal function. Dosage adjustments based on renal function in the package information are effective in controlling the trough and peak concentrations in similar ranges. In addition, a retrospective pharmacokinetic and pharmacodynamic study revealed that the efficacy of low-dose clobazam therapy was significantly influenced by CYP2C19 polymorphisms. Pharmacokinetic and pharmacodynamic models were successfully built using electronic medical information to explain retrospective international normalized ratio values of prothrombin time before and after catheter ablation in warfarin-treated patients. Simulation studies suggest that more than 20 mg of vitamin K2 is unnecessary in the preoperative period of catheter ablation. A physiologically based pharmacokinetic model adapted to tacrolimus pharmacokinetic data in patients who underwent living-donor liver transplantation was constructed, and clarified that oral clearance of this drug was affected by CYP3A5 genotypes in both the liver and intestine to the same extent. In conclusion, pharmacometrics is a useful methodology for individualized and optimized drug therapy.

Vitamin K2 immunosuppressive effect on pediatric patients with atopic dermatitis.

BACKGROUND: Over 20 kinds of steroids, tacrolimus ointments, and cyclosporine capsules are usually recommended for the treatment of atopic dermatitis (AD), depending on the symptoms of patients. However, several side effects sometimes occur with the extensive use of these agents for the treatment of pediatric AD patients. The purpose of this study was to explore whether vitamin K2 could be a new immunosuppressive candidate for pediatric patients with AD. METHODS: The immunosuppressive efficacy of vitamin K2 was evaluated through a cell-culture procedure using mitogen-activated peripheral blood mononuclear cells (PBMCs) obtained from pediatric AD patients. RESULTS: The mean (SD) IC50 value of vitamin K2 for the proliferation of concanavalin A-activated PBMCs was 15.37 (30.05) µmol/L, while the value for tacrolimus was 0.10 (0.28) ng/mL (0.12 (0.35) nmol/L). There was a significant correlation between the IC50 values for vitamin K2 and those for tacrolimus (P = 0.0001, r = 0.8871). However, there was no significant correlation between the IC50 values of vitamin K2 and those of cyclosporine A or methylprednisolone. A significant correlation between the IC50 values of vitamin K2 or tacrolimus and blood eosinophil counts (P = 0.0099, r = 0.7086 and P = 0.0032, r = 0.7722, respectively) was observed. CONCLUSION: Vitamin K2 -inhibited T-cell mitogen stimulated proliferation of PBMCs from pediatric AD patients in a dose-dependent manner. The PBMCs from pediatric AD patients were more sensitive to the immunosuppressive efficacy of vitamin K2 than the PBMCs from healthy subjects. The individual immunosuppressive pharmacological efficacy of vitamin K2 and of tacrolimus could be inferred from the blood eosinophil count of pediatric AD patients.

The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Vitamin K occurs in the diet as phylloquinone and menaquinones. Observational studies have shown that both phylloquinone and menaquinone intake might reduce cardiovascular disease (CVD) risk. However, the effect of vitamin K on vascular calcification is unknown. OBJECTIVES: The aim of this study was to assess if menaquinone supplementation, compared to placebo, decreases vascular calcification in people with type 2 diabetes and known CVD. METHODS: In this double-blind, randomized, placebo-controlled trial, we randomly assigned men and women with type 2 diabetes and CVD to 360 µg/d menaquinone-7 (MK-7) or placebo for 6 mo. Femoral arterial calcification at baseline and 6 mo was measured with 18sodium fluoride positron emission tomography (18F-NaF PET) scans as target-to-background ratios (TBRs), a promising technique to detect active calcification. Calcification mass on conventional computed tomography (CT) scan was measured as secondary outcome. Dephosphorylated-uncarboxylated matrix Gla protein (dp-ucMGP) concentrations were measured to assess compliance. Linear regression analyses were performed with either TBR or CT calcification at follow-up as the dependent variable, and treatment and baseline TBR or CT calcification as independent variables. RESULTS: We randomly assigned 35 patients to the MK-7 group (33 completed follow-up) and 33 to the placebo group (27 completed follow-up). After the 6-mo intervention, TBR tended to increase in the MK-7 group compared with placebo (0.25; 95% CI: -0.02, 0.51; P = 0.06), although this was not significant. Log-transformed CT calcification mass did not increase in the intervention group compared with placebo (0.50; 95% CI: -0.23, 1.36; P = 0.18). MK-7 supplementation significantly reduced dp-ucMGP compared with placebo (-205.6 pmol/L; 95% CI: -255.8, -155.3 pmol/L). No adverse events were reported. CONCLUSION: MK-7 supplementation tended to increase active calcification measured with 18F-NaF PET activity compared with placebo, but no effect was found on conventional CT. Additional research investigating the interpretation of 18F-NaF PET activity is necessary. This trial was registered at clinicaltrials.gov as NCT02839044.