Research
Vitamin K2
182 peer-reviewed studies curated from PubMed and Semantic Scholar.
Studies
Sorted by quality and recency
The effect of vitamin K2 supplementation on bone turnover biochemical markers in postmenopausal osteoporosis patients: a systematic review and meta-analysis.
Systematic review and meta-analysis of randomized controlled trials on vitamin K2 supplementation in postmenopausal osteoporosis patients. Vitamin K2 improved bone turnover biomarkers, increasing osteocalcin and bone-specific alkaline phosphatase, and reducing undercarboxylated osteocalcin and tartrate-resistant acid phosphatase.
Habitual natto intake elevates serum MK-7 levels, enhances osteocalcin carboxylation, and supports bone density: a meta-analysis of Japanese evidence.
Meta-analysis of six studies involving 2,327 participants examining the effects of habitual natto consumption on serum MK-7 levels, osteocalcin carboxylation, and bone mineral density in Japanese populations. Natto intake is associated with elevated serum MK-7, increased carboxylated osteocalcin, decreased undercarboxylated osteocalcin, and modestly greater bone mineral density. The certainty of evidence is moderate for serum MK-7 and low for osteocalcin and BMD outcomes.
Vitamin K2 Supplementation and Clinical Outcomes in Hepatocellular Carcinoma Patients: A Meta-Analysis with Trial Sequential Analysis
Meta-analysis of 11 studies with 1,030 patients evaluating vitamin K2 supplementation in hepatocellular carcinoma (HCC) patients. Vitamin K2 significantly reduced disease recurrence and mortality at 1, 2, and 3 years without a significant increase in adverse events, suggesting good tolerability.
Effects of vitamin k2 and d3 supplementation on cardiac and systemic inflammation: a randomized controlled trial
The AVADEC randomized, double-blinded, placebo-controlled trial investigated the effects of high-dose vitamin K2 and D3 supplementation on cardiac and systemic inflammation in 388 high-risk elderly men over 24 months. Despite significant changes in dp-ucMGP indicating effective vitamin K2 supplementation, the vitamins did not significantly modify cardiac or systemic inflammation.
Effects of vitamin K2 and D3 supplementation on epicardial adipose tissue and systemic inflammation: A substudy of the AVADEC trial.
The AVADEC trial investigated the effects of vitamin K2 and D3 supplementation on epicardial adipose tissue (EAT) and systemic inflammation in 388 elderly men at cardiovascular risk over 24 months. Despite a significant reduction in dp-ucMGP, supplementation did not significantly affect EAT, PCAT, or systemic inflammation markers.
Effect of Menaquinone-7 (MK-7) Supplementation on Anthropometric Measurements, Glycemic Indices, and Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
This systematic review and meta-analysis evaluated the effects of Menaquinone-7 (MK-7) on anthropometric measurements, glycemic indices, and lipid profiles. The analysis showed that MK-7 had a desirable effect on glycemic control and total cholesterol, although further research is needed for a consistent conclusion.
Impact of Vitamin K supplementation on cardiovascular health outcomes associated with kidney disease – A systematic review and meta-analysis
Systematic review and meta-analysis of Vitamin K2 supplementation in CKD and ESKD patients, evaluating its effects on cardiovascular outcomes. No significant effect on arterial stiffness, vascular calcification, or cardiovascular mortality was found, though a modest reduction in all-cause mortality was noted. Larger trials are needed to confirm clinical benefits.
The effect of vitamin K supplementation on cardiovascular risk factors: a systematic review and meta-analysis.
Systematic review and meta-analysis of 17 RCTs investigating the effects of vitamin K supplementation on cardiovascular risk factors. Vitamin K supplementation significantly reduced HOMA-IR but had no significant effect on other outcomes such as anthropometrics, CRP, glucose metabolism, and lipid profile factors.
Study protocol of the InterVitaminK trial: a Danish population-based randomised double-blinded placebo-controlled trial of the effects of vitamin K (menaquinone-7) supplementation on cardiovascular, metabolic and bone health
The InterVitaminK trial is a randomised, double-blinded, placebo-controlled trial investigating the effects of vitamin K supplementation (menaquinone-7, MK-7) on cardiovascular, metabolic, respiratory, and bone health in a general ageing population with detectable vascular calcification. The primary outcome is progression of coronary artery calcification over 3 years, with secondary outcomes including bone mineral density, pulmonary function, and biomarkers of insulin resistance.
Effect of vitamin K2 in the treatment of nocturnal leg cramps in the older population: Study protocol of a randomized, double-blind, controlled trial
This study protocol outlines a randomized, double-blind, placebo-controlled trial to investigate the effects of vitamin K2 on nocturnal leg cramps (NLCs) in older adults. The trial will enroll 200 participants aged 65 and older, comparing vitamin K2 to placebo over 8 weeks, with primary outcomes focusing on the frequency of NLCs.
Efficacy and safety of vitamin K2 for postmenopausal women with osteoporosis at a long-term follow-up: meta-analysis and systematic review.
Meta-analysis and systematic review of 9 RCTs with 6853 participants assessing vitamin K2 supplementation in postmenopausal women with osteoporosis. Vitamin K2 was associated with increased lumbar and forearm BMD, decreased undercarboxylated osteocalcin, and increased osteocalcin. Higher adverse reaction rates were noted, but no serious adverse events were related to vitamin K2.
Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: A systematic review and meta-analysis of randomized controlled trials.
This meta-analysis of 16 RCTs with 6,425 subjects evaluated the effect of vitamin K2 on bone mineral density (BMD) and fracture incidence in postmenopausal women. VK2 significantly improved lumbar spine BMD and reduced fracture incidence after excluding one heterogeneous study. VK2 also reduced serum undercarboxylated osteocalcin levels and the ratio of uc-OC to cOC, indicating a positive effect on bone health.
Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial.
RCT of 365 elderly men with aortic valve calcification score >300 AU, testing MK-7 plus vitamin D supplementation for 2 years. The study found no significant effect on AVC progression, aortic valve area, or peak aortic jet velocity compared to placebo. However, a significant reduction in dp-ucMGP was observed with MK-7 plus vitamin D.
The effect of vitamin K2 supplementation on coronary artery disease in a randomized multicenter trial
This double-blinded randomized multicenter trial investigated the effect of vitamin K2 supplementation on coronary artery calcification (CAC) progression in 304 participants without known coronary disease. Over a 2-year follow-up, high-risk patients with CAC ≥400 AU had significantly lower progression of CAC in the intervention group. Vitamin K2 supplementation also significantly reduced the risk of AMI, revascularization, and all-cause death.
Vitamin K2 Supplementation for the Prevention and Treatment of Rheumatoid Arthritis
The paper investigates the effects of vitamin K2 supplementation on rheumatoid arthritis (RA). Study 1 found vitamin K2 inhibited proliferation of PBMCs in RA patients. Study 2 showed a decrease in RA clinical markers in the MK-7 treated group. Study 3 reported lower serum CRP and MMP-3 levels in the MK-4 treated group compared to the MK-4-naïve group. Vitamin K2 supplementation may benefit RA patients by reducing inflammation and improving disease activity.
Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study.
RCT of 311 middle-aged and elderly Chinese participants examining the effect of low-dose vitamin K2 supplementation on bone mineral density. The study found that 90 µg/day of vitamin K2 significantly reduced bone loss in postmenopausal women, but co-supplementation with calcium and vitamin D did not provide additional benefits.
Effect of Menaquinone-7 (vitamin K2) on vascular elasticity in healthy subjects: results from a one-year study
A randomized placebo-controlled trial in 243 vitamin K-insufficient subjects aged 40-70 years, testing the effect of menaquinone-7 (vitamin K2) on vascular elasticity over one year. MK-7 significantly decreased dp-ucMGP and cfPWV, with effects most pronounced in women, improving vascular characteristics, body weight, and BMI.
Vitamin K2 supplementation and the progression of abdominal aortic calcification in dialysis patients
This prospective, randomized, parallel group, multicenter trial will include 200 dialysis patients to assess the effect of vitamin K2 supplementation on the progression of abdominal aortic calcification. Patients will be randomized to receive either standard care or additional oral supplementation with menatetrenone (45 mg/day) for 24 months. The primary endpoint is the progression of abdominal aortic calcification, with secondary endpoints including bone mineral density and biomarkers associated with vitamin K and vascular calcification.
Association of vitamin K with cardiovascular events and all-cause mortality: a systematic review and meta-analysis.
Meta-analysis of 21 articles with 222,592 participants assessing the association between vitamin K and cardiovascular events and all-cause mortality. Higher dietary vitamin K consumption was associated with a moderately lower risk of coronary heart disease, while elevated plasma dp-ucMGP, a marker of vitamin K deficiency, was associated with increased risks of all-cause and cardiovascular mortality.
The efficacy and safety of menatetrenone in the management of osteoporosis: a systematic review and meta-analysis of randomized controlled trials.
Systematic review and meta-analysis of 18 RCTs evaluating menatetrenone in osteoporosis management. Menatetrenone decreased the ratio of undercarboxylated osteocalcin to osteocalcin and improved lumbar BMD compared with placebo, but its benefit in fracture risk control was uncertain. Menatetrenone increased the incidence of adverse events compared to placebo.
Menatetrenone for the treatment of osteoporosis.
Systematic review evaluating the effect of menatetrenone on osteoporosis in postmenopausal women, men, and glucocorticoid-treated patients. Evidence suggests a positive effect on bone mineral density and fracture prevention, particularly in postmenopausal women.
Vitamin K to prevent fractures in older women: systematic review and economic evaluation.
Systematic review and economic evaluation of vitamin K for preventing osteoporotic fractures in postmenopausal women. Phylloquinone (vitamin K1) showed a significant reduction in clinical fracture risk, while menatetrenone (vitamin K2) trials had mixed results. Vitamin K1 was found to be more cost-effective than some other treatments, but further research is needed to confirm its cost-effectiveness compared to alendronate.
The Effects of Vitamin K2 on Recovery from Muscle-Damaging Resistance Exercise in Young and Older Adults: The TAKEOVER Randomized Controlled Trial.
RCT assessing the effects of vitamin K2 supplementation on recovery from muscle-damaging exercise in young and older adults. No significant effects on muscle strength, physical function, or muscle soreness were found. However, age-specific effects on electromechanical delay, electromyography RMS, IL-6, and CK levels were observed, suggesting potential benefits in older adults.
Effects of One-Year Menaquinone-7 Supplementation on Vascular Stiffness and Blood Pressure in Post-Menopausal Women.
