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What it is
A vitamin K supplement carrying the whole family — K1 plus K2 in both its MK-4 and MK-7 forms. Vitamin K is the cofactor the body uses to activate proteins like osteocalcin and matrix-Gla protein, the ones that direct calcium toward bone and away from soft tissue. Carrying all three forms covers both the fast-clearing (K1, MK-4) and the long-circulating (MK-7) members of the family.
Why the evidence supports it
Vitamin K's job is specific and well characterized: it switches on the calcium-handling proteins, and controlled trials of MK-7 show it measurably increases the active, carboxylated form of those proteins over months of use. That mechanism is why the full K family is favored over a single fraction — the forms clear at different rates and reach different tissues. Full circle, this is the cell's Build function: activating the proteins that guide calcium into the bone matrix rather than soft tissue. One real caution — vitamin K interacts with blood thinners, so anyone on those needs a doctor's sign-off first.
What it supports
- Supports the body's normal handling of calcium toward bone
- Supports healthy bone metabolism
- Works alongside vitamin D and calcium
- Provides the full K family (K1, MK-4, MK-7)
Which function it supports
Ties to the cell's Build function — vitamin K activates the proteins that guide calcium into bone rather than soft tissue.
Learn the why behind this pillarHow it relates to your cells and mind
Every product here ties back to a specific job your body does. This one touches the functions below — follow either link to see the mechanism in full, then dig into the studies.
What it is made of — and the mechanisms behind it
Each ingredient acts on several of the body's functions. Taken together, this product touches these cell and mind functions — follow any to see the mechanism in full.
The ingredients
Mechanisms drawn from our ingredient knowledge base (2 profiled ingredients). Structure and function only — not a treatment claim.
The science on the ingredients
Vitamin K professional fact sheetSystematic review2024
Summarizes vitamin K biology, coagulation-factor and osteocalcin/MGP carboxylation roles, and interaction with warfarin.
NIH Office of Dietary Supplements — NIH ODS fact sheet
Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women: double-blind randomised clinical trialEmergingRandomized controlled trial2015
Three years of daily MK-7 supplementation was associated with improved arterial stiffness measures in healthy postmenopausal women compared to placebo, most pronounced in those with stiffer arteries at baseline.
Knapen MHJ, Braam LAJLM, et al. — Thrombosis and Haemostasis
Phosphocalcic metabolism and the role of vitamin D, vitamin K2, and nattokinase supplementation.EmergingClinical trial2022
A clinical trial on Nattokinase found that vitamin K has been associated with a reduced risk of osteoporosis, cancer, and cardiovascular diseases (due to improved vascular elasticity).
Gasmi A; Bjørklund G; Peana M; Mujawdiya PK; Pivina L; Ongenae A; Piscopo S; Severin B — Critical reviews in food science and nutrition
Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women,Clinical trial2013
PMID 23525894.
Knapen MHJ, Drummen NE, Smit E, Vermeer C, Theuwissen E — Osteoporosis International
Vitamin K2 supplementation does not influence bone loss in early menopausal women,Clinical trial2010
334 women, MK-7 360mcg/day for 1 year; no significant difference in bone loss rate despite improved vitamin K status markers. PMID 20024657.
Emaus N et al. — Osteoporosis International
Low-Dose Daily Intake of Vitamin K2 (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled TrialRandomized controlled trial
Low-Dose Daily Intake of Vitamin K2 (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized Controlled Trial, PMID 26875489
Study authors — PMID 26875489
Molecular Pathways and Roles for Vitamin K2-7 as a Health-Beneficial Nutraceutical: Challenges and OpportunitiesExpert review2022
This review maps the molecular pathways through which the MK-7 form of vitamin K2 is thought to support tissues outside the liver.
Study authors — PubMed Central (PMC)
Relationship between Structure and Biological Activity of Various Vitamin K FormsExpert review2021
This review found that vitamin K1 and MK-4 clear from plasma within 8 to 24 hours, while longer-chain menaquinones like MK-7 can still be detected up to 96 hours later.
Study authors — PubMed Central (PMC)
Vitamin K2 Extends Lifespan by Alleviating Mitochondrial Stress via the JNK-1/SIR-2.1/DAF-16 Signaling Axis in Caenorhabditis elegans.2026
In C. elegans, low-dose vitamin K2 at 5 micromolar extended lifespan and improved stress resistance by maintaining mitochondrial morphology through the JNK-1/SIR-2.1/DAF-16 signaling axis, while higher doses were toxic.
Guo SY; Li YQ; Piao H; Zheng WF; Li SQ; Liu ZY; Lv JT; Kong Y; Li QF; Wang YZ; Li SZ; Zhao CL; Li S — Aging cell
Integrative approaches to perimenopause.2026
A review of perimenopause found that supplements including calcium, vitamin D, magnesium, and vitamin K2 are used to support bone health, alongside lifestyle and hormone-based approaches for symptom management.
