Vitamin K2
Vitamin ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Directs calcium to bones and teeth while preventing arterial calcification. Critical partner for vitamin D3 supplementation.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Vitamin K2 is a vitamin most often used for bone health, cardiovascular health, calcium metabolism. NutriStack rates the overall evidence as strong. A typical adult dose is 100–200 mcg daily (MK-7), commonly taken as mk-7 (longer half-life) or mk-4 (faster acting). This profile indexes 19 sources.
The bottom line
Evidence rating strong. Most-documented uses: bone health, cardiovascular health, calcium metabolism. 19 sources indexed (2004–2024), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Activates osteocalcin (directs calcium into bone matrix) and matrix GLA protein (MGP, prevents calcium deposition in arteries and soft tissues) through gamma-carboxylation of glutamic acid residues.14,3
Dosing & protocol.
What it actually costs.
Real-world pricing across three quality tiers. Assumes Vitamin K2 MK-7.
Assumes about 90-200 mcg/day. MK-7 is usually the default K2 market and is moderately priced for a once-daily fat-soluble vitamin. Updated 2026-04-02.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Natto is the standout food source of MK-7.
Consistent natto intake is uncommon outside targeted diets.
Full safety detail.
Side effects
- Generally very well tolerated
- Rare allergic reactions
Contraindications
- Warfarin/blood thinners (consult doctor)
- Clotting disorders
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
3- 1Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: A systematic review and meta-analysis of randomized controlled trialsPMIDMa ML et al. · Front Public Health · 2022
16 RCTs with 6,425 subjects showed vitamin K2 significantly improved lumbar spine bone mineral density, particularly with combination therapy
- 2Efficacy and safety of vitamin K2 for postmenopausal women with osteoporosis at a long-term follow-up: meta-analysis and systematic reviewPMIDZhou M, Han S, Zhang W, Wu D · Journal of Bone and Mineral Metabolism · 2022
In 9 RCTs with 6,853 participants, VK2 significantly increased lumbar BMD (WMD 2.17, 95% CI 1.59-2.76) and forearm BMD (WMD 1.57, 95% CI 1.15-1.99). No serious adverse events related to VK2 supplementation were reported.
- 3The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trialsPMIDKuang X, Liu C, Guo X, Li K, Deng Q, Li D · Food & Function · 2020
Vitamin K combined with vitamin D significantly increased total BMD (pooled effect size 0.316, 95% CI 0.031-0.601) and significantly decreased undercarboxylated osteocalcin across 8 RCTs with 971 subjects.
Randomized controlled trials
10- 4No Detectable Coagulation Activation After Vitamin K (MK-7) Supplementation in Patients on Dialysis With Functional Vitamin K Deficiency: A One-Year Randomized, Placebo-Controlled StudyPMIDBladbjerg EM, Levy-Schousboe K, Frimodt-Møller M et al. · Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation · 2024
Bladbjerg EM, Levy-Schousboe K, Frimodt-Møller M et al.. 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. Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation. 2024
- 5Effect of Menaquinone-7 Supplementation on Arterial Stiffness in Chronic Hemodialysis Patients: A Multicenter Randomized Controlled TrialPMIDNaiyarakseree N, Phannajit J, Naiyarakseree W et al. · Nutrients · 2023
Naiyarakseree N, Phannajit J, Naiyarakseree W et al.. Effect of Menaquinone-7 Supplementation on Arterial Stiffness in Chronic Hemodialysis Patients: A Multicenter Randomized Controlled Trial. Nutrients. 2023
- 6The effect of vitamin MK-7 on bone mineral density and microarchitecture in postmenopausal women with osteopenia, a 3-year randomized, placebo-controlled clinical trialPMIDRønn SH, Harsløf T, Oei L et al. · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2021
Rønn SH, Harsløf T, Oei L et al.. 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. Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. 2021