This study investigated the effects of one-year menaquinone-7 (MK-7) supplementation on vascular parameters in 165 pre-, peri-, and post-menopausal women with low vitamin K status. MK-7 supplementation significantly decreased dp-ucMGP plasma levels and attenuated vascular stiffness in post-menopausal women, with improvements in blood pressure and vascular markers.
#1671 Inhibiting progression of abdominal aortic calcification by vitamin K2 in dialysis patients
A 12-center, open-label RCT in Japan evaluated the impact of vitamin K2 on abdominal aortic calcification in 207 maintenance dialysis patients. The intervention group received 45 mg menatetrenone daily. Results showed that vitamin K2 administration significantly suppressed the progression of abdominal aortic calcification, independent of dietary vitamin K intake.
Vitamins K2 and D3 Improve Long COVID, Fungal Translocation, and Inflammation: Randomized Controlled Trial
RCT of 151 adults with long COVID comparing daily supplementation of 240 µg vitamin K2 and 2000 UI vitamin D3 to standard of care for 24 weeks. The vitamin K2/D3 group showed improvements in the RECOVER Long COVID Index, a decrease in the number of LC symptoms, and reductions in inflammatory and gut markers compared to the SOC group.
Vitamin K2: A promising new treatment for nocturnal leg cramps
A letter highlighting the potential role of Vitamin K2 in managing nocturnal leg cramps (NLCs). A placebo-controlled randomized clinical trial showed that Vitamin K2 significantly reduced cramp frequency, severity, and duration in people aged 65 and older with NLCs, with no adverse effects reported.
Adherence to dietary supplementation with menaquinone-7, a vitamin K2 analogue
The VitaK-CAC trial is a double-blind, randomized, placebo-controlled trial assessing adherence to supplementation with menaquinone-7 (MK-7) in patients with pre-existent coronary artery calcification. Adherence was estimated using pill counts, plasma levels of MK-7, and plasma levels of dp-ucMGP. Pill count adherence was 90%, while plasma level adherence was 80%.
Vitamin K2 in Managing Nocturnal Leg Cramps: A Randomized Clinical Trial.
This randomized clinical trial evaluated the effect of vitamin K2 supplementation on nocturnal leg cramps in older adults. The study found that vitamin K2 significantly reduced the frequency, intensity, and duration of nocturnal leg cramps compared to placebo, with no adverse events reported.
Efficacy of Recombinant Human Parathyroid Hormone 1–34 and Vitamin K2 Combination Therapy in Postmenopausal Osteoporosis
RCT comparing the efficacy and safety of recombinant human parathyroid hormone 1–34 and vitamin K2 combination therapy versus vitamin K2 alone in 77 postmenopausal osteoporosis patients. The combination therapy showed superior efficacy in improving bone mineral density and bone metabolism markers without a significant increase in adverse reactions.
No Detectable Coagulation Activation After Vitamin K (MK-7) Supplementation in Patients on Dialysis With Functional Vitamin K Deficiency: A One-Year Randomized, Placebo-Controlled Study.
This double-blinded, placebo-controlled study evaluated the effects of menaquinone-7 (MK-7) supplementation on coagulation biomarkers in 123 patients on dialysis over 52 weeks. The study found no detectable effects on biomarkers of coagulation activation or clot activities of vitamin K-dependent coagulation factors, indicating no procoagulant effects of MK-7 supplementation.
Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial.
RCT of 123 dialysis patients comparing MK-7 supplementation to placebo over 2 years. MK-7 accelerated BMD loss at the 1/3 distal radius but prevented lumbar spine BMD decline. Vitamin K status improved with MK-7, but findings do not support its use to preserve bone in dialysis patients.
Different vitamin K forms in hemodialysis patients: a simple dietary supplement to battle vascular calcification—randomized controlled trial
RCT comparing the efficacy and safety of vitamin K2 (MK-7) versus vitamin K1 (phytomenadione) on vascular calcification markers in 120 hemodialysis patients. MK-7 significantly increased active MGP levels compared to phytomenadione and placebo, suggesting it is more effective in modulating calcification regulators.
The additive effect of vitamin K supplementation and bisphosphonate on fracture risk in post-menopausal osteoporosis: a randomised placebo controlled trial.
This randomized placebo-controlled trial assessed the additive effect of vitamin K supplementation with bisphosphonate, calcium, and/or vitamin D on fracture risk in post-menopausal women with osteoporosis. While no significant differences in bone mineral density or bone turnover markers were observed, vitamin K supplementation led to modest improvements in hip geometry parameters.
Effect of Menaquinone-7 Supplementation on Arterial Stiffness in Chronic Hemodialysis Patients: A Multicenter Randomized Controlled Trial.
This multicenter randomized controlled trial evaluated the efficacy of menaquinone-7 (MK-7) supplementation on arterial stiffness in 96 chronic hemodialysis patients. While no significant difference was found in the overall change in carotid femoral pulse wave velocity (cfPWV) between the MK-7 and control groups, MK-7 significantly decreased cfPWV in patients with diabetes and lowered the rate of arterial stiffness progression.
Comparative Study Evaluating the Effect of the Administration of Vitamin K2 versus Placebo on Vascular Calcification in Haemodialysis Patients
RCT evaluating the effect of vitamin K2 (menaquinone, MK-7) supplementation on vascular calcification in 84 hemodialysis patients. The study found no significant difference in cardiovascular health markers between the vitamin K2 and placebo groups after 3 months.