Kennard A; Saunders KT — The American journal of medicine
Vitamin K2 Alleviates Insulin Resistance Associated Skeletal Muscle Atrophy via the AKT/mTOR Signalling Pathway.2025
In high-fat-diet mice and a 102-person trial with type 2 diabetes patients, vitamin K2 supplementation improved grip strength, muscle mass, and blood sugar control (HbA1c, HOMA-IR), working through activation of the AKT/mTOR pathway that promotes muscle protein synthesis.
Zhang Y; Wang Y; Ming Z; Li B; Qi H; Xie H; Wang G; Chen J; Duan L; Li R; Li Y — Journal of cachexia, sarcopenia and muscle
AS-IV Attenuates Oxidative Stress-Induced Apoptosis in Zebrafish via Modulation of the AKT/NRF2/HO-1/Caspase-3 Signaling Axis.2025
In zebrafish, Astragaloside IV reduced menadione-induced oxidative stress mortality and developmental abnormalities in a concentration-dependent manner via modulation of the AKT/NRF2/HO-1/Caspase-3 signaling axis.
Dai J; E Z; Bi Y; Yin Z; Wang Y; Wang X; Jia X; Zou B — Molecules (Basel, Switzerland)
Menaquinone-4 inhibits the formation and vulnerability of atherosclerotic plaques in apolipoprotein E knockout mice by decreasing the uptake of the oxidized low-density lipoprotein in macrophages.2025
In ApoE knockout mice, oral menaquinone-4 (vitamin K2) inhibited atherosclerotic plaque formation and stabilized existing plaques by reducing oxidized LDL uptake and foam cell accumulation in macrophages, without altering plasma cholesterol.
Yamada A; Koga M; Watase D; Hazekawa M; Harada M; Goto S; Setoguchi S; Matsunaga K — European journal of pharmacology
Unusual Plastoquinones in Non-Phototrophic Nitrifying Bacteria.2025
Isoprenoid quinones such as menaquinone, ubiquinone, and plastoquinone support electron and proton transport in respiratory and photosynthetic chains, and researchers found unusual plastoquinones in non-phototrophic nitrifying bacteria.
Bale NJ; Fujimura H; Pjevac P; Koenen M; Ikeda H; Itagaki S; Yamamoto Y; Palmetzhofer J; Sedlacek CJ; Palabikyan H; Sinninghe Damsté JS; Wagner M; Shiigi H; Daims H — Environmental microbiology reports
Menaquinone-4 ameliorates abdominal aortic aneurysm by suppressing ferroptosis through NRF2/GCLM axis.2025
In animal and cell models of abdominal aortic aneurysm, vitamin K2 (MK-4) reduced ferroptosis-driven vascular damage and helped preserve aortic structural integrity via the NRF2/GCLM pathway.
Zhou Z; Huang L; Wu D; He R; Zhou Y; Wang K; Wang R; Yao C — Gene
Engineering a PhrC-RapC-SinR quorum sensing molecular switch for dynamic fine-tuning of menaquinone-7 synthesis in Bacillus subtilis.2025
Researchers engineered a PhrC-RapC-SinR quorum-sensing molecular switch in Bacillus subtilis to dynamically fine-tune menaquinone-7 (vitamin K2) production, offering a gene-expression control strategy potentially applicable across many microorganisms.
Gao X; Luo Y; Adinkra EK; Chen Y; Tao W; Liu Y; Guo M; Wu J; Wu C; Liu Y — Microbial cell factories
Niallia tiangongensis sp. nov., isolated from the China Space Station.2025
Researchers characterized a novel spore-forming bacterium, Niallia tiangongensis, isolated from the China Space Station, identifying menaquinone-7 as its major quinone and structural protein differences that may enhance biofilm formation and radiation damage repair.
Yuan J; Zhang W; Dang L; Song Y; Yin Z; He Z; Xu K; Guo P; Yin H — International journal of systematic and evolutionary microbiology
ATP synthesis driven by atmospheric hydrogen concentrations.2025
Bacteria were shown to generate ATP using the membrane-associated enzyme Huc, which harnesses atmospheric hydrogen as an energy source to drive the proton gradient needed for ATP synthase.
Soom S; Moning SU; Cook GM; Lingford JP; Kropp A; Tran S; Grinter R; Greening C; von Ballmoos C — Proceedings of the National Academy of Sciences of the United States of America
Exploring Menatetrenone: Origin, Chemistry, Therapies and Delivery.2025
Menatetrenone (MK-4), a vitamin K2 form, is reviewed for therapeutic applications in osteoporosis, diabetes, and cardiovascular disease, with emerging evidence of anticancer and neuroprotective effects and new delivery systems improving its bioavailability.
