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evidence · mechanism · dose
Supplements/Vitamin

Vitamin K2 (MK-4)

Short-acting K2 form used at high dose in Japanese osteoporosis protocols.

Bone Health

Overview

Short-acting K2 form used at high dose in Japanese osteoporosis protocols.

Natural sources
    Common forms

      Forms & variants of Vitamin K2 (MK-4)

      Different chemical forms of Vitamin K2 (MK-4) behave differently. Browse each form's mechanism, bioavailability, and best-use context.

      MK-7 (Menaquinone-7)
      Vitamin K2 (MK-7)

      Long-half-life K2 — directs calcium to bone and away from arteries.

      Mechanism of action

      Same carboxylation cofactor as MK-7 but shorter half-life; tissue-specific accumulation.

      Pathways

        Effects on the body

        Organ system effects

        Evidence-based benefits

        Reduces vertebral fractures at 45 mg/d (Japanese trials)

        Moderate evidence

        Potential side effects

        Common
          Rare
            Serious

              Drug interactions

              Warfarin
              Antagonizes warfarin.
              severe

              Supplement interactions

              Pairs well with

              None listed.

              Avoid combining with

              No specific avoidances listed.

              Dosing & bioavailability

              Typical dose
              45 mg/d (Japanese protocol)
              Study range
              1.5–45 mg
              With food?
              With fat

              Where to buy

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              Thorne
              Practitioner-grade · NSF tested

              Scientific evidence (8)

              Systematic reviewNutr Res · 2009

              MK-4 for osteoporosis in postmenopausal women

              Iwamoto J, et al.

              Review of MK-4 in osteoporosis (Japan).

              Key findings

              Reduced fracture risk at pharmacologic doses (45 mg/d).

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — Reduces vertebral fractures at 45 mg/d

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) Reduces vertebral fractures at 45 mg/d" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "Reduces vertebral fractures at 45 mg/d". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — randomized controlled trial

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) randomized controlled trial" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — meta-analysis

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) meta-analysis" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — pharmacokinetics

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) pharmacokinetics" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "pharmacokinetics". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — safety adverse events

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) safety adverse events" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "safety adverse events". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewPubMed (NLM) · 1970

              PubMed: Vitamin K2 (MK-4) — dose response

              Live PubMed search

              Live results for "Vitamin K2 (MK-4) dose response" across the PubMed/MEDLINE peer-reviewed index.

              Key findings

              Opens current human and preclinical literature matching Vitamin K2 (MK-4) and "dose response". Filter by RCT, meta-analysis, or year on the results page.

              Open study
              Systematic reviewGoogle Scholar · 1970

              Google Scholar: Vitamin K2 (MK-4) — clinical evidence

              Live Scholar search

              Cross-database citation index for Vitamin K2 (MK-4) as it relates to "clinical evidence".

              Key findings

              Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.

              Open study
              Educational use only. This profile is not medical advice. Consult a qualified healthcare professional before starting any supplement, especially if you take prescription medication or have a chronic condition.