Vitamin K2 supplementation improves impaired glycemic homeostasis and insulin sensitivity for type 2 diabetes through gut microbiome and fecal metabolites
A 6-month RCT on 60 T2DM participants with MK-7 (vitamin K2) intervention showed reductions in fasting serum glucose, insulin, and HbA1c levels. The study also involved microbiota transplantation in diet-induced obesity mice, showing improved glucose tolerance and increased concentrations of beneficial metabolites.
MO789: The Effect of Oral Vitamin K2 Versus K1 on Vascular Calcification in Hemodialysis Patients: A Randomized Controlled Trial
RCT of 120 hemodialysis patients comparing vitamin K1, vitamin K2, and placebo over 3 months. Vitamin K2 significantly increased MGP levels compared to vitamin K1 and placebo, indicating its superiority in improving a calcification inhibitor. No adverse effects were reported.
Fat-Soluble Vitamins in Standard vs. Liposomal Form Enriched with Vitamin K2 in Cystic Fibrosis: A Randomized Multi-Center Trial
A multi-center RCT comparing a liposomal fat-soluble vitamin formulation containing vitamin K2 with standard vitamin preparations in 100 pancreatic-insufficient cystic fibrosis patients. The liposomal formulation was superior in delivering vitamins D3 and E, improving vitamin K-dependent carboxylation, and potentially enhancing vitamin A status.
Effect of vitamin K2 administration on depression status in patients with polycystic ovary syndrome: a randomized clinical trial
This randomized, double-blind, placebo-controlled clinical trial assessed the effect of vitamin K2 (Menaquinone-7) on depression status in 84 women with PCOS. The intervention group received 90 µg/day Menaquinone-7 for 8 weeks, resulting in a significant improvement in depression status compared to placebo.
The effects of Vitamin K2 (menaquinone-7) on the leptin and adiponectin levels in overweight/obese type 2 diabetes patients: a randomized clinical trial
RCT of 60 overweight/obese T2DM patients evaluating the effect of 200µg/day MK-7 supplementation on adiponectin and leptin levels. MK-7 decreased fasting blood sugar and leptin levels, but had no significant effect on adiponectin or the adiponectin to leptin ratio.
The effect of menaquinone-7 supplementation on dp-ucMGP, PIVKAII, inflammatory markers, and body composition in type 2 diabetes patients: a randomized clinical trial.
This 12-week double-blind placebo-controlled RCT studied the effects of menaquinone-7 (MK-7) supplementation on serum dp-ucMGP, PIVKAII, inflammatory markers, and body composition in 60 type 2 diabetes patients. MK-7 supplementation significantly improved PIVKAII levels and reduced inflammatory markers, but did not significantly affect body composition indices.
Vitamin K2 (menaquinone-7) increases plasma adiponectin but does not affect insulin sensitivity in postmenopausal women: a randomized controlled trial.
RCT of 148 postmenopausal women receiving MK-7 375 µg daily or placebo for 12 months. MK-7 decreased serum undercarboxylated osteocalcin and increased plasma adiponectin but did not affect insulin sensitivity.
Safety and Efficacy of Vitamin K Antagonists versus Rivaroxaban in Hemodialysis Patients with Atrial Fibrillation: A Multicenter Randomized Controlled Trial
This multicenter randomized controlled trial compared the safety and efficacy of vitamin K antagonists (VKAs) versus rivaroxaban, with and without vitamin K2, in 132 hemodialysis patients with atrial fibrillation. The study found that rivaroxaban, both alone and with vitamin K2, significantly reduced the composite outcome of fatal and nonfatal cardiovascular events and major bleeding complications compared to VKAs.
The Use of Vitamin K2 in Patients With Parkinson's Disease and Mitochondrial Dysfunction (PD-K2): A Theranostic Pilot Study in a Placebo-Controlled Parallel Group Design
This pilot study investigates the effects of vitamin K2 (MK-7) in patients with Parkinson's disease and mitochondrial dysfunction. 130 participants, including mutation carriers, sporadic PD patients, and healthy controls, will receive MK-7 or placebo for 1 week. The study uses advanced neuroimaging and clinical assessments to evaluate treatment response.
Rationale for a Vitamin K2 and Vitamin D3 Intervention Trial in Children and Adolescents with Low-Energy Bone Fractures
Proposed RDBPC trial to investigate the effects of vitamin D3 with and without vitamin K2 (menaquinone-7, MK-7) on the healing of low-energy bone fractures in children and adolescents. The study will assess bone healing progress and blood levels of vitamins and bone turnover markers over three months.
Rationale for a Vitamin K2 and Vitamin D3 Intervention Trial in Children and Adolescents with Low-Energy Bone Fractures (Preprint)
This is a proposal for a three-month, randomized, double-blind, placebo-controlled trial investigating the effects of vitamin D3 with and without vitamin K2 (menaquinone-7) on the healing of low-energy bone fractures in children and adolescents. The study will involve 90 pediatric patients with low vitamin D levels, divided into three groups receiving vitamin D3, vitamin K2 with D3, or placebo. The trial aims to assess bone healing and turnover markers.
Effects of vitamin K2 supplementation on atherogenic status of individuals with type 2 diabetes: a randomized controlled trial.
This double-blind, controlled trial examined the effects of vitamin K2 supplementation on atherogenic status in 68 patients with type 2 diabetes. After 12 weeks of daily 360 μg MK-7 supplementation, no significant improvements were observed in insulin resistance-related indexes of cardiovascular disease risk compared to placebo.