Singh W; Kushwaha P; Kushwaha SP — Journal of the American Nutrition Association
Vitamin K2 protects against D-galactose induced ageing in mice.2025
In a D-galactose aging model, vitamin K2 (MK-7) reduced hippocampal oxidative markers and inflammatory cytokines, increased neuronal density, and was associated with improved memory performance in mice.
Chatterjee K; Mazumder PM; Banerjee S — European journal of pharmacology
Calcium, vitamin D, vitamin K2, and magnesium supplementation and skeletal health.2020
Narrative review finds calcium and vitamin D supplementation is key for managing osteoporosis, while evidence for vitamin K2 and magnesium improving bone quality and reducing fracture risk in osteoporotic patients remains inconclusive.
Capozzi A; Scambia G; Lello S — Maturitas
Safety and toxicological evaluation of a synthetic vitamin K2, menaquinone-7.2011
In toxicology studies, mice given a single 2000 mg per kg dose of vitamin K2 form MK-7 and rats given daily doses up to 10 mg per kg for 90 days showed no signs of toxicity at any dose tested.
Pucaj K; Rasmussen H; Møller M; Preston T — Toxicology mechanisms and methods
Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7.2007
In healthy adults, both synthetic vitamin K1 and natto-derived MK-7 were absorbed well, but MK-7 stayed in the blood far longer and drove more complete activation of the bone protein osteocalcin.
Schurgers LJ; Teunissen KJ; Hamulyák K; Knapen MH; Vik H; Vermeer C — Blood
Effect of vitamin K on bone mineral density: a meta-analysis of randomized controlled trialsEstablished2012
Pooled trial data showed vitamin K supplementation increased bone mineral density at the lumbar spine but produced no significant change at the femoral neck.
Fang Y, Hu C, Tao X, Wan Y, Tao F — Journal of Bone and Mineral Metabolism
Balanced by design — we show supporting and contradicting findings. Search all studies
No product works in isolation
Every cell function above — Sense, Exchange, Transform, Build, Maintain, Adapt — needs the same broad base of optimal micronutrient levels running underneath it, all the time. Purely-K is not a stand-alone fix; it is one piece that plugs into that larger system. The foundation comes first, and this supports it.
Stacks well with
Pick your goal — here is what Purely-K pairs with for each. Nothing works in isolation; these share the same systems.
For Bone & Cartilage
For Foundation Nutrition
Foundational, or targeted?
Not everything in the shop is meant to be taken forever. Some products here are foundational — a daily nutrient base built for long-term, ongoing use. Others are targeted -- shorter-term support for a specific season, not a lifelong habit. If you are not sure which one this is, that is a fair question to ask us before you buy.
Learn more, on your terms
Do not take our word for it — go read. Each topic below opens a pre-loaded search so you can explore the nutrient, the mechanism, or the device for yourself.
Search the full studies libraryHow to use it
Take with a meal that contains some fat, since vitamin K is fat-soluble. It pairs naturally with vitamin D at the same meal. If you take a blood thinner such as warfarin, do not start this without your doctor's guidance. Follow the label.
Use code HOLISTICLOVE at checkout.
Where to get it
We are lining up the best way to get this one to you. In the meantime, reach out and we will point you the right way — or browse the full shop to see every product.
See the full shopThe studies
See the research behind the science we point to.
Explore studiesThe blog
Plain-language reads on how it all fits together.
Read the blogOptimal nutrients are the definition of longevity
Long-term cell function depends on having what it needs, at the level it needs it, for as long as it needs it. That is the whole thesis behind everything we point you to here.
When you buy through our links, we earn a small commission — and that is what funds all the free education here. It never costs you more. Products are not intended to diagnose, treat, cure, or prevent any disease.
Purely-K carries the whole vitamin K family — K1 plus K2 in both MK-4 and MK-7 forms. Vitamin K is part of how the body activates the proteins that direct calcium where it belongs, toward bone. It fits people who want the full K family working alongside their vitamin D and calcium.
Common questions
What does Purely-K support?+
It supports the body's normal handling of calcium toward bone and healthy bone metabolism, works alongside vitamin D and calcium, and provides the full K family (K1, MK-4, MK-7).
How do I take it?+
Take with a meal that contains some fat, since vitamin K is fat-soluble. It pairs naturally with vitamin D at the same meal. If you take a blood thinner such as warfarin, do not start this without your doctor's guidance.
What makes it different?+
It carries the full K family rather than a single fraction. Vitamin K is a quiet nutrient that works alongside vitamin D and calcium, and most people rarely think about it.