Vitamin K2 (MK-4)
Also known as: Menaquinone-4, Menatetrenone
MK-4 is a form of vitamin K2 with a shorter time in circulation than MK-7. It appears in bone-wellness discussions, including research from Japan using much higher amounts than typical supplements provide. Evidence for common supplement doses is limited. Like other vitamin K forms, it is fat-soluble and relevant to clotting-pathway discussions.
Snapshot
Evidence level is outcome-specific; a supplement can have stronger evidence for one use and limited evidence for another.
What this page can tell you: Commonly discussed timing, food notes, caution categories, and an honest note on how much source review this entry still needs.
What it cannot: Whether this is appropriate for you personally, or that it treats, prevents, or cures any condition. Informational only — discuss with a clinician or pharmacist.
🕒 Timing
When: Morning, With a meal
Food: With a meal containing fat
Fat-soluble; commonly taken with a meal containing fat. Its shorter half-life is sometimes discussed as a reason for split dosing.
💊 Common use range
1–5 mg
Much higher amounts have been used in research settings under supervision; typical products use far less. Verify before assuming more is useful.
Ranges are informational, not a recommended dose. Talk to a professional about what is right for you.
⚠️ Commonly noted interactions (supplements)
None listed.
Often about absorption or timing rather than danger — separating doses is common. This list is not exhaustive.
🧭 Baseline caution
General caution for ordinary, common use — before accounting for your specific dose, medications, health history, or procedures.
No general caution factors flagged for ordinary use. See context alerts below for situations that may still apply to you.
Caution level is an informational summary of commonly discussed caution categories and doses — not a safety rating, approval, or medical advice. Low caution does not mean safe for you.
🔎 Context alerts to review
Context alerts may matter depending on your dose, medications, health history, or procedure plans — they do not mean the supplement is generally risky at ordinary use.
Medications
- Anticoagulant (blood thinner) interaction
🩺 Medication caution categories
- Blood thinners (anticoagulants) — The concern is an additive effect on bleeding, or a change in how the anticoagulant works — worth raising with your prescriber, especially before procedures.
🏥 Surgery & procedure caution
Because vitamin K affects clotting pathways, tell your care team before surgery, especially if you take blood thinners like warfarin.
If you have a procedure scheduled, bring your full supplement list to your surgical and anesthesia team. Do not stop prescribed medication unless your clinician tells you to. Do not start or stop supplements based only on this app.
✅ Quality checklist
- Prefer products with third-party testing or a certificate of analysis (COA).
- Check the label for the exact form and the elemental or active amount per serving.
🧩 Commonly paired with
🔁 Alternatives
🗣️ Questions for a professional
- I take (or may take) a blood thinner — should any form of vitamin K2 be avoided or kept consistent?
🔬 Evidence snapshot
Vitamin K acts as a cofactor for proteins involved in bone (osteocalcin) and vascular (matrix Gla-protein) biology, but evidence that K2 supplements improve bone mineral density or prevent fractures is mixed and inconclusive — some high-dose MK-4 studies suggested benefit while later trials did not. It is not established to treat osteoporosis. Intake guidance is an Adequate Intake (120/90 mcg), with no Tolerable Upper Intake Level.
🧪 Forms & quality
MK-4 is a menaquinone with a shorter side chain than MK-7. It is commonly discussed as clearing the blood faster, so products often use larger or more frequent doses. Neither form is simply 'better' — research differs by outcome.
See the supplement glossary for what form names like "L-", chelated, or standardized extract mean.
📏 Dose & monitoring
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
Evidence vs. burden: Not yet reviewed
😐 Commonly reported side effects
- Uncommon at typical doses
Non-exhaustive and individual.
🔄 Cycling & breaks
Cycling is not typically discussed; commonly used daily.
📅 Daily use notes
People on vitamin K–sensitive blood thinners should not add any K2 form without professional guidance.
📋 Source review status
Source-reviewed — last reviewed 2026-07-12
Reconciled 2026-07-12: NIH ODS Vitamin K fact sheet + MedlinePlus. Bone-supplement evidence mixed/inconclusive (no osteoporosis-treatment claim); critical warfarin interaction confirmed — keep vitamin K intake consistent and never start/stop without clinician oversight and INR monitoring.
📚 References
- NIH ODS — Vitamin K (Health Professional Fact Sheet)NIH ODS — K2 = menaquinones (MK-4, MK-7); carboxylates osteocalcin & matrix Gla-protein; supplement evidence for BMD/fractures mixed/inconclusive; AI 120/90 mcg, no UL; warfarin users must keep vitamin K intake consistent.
- MedlinePlus — Vitamin KMedlinePlus — Warfarin users may need to limit and keep vitamin K intake constant, since sudden changes alter the medicine's effect.
Verified against the source shown. See the research-status page for how review works.
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