Doppler Ultrasound Monitoring of Echogenicity in Asymptomatic Subcritical Carotid Stenosis and Assessment of Response to Oral Supplementation of Vitamin K2 (PLAK2 Randomized Controlled Trial)
This randomized controlled trial (PLAK2) evaluated the effect of oral vitamin K2 supplementation on carotid plaque composition in 60 patients with asymptomatic subcritical carotid stenosis. Patients were randomized to receive standard therapy with or without vitamin K2 for 12 months. The study found no significant differences in plaque echogenicity between the two groups, although vitamin K2 was associated with a greater monthly decline in GSM value for those with GSM reduction.
The impact of vitamin K2 and native vitamin D supplementation on vascular calcification in pediatric patients on regular hemodialysis. A randomized controlled trial.
RCT on 60 pediatric hemodialysis patients divided into four groups to assess the effects of vitamin K2 and native vitamin D on vascular calcification. Group 3, receiving both supplements, showed the most significant decrease in calcification markers dp-uc-MGP and uc-OC after 4 months, with no change in FGF23.
Effects of Combined Vitamin K2 and Vitamin D3 Supplementation on Na[18F]F PET/MRI in Patients with Carotid Artery Disease: The INTRICATE Rationale and Trial Design
The INTRICATE trial is a prospective double-blind placebo-controlled feasibility study assessing the influence of combined vitamin K2 and vitamin D3 supplementation on micro-calcification in carotid artery disease using Na[18F]F PET/MRI imaging. Fifty-two subjects with asymptomatic carotid artery disease will be randomized to receive either the vitamins or placebo, with primary and secondary endpoints focusing on changes in imaging and blood biomarkers.
Vitamin K Supplementation to Improve Vascular Stiffness in CKD: The K4Kidneys Randomized Controlled Trial.
RCT of 159 participants with CKD stage 3b or 4, comparing 400 μg oral vitamin K2 to placebo for a year. The study found no differences in pulse wave velocity, augmentation index, BP, or physical function, indicating no effect of vitamin K2 on vascular stiffness or vascular health.
The effect of vitamin MK-7 on bone mineral density and microarchitecture in postmenopausal women with osteopenia, a 3-year randomized, placebo-controlled clinical trial.
A 3-year randomized placebo-controlled trial in 142 postmenopausal women with osteopenia assessed the effects of vitamin K2 (MK-7) on bone mineral density and microarchitecture. The study found no significant differences in bone mineral density, bone turnover markers, or microarchitecture between the MK-7 and placebo groups, although MK-7 increased carboxylation of osteocalcin.
Effects of a novel nutraceutical combination (BruMeChol™) in subjects with mild hypercholesterolemia: study protocol of a randomized, double-blind, controlled trial
This study protocol describes a randomized, double-blind, placebo-controlled trial to evaluate the cholesterol and inflammation-lowering effects of BruMeChol™, a dietary supplement containing bergamot, olive fruit extracts, and vitamin K2, in subjects with mild hypercholesterolemia. The trial will assess changes in lipid profile and inflammatory biomarkers over 12 weeks.
Slower Progression of Arteriosclerosis in Maintenance Hemodialysis Patients with Menaquinone Supplementation: A Perspective Randomized, Placebo-Controlled Trial
This randomized, placebo-controlled trial investigated the effects of menaquinone (vitamin K2) supplementation on arteriosclerosis progression in 107 maintenance hemodialysis patients. After 9 months, the menaquinone group showed a significant reduction in inactive matrix Gla protein levels and a lower increment rate of carotid pulse wave velocity compared to the control group, suggesting a potential benefit in slowing arteriosclerosis progression.
Beneficial health effects of Menaquinone‐7 on body composition, glycemic indices, lipid profile, and endocrine markers in polycystic ovary syndrome patients
RCT of 84 PCOS patients comparing 90 µg Menaquinone-7 daily for 8 weeks to placebo. Menaquinone-7 significantly improved insulin resistance, lipid profile, body composition, and endocrine markers, suggesting beneficial effects for PCOS management.
Effects of MK-7 Supplementation on Glycemic Status, Anthropometric Indices and Lipid Profile in Patients with Type 2 Diabetes: A Randomized Controlled Trial
This double-blind placebo-controlled randomized clinical trial assessed the effects of menaquinone (MK-7) supplementation on glycemic indices, anthropometric indices, and lipid profile in 60 patients with type 2 diabetes. MK-7 supplementation significantly improved glycemic indices such as fasting blood sugar and HbA1c, but did not significantly affect the lipid profile.
Vitamin K-induced effects on body fat and weight: results from a 3-year vitamin K2 intervention study.
RCT of 214 postmenopausal women receiving 180 mcg/day of vitamin K2 (MK-7) or placebo for 3 years. MK-7 increased circulating carboxylated OC but had no effect on body composition overall. In 'good responders', MK-7 increased adiponectin and decreased abdominal fat mass and visceral adipose tissue area.
Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial.
A double-blind, placebo-controlled RCT investigated the effects of MK-7 (180 µg/day) supplementation on arterial stiffness in 244 healthy postmenopausal women over three years. MK-7 supplementation significantly decreased cfPWV and the Stiffness Index β, improving arterial stiffness, particularly in women with high baseline stiffness.