- 7Multicenter Randomized Controlled Trial of Vitamin K Antagonist Replacement by Rivaroxaban with or without Vitamin K2 in Hemodialysis Patients with Atrial Fibrillation: the Valkyrie StudyPMIDDe Vriese AS, Caluwé R, Pyfferoen L et al. · Journal of the American Society of Nephrology : JASN · 2020
De Vriese AS, Caluwé R, Pyfferoen L et al.. 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. Journal of the American Society of Nephrology : JASN. 2020
- 8Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture at the tibia in postmenopausal womenPMIDKnapen MH et al. · Bone · 2016
MK-7 prevented age-related deterioration of trabecular bone microarchitecture at the tibia in healthy postmenopausal women over 3 years
- 9Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin gamma-Carboxylation: A Double-Blind, Randomized Controlled TrialsPMIDInaba N et al. · J Nutr Sci Vitaminol · 2015
Menaquinone-7 increased carboxylated/undercarboxylated osteocalcin ratio dose-dependently; daily intake >=100 mcg suggested for optimal gamma-carboxylation
- 10Vitamin K2 supplementation and arterial stiffness: a randomized controlled trialKnapen MH, Braam LA, Drummen NE et al. · Thromb Haemost · 2015
- 11Menaquinone-7 supplementation improves osteocalcin carboxylation and bone turnover markers in postmenopausal womenInaba N, Sato T, Yamashita T · J Bone Miner Metab · 2015
- 12Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding studyPMIDCaluwé R, Vandecasteele S, Van Vlem B et al. · Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association · 2014
Caluwé R, Vandecasteele S, Van Vlem B et al.. Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2014
- 13Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal womenPMIDKnapen MH et al. · Osteoporos Int · 2013
MK-7 supplementation significantly decreased age-related decline in bone mineral content and bone mineral density at femoral neck; also improved bone strength
Reviews & position papers
3- 14The Dual Role of Vitamin K2 in 'Bone-Vascular Crosstalk': Opposite Effects on Bone Loss and Vascular CalcificationPMIDMandatori D et al. · Nutrients · 2021
Vitamin K2 deficiency may be responsible for the 'calcium paradox', low calcium in bone and accumulation in vessel walls; K2 activates both osteocalcin and MGP
- 15Molecular Mechanism of Vitamin K2 Protection against Amyloid-β-Induced CytotoxicityPMIDHuang SH, Fang ST, Chen YC · Biomolecules · 2021
Huang SH, Fang ST, Chen YC. Molecular Mechanism of Vitamin K2 Protection against Amyloid-β-Induced Cytotoxicity. Biomolecules. 2021
- 16Synergistic effect of vitamin K2 and vitamin D3 on calcium metabolism: a reviewvan Ballegooijen AJ, Pilz S, Tomaschitz A et al. · Int J Endocrinol · 2017
Observational studies
1- 17High dietary menaquinone intake is associated with reduced coronary calcification: the Rotterdam StudyGeleijnse JM, Vermeer C, Grobbee DE et al. · J Nutr · 2004
Reference material
2- 18Tan J, Zhu R, Li Y et al.. Vitamin K2 in Managing Nocturnal Leg Cramps: A Randomized Clinical Trial. JAMA internal medicine. 2024Source linkedPMID
- 19Diederichsen ACP, Lindholt JS, Möller S et al.. Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial. Circulation. 2022Source linkedPMID
Common questions.
Quick answers about Vitamin K2, drawn from the data on this page.
What is Vitamin K2?
Directs calcium to bones and teeth while preventing arterial calcification. Critical partner for vitamin D3 supplementation.
What is Vitamin K2 used for?
Commonly cited benefits of Vitamin K2 include: Bone health; Cardiovascular health; Calcium metabolism. NutriStack rates the overall evidence as strong.
What is a typical dose of Vitamin K2?
A typical adult dose of Vitamin K2 is 100–200 mcg daily (MK-7). The commonly recommended form is MK-7 (longer half-life) or MK-4 (faster acting). These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Vitamin K2?
Reported side effects include generally very well tolerated, rare allergic reactions. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Vitamin K2?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Vitamin K2 in NutriStack.
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