Vitamin K for the primary prevention of cardiovascular disease.
Systematic review including one small trial of 60 participants examining the effects of vitamin K2 (menaquinone, subtype MK7) on cardiovascular disease risk factors. The trial found no effects on blood pressure or lipid levels, and did not report on cardiovascular disease clinical events.
Dietary intake of vitamin K is inversely associated with mortality risk.
Prospective cohort analysis of 7216 participants from the PREDIMED study assessing the association between dietary vitamin K intake and mortality. Increased intake of phylloquinone or menaquinone was associated with a lower risk of cancer and all-cause mortality. Increased phylloquinone intake was also linked to reduced cardiovascular mortality risk.
Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women.
RCT of 244 healthy postmenopausal women receiving low-dose menaquinone-7 (MK-7) supplementation for 3 years. MK-7 significantly improved vitamin K status and decreased age-related decline in bone mineral density and bone strength at the lumbar spine and femoral neck.
Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study.
RCT with 200 chronic haemodialysis patients to determine the optimal dose of menaquinone-7 (MK-7) for MGP activation. Patients received 360, 720, or 1080 µg of MK-7 thrice weekly for 8 weeks. MK-7 supplementation dose-dependently reduced dp-uc-MGP levels, suggesting a potential approach to prevent vascular calcifications.
Vitamin K treatment reduces undercarboxylated osteocalcin but does not alter bone turnover, density, or geometry in healthy postmenopausal North American women.
Double-blind, placebo-controlled study of 381 postmenopausal women receiving phylloquinone, MK4, or placebo for 12 months. Phylloquinone and MK4 reduced serum undercarboxylated osteocalcin but did not alter bone turnover markers or bone mineral density. The study does not support vitamin K supplementation for osteoporosis prevention in this population.
Vitamin K2 supplementation does not influence bone loss in early menopausal women: a randomised double-blind placebo-controlled trial.
RCT among 334 postmenopausal Norwegian women assessing the effect of 360 microg MK-7 (vitamin K2) supplementation on bone mineral density changes. After 12 months, no statistical differences in bone loss rates were observed between the treatment and placebo groups, although serum levels of cOC increased and ucOC decreased in the treatment group.
[Vitamin K2].
Systematic review of seven Japanese RCTs showing that supplementation with Vitamin K2, particularly menaquinone-4, is associated with increased bone mineral density (BMD) and reduced fracture incidence in osteoporosis treatment.
Vitamin K2 supplementation improves hip bone geometry and bone strength indices in postmenopausal women
A randomized clinical intervention study among 325 postmenopausal women receiving either placebo or 45 mg/day of vitamin K2 (MK-4, menatetrenone) for three years. Vitamin K2 improved bone mineral content (BMC) and femoral neck width (FNW), contributing to maintaining bone strength, although it did not affect DXA-BMD.
Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials.
Systematic review and meta-analysis of randomized controlled trials assessing oral vitamin K supplementation (phytonadione and menaquinone) for bone health. The review found that vitamin K reduces bone loss and has a strong effect on reducing fractures, particularly among Japanese patients.
Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis.
A 24-month randomized open label study with 241 osteoporotic patients compared vitamin K2 treatment to a control group. The vitamin K2-treated group showed a lower incidence of clinical fractures and maintained lumbar bone mineral density better than the control group. Vitamin K2 treatment also enhanced gamma-carboxylation of the osteocalcin molecule.
Prevalence of Vitamin K2 Deficiency and Its Association with Coronary Artery Disease: A Case–Control Study
Case-control study comparing serum levels of vitamin K2 analogs (MK-4 and MK-7) in CAD patients and healthy controls. CAD patients, especially those with unstable angina, showed significantly lower levels of MK-4 and MK-7, suggesting a higher prevalence of vitamin K2 deficiency in this group.
Vitamin K2 Supplementation in Hospitalised COVID-19 Patients: A Randomised Controlled Trial
This single-centre, phase 2, double-blind, randomised, placebo-controlled trial investigated the effects of vitamin K2 supplementation in 40 hospitalised COVID-19 patients requiring supplemental oxygen. Vitamin K2 was well tolerated and decreased dp-ucMGP and PIVKA-II levels, reflecting improved vitamin K status, but did not show a protective effect against elastic fibre degradation.
Determination of Vitamin K1, MK-4, MK-7, and D Levels in Human Serum of Postmenopausal Osteoporosis Women Based on High Stability LC-MS/MS: MK-7 May Be a New Marker of Bone Metabolism
The study developed a new LC-MS/MS method to determine serum levels of VK1, MK-4, MK-7, and vitamin D in postmenopausal women with osteoporosis. MK-7 levels were found to decrease earlier than vitamin D in these patients, suggesting MK-7 as a potential biomarker for osteoporosis diagnosis.
Effect of vitamin K supplementation on serum calcification propensity and arterial stiffness in vitamin K-deficient kidney transplant recipients: A double-blind, randomized, placebo-controlled clinical trial.
Double-blind, randomized, placebo-controlled trial in 40 vitamin K-deficient kidney transplant recipients to assess the effects of vitamin K2 supplementation on serum calcification propensity and arterial stiffness. Vitamin K2 did not alter calcification propensity but prevented progression of arterial stiffness and improved vitamin K status.
The study of bioavailability and endogenous circadian rhythm of menaquinone-7, a form of vitamin K2, in healthy subjects
The study investigated the bioavailability and endogenous circadian rhythm of menaquinone-7 (MK-7) in healthy subjects through two randomised single-dose, open, one-way clinical trials. Results showed that MK-7 is absorbed with peak plasma concentrations at about 6 hours after intake and has a very long half-life, with no circadian rhythm observed.
VItamin K In PEritonial DIAlysis (VIKIPEDIA): Rationale and study protocol for a randomized controlled trial
The VIKIPEDIA trial is a randomized, open label, placebo-controlled study evaluating the effect of vitamin K2 supplementation on arterial stiffness and cardiovascular events in ESRD patients undergoing peritoneal dialysis. The trial will include 44 patients, assessing changes in pulse-wave velocity and other cardiovascular and metabolic endpoints over 1.5 years.
Vitamin K supplementation and arterial calcification in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial
The RenaKvit trial was a 2-year, double-blind, placebo-controlled study investigating the effect of vitamin K (menaquinone-7) supplementation on arterial calcification in 48 dialysis patients. Vitamin K supplementation improved vitamin K status but did not significantly affect the progression of arterial calcification compared to placebo.
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.
Multicenter RCT of 132 hemodialysis patients with atrial fibrillation comparing VKAs, rivaroxaban, and rivaroxaban plus vitamin K2 over 18 months. Vitamin K2 improved vitamin K status but did not significantly affect vascular calcification progression. Bleeding complications were lower with rivaroxaban than with VKAs.
The effect of vitamin K2 supplementation on vascular calcification in haemodialysis patients: a 1-year follow-up randomized trial.
A 1-year randomized trial in hemodialysis patients assessing the effect of oral vitamin K2 supplementation on vascular calcification. Vitamin K2 reduced serum uc-MGP levels but did not affect the progression of aortic calcification.
The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial.
RCT assessing the effect of 360 µg/d menaquinone-7 supplementation on vascular calcification in 68 patients with type 2 diabetes and CVD over 6 months. MK-7 tended to increase active calcification measured with 18F-NaF PET, but no effect was found on conventional CT. MK-7 significantly reduced dp-ucMGP levels compared to placebo.
Effect of Vitamin K2 on Postural Sway in Older People Who Fall: A Randomized Controlled Trial
RCT testing the effect of vitamin K2 supplementation on postural sway, falls, healthcare costs, and indices of physical function in older people at risk of falls. Vitamin K is thought to be involved in bone health and neuromuscular function.
Vitamin K2 supplementation and arterial stiffness among renal transplant recipients-a single-arm, single-center clinical trial.
The KING trial is a single-arm study evaluating the effect of menaquinone-7 (vitamin K2) supplementation on arterial stiffness in 60 renal transplant recipients. After 8 weeks, vitamin K2 supplementation was associated with a 14.2% reduction in arterial stiffness and a significant decrease in subclinical vitamin K deficiency.
Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture at the tibia in postmenopausal women.
RCT investigating the effect of MK-7 375 µg for 12 months on bone mineral density and microarchitecture in 148 postmenopausal women with osteopenia. The MK-7 group showed preservation of trabecular bone structure at the tibia compared to the placebo group, suggesting a protective effect against age-related deterioration.
Steady-state vitamin K2 (menaquinone-7) plasma concentrations after intake of dairy products and soft gel capsules.
RCT comparing plasma concentrations of MK-7 from yogurt enriched with MK-7 and other nutrients, yogurt fortified with MK-7 only, and MK-7 soft gel capsules over 42 days in healthy adults. The yogurt Kplus product showed a more pronounced increase in plasma MK-7, and all forms improved vitamin K status markers.
Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trials.
Two double-blind, randomized controlled trials investigated the effects of low-dose menaquinone-7 on osteocalcin γ-carboxylation in Japanese subjects. Study 1 involved 60 postmenopausal women consuming varying doses of menaquinone-7, while Study 2 involved 120 subjects comparing 100 μg menaquinone-7 to placebo. Menaquinone-7 intake increased the carboxylated osteocalcin/undercarboxylated osteocalcin ratio, suggesting improved bone health.
Menaquinone-7 Supplementation to Reduce Vascular Calcification in Patients with Coronary Artery Disease: Rationale and Study Protocol (VitaK-CAC Trial).
The VitaK-CAC trial is a double-blind, randomized, placebo-controlled trial designed to test the effects of menaquinone-7 (MK-7) supplementation on the progression of coronary artery calcification (CAC) in patients with coronary artery disease (CAD). The primary endpoint is the difference in CAC-score progression between the intervention and placebo groups over 24 months.
Vitamin K status in healthy volunteers.
The study measured markers of vitamin K status in 896 healthy volunteers and identified target groups for vitamin K supplementation. Two short-term trials on menaquinone-7 (MK-7, vitamin K2) supplementation in 42 children and 68 adults showed that those with more pronounced vitamin K deficiency had the highest responses to supplementation. Children and adults above 40 years may benefit from MK-7 supplementation to improve their extra-hepatic vitamin K status.
Pharmacokinetics of Menaquinone-7 (Vitamin K2) in Healthy Volunteers
The study investigated the pharmacokinetics of menaquinone-7 (MK-7, a form of vitamin K2) in healthy volunteers following a single intake from various formulations. Results showed that MK-7 absorption from capsules was faster than from tablets, and there was high intra- and inter-subject variability in absorption profiles.
Effects of risedronate alone or combined with vitamin K2 on serum undercarboxylated osteocalcin and osteocalcin levels in postmenopausal osteoporosis.
RCT of 101 postmenopausal women with osteoporosis comparing risedronate alone to risedronate combined with vitamin K2. The study evaluated serum ucOC, OC, and vertebral fracture incidence over 12 months. Decreased OC rates were higher in the risedronate group, while ucOC/OC change rates were lower compared to the combination group. Vertebral fracture incidence was not significantly different between groups.
The effect of menaquinone-7 supplementation on circulating species of matrix Gla protein.
A randomized, double-blind, placebo-controlled trial with 60 participants investigated the effect of menaquinone-7 (MK-7) supplementation on carboxylation of matrix Gla protein (MGP). MK-7 supplementation dose-dependently decreased desphospho-uncarboxylated MGP (dp-ucMGP) concentrations, indicating improved vitamin K status, but did not affect other MGP species or cardiovascular risk factors.
Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women.
The study compared the bioavailability of menaquinone-4 (MK-4) and menaquinone-7 (MK-7) in healthy Japanese women. MK-7 was well absorbed and increased serum levels significantly, while MK-4 was not detectable in serum and did not increase serum levels with consecutive administration.
Effect of vitamin K2 supplementation on functional vitamin K deficiency in hemodialysis patients: a randomized trial.
Interventional randomized trial with 53 hemodialysis patients assessing the effect of vitamin K2 (menaquinone-7) supplementation on functional vitamin K deficiency. Vitamin K2 supplementation induced a dose- and time-dependent decrease in circulating dephosphorylated-uncarboxylated MGP, uncarboxylated osteocalcin, and PIVKA-II levels, suggesting improved vitamin K-dependent protein bioactivity.
The effect of menaquinone-7 (vitamin K2) supplementation on osteocalcin carboxylation in healthy prepubertal children.
Double-blind randomized placebo-controlled trial examining the effect of 8 weeks of MK-7 supplementation on osteocalcin carboxylation in 55 healthy prepubertal children. MK-7 supplementation increased circulating concentrations of MK-7 and improved osteocalcin carboxylation, indicating enhanced vitamin K status.
Microbial vitamin biosynthesis links gut microbiota dynamics to chemotherapy toxicity
The study investigates the interaction between capecitabine and the gut microbiome in 56 colorectal cancer patients. It found that capecitabine treatment enriched menaquinol (vitamin K2) biosynthesis genes, which protected Escherichia coli from drug toxicity and was associated with decreased peripheral sensory neuropathy in patients.
Synergistic Optimization of Bacillus subtilis for Efficiently Producing Menaquinone-7 (MK-7) by Atmospheric and Room Temperature Plasma (ARTP) Mutagenesis and Metabolic Engineering
The study focuses on optimizing Bacillus subtilis for enhanced production of menaquinone-7 (MK-7) using Atmospheric and Room Temperature Plasma (ARTP) mutagenesis and metabolic engineering. Mutants with increased MK-7 production were developed, achieving a final titer of 239 mg/L, providing insights for future genetic modifications in MK-7 biosynthesis.
Combination of WEE1 Inhibitor and Vitamin K2 Enhances Therapeutic Efficacy in Chronic Myeloid Leukemia
The study investigated the combination of WEE1 inhibitors, particularly MK‐1775, with vitamin K2 in treating chronic myeloid leukemia (CML). The combination decreased colony growth, disrupted mitochondrial membrane potential, and increased cell death in CML cells, including those resistant to tyrosine kinase inhibitors.
Study on Fermentation Kinetics and Optimization of Feeding Strategy for Menaquinone-7 (Vitamin K2) Production by Bacillus Subtilis
The study investigated the fermentation process of Bacillus subtilis BS018 for menaquinone-7 (MK-7) production, a form of vitamin K2. A feeding strategy was developed and validated, showing increased MK-7 yield in bioreactors.
Production of Vitamin K2-7 from Soybean Using Bacterial Fermentation and its Optimization at Different Salt Concentrations
The study optimized the production of Vitamin K2-7 through submerged fermentation of soybean, varying time, temperature, and salt concentrations. Maximum production was achieved at 72 hours, 37°C, and a 1:1 salt ratio of CaCl2.2H2O to MgSO4.7H2O, enhancing production by 165% compared to fermentation without salts.
Evaluation of MENAQUINONE‐7 and fat‐soluble vitamin production by starter cultures during fermentation in dairy products using RPLC method
The study investigates the content of menaquinone-7 (MK-7) and other fat-soluble vitamins during the fermentation of various fermented milk products. The highest MK-7 content was found in kefir produced with kefir grain. The research highlights the potential of fermented products in nutritional recommendations.
Validation of bioanalytical method for quantification of Vitamin K2 (MK-4) in human plasma by high-performance liquid chromatography-ultraviolet
The study validated a bioanalytical method for quantifying Vitamin K2 (MK-4) in human plasma using high-performance liquid chromatography with ultraviolet detection. The method was shown to be selective, accurate, precise, and free from carryover, meeting the 2019 EMA guidelines.
Vitamin K1 and K2 in the Diet of Patients in the Long Term after Kidney Transplantation
Observational study evaluating the intake of vitamin K1 and K2 in the diet of 151 kidney transplant recipients. The study found adequate vitamin K1 intake but insufficient vitamin K2 intake, which is considered protective against vascular changes and bone lesions.