What is the studied dose of Vitamin K2 (MK-7)?

90–180 mcg/day of MK-7, typically taken alongside vitamin D3 and with a fat-containing meal for absorption. A studied dose is what research used, not a recommended dose.

What are the side effects of Vitamin K2 (MK-7)?

Very well tolerated at supplemental doses No established toxicity at typical supplemental intakes

Who should avoid Vitamin K2 (MK-7)?

Taking warfarin or another vitamin K antagonist without physician supervision; vitamin K directly opposes how these drugs work Pregnant or breastfeeding without clinician guidance

Vitamin

Vitamin K2 (MK-7)

A fat-soluble vitamin that activates the proteins directing calcium into bone rather than soft tissue. It is a foundational cofactor for vitamin D, not a cognitive ingredient, and it carries one significant caution: it directly interacts with warfarin and other vitamin K antagonists.

Grade CUpdated July 8, 2026Written and fact-checked in-house against The Evidence Standard. Not a clinical review.

Photo by Guilherme Simão on Pexels

Please note

Educational content, not medical advice. Doses below are ranges used in research, not recommendations. Talk to a qualified clinician before starting any supplement, especially if you take medication, are pregnant, or manage a health condition.

Evidence grade: Evidence: Grade C
Studied dose range: 90–180 mcg/day of MK-7, typically taken alongside vitamin D3 and with a fat-containing meal for absorption.
Time to effect: Not acute; vitamin K-dependent proteins (osteocalcin, matrix Gla protein) are carboxylated over weeks of consistent daily use.
Best form: MK-7 (menaquinone-7) over MK-4 or K1: MK-7 has a longer half-life and better-studied dosing in the trials above.

The short answer

Vitamin K2 (MK-7) (Vitamin) is studied for directing calcium toward bone alongside vitamin D (limited evidence) and foundational cofactor for a vitamin D3 regimen. In our conservative reading of the published human research, the evidence is Grade C (limited). 90–180 mcg/day of MK-7, typically taken alongside vitamin D3 and with a fat-containing meal for absorption. Not acute; vitamin K-dependent proteins (osteocalcin, matrix Gla protein) are carboxylated over weeks of consistent daily use. A studied dose is what trials used, not a recommended dose.

Full profile

Also known as	Menaquinone-7, MK-7, Menaquinone
Best for	Directing calcium toward bone alongside vitamin D (limited evidence) · Foundational cofactor for a vitamin D3 regimen · Not studied for cognition
Evidence grade	Grade C · Limited: early or small human trials
Studied dose range	90–180 mcg/day of MK-7, typically taken alongside vitamin D3 and with a fat-containing meal for absorption.
Time to effect	Not acute; vitamin K-dependent proteins (osteocalcin, matrix Gla protein) are carboxylated over weeks of consistent daily use.
Best form	MK-7 (menaquinone-7) over MK-4 or K1: MK-7 has a longer half-life and better-studied dosing in the trials above.
Food sources	Natto (fermented soybeans, by far the richest source), Hard and soft cheeses, Egg yolks, Chicken liver

Evidence, honestly graded

Claim-specific grading: for bone/working-with-D, a 2022 meta-analysis of 16 RCTs (Ma 2022, Frontiers in Public Health, PMID 36033779) found MK-7 supplementation has a positive effect on lumbar-spine bone mineral density in postmenopausal women, particularly combined with vitamin D or calcium. The evidence is real but the trial base is still limited and mixed, so this is graded C, not B. For the arterial-calcification/cardiovascular angle, the evidence is Emerging: a 2023 meta-analysis of 14 RCTs (Li 2023, Frontiers in Nutrition, PMID 37252246) found vitamin K supplementation slowed coronary-artery-calcification progression, and a 2023 RCT in older men (Hasific 2023, JACC Advances, PMID 38938724; the AVADEC trial, MK-7 720 mcg/day + vitamin D3) found no significant difference in the full study population but did find significantly slower CAC progression in a higher-risk subgroup with baseline CAC ≥400. That is a real, hypothesis-generating signal from one higher-risk-population RCT, not a confirmed effect. Replication in broader populations is needed before this claim could move past Emerging.

See the full grading rubric (study type, replication, population match, and dose adequacy) in The Evidence Standard.

1,720 natural health products with an active licence in Health Canada's LNHPD list Vitamin K2 (MK-7) as a medicinal ingredient.

That makes Vitamin K2 (MK-7) a recognized, licensable medicinal ingredient in Canada, regulated by Health Canada's Natural and Non-prescription Health Products Directorate, which issues each licensed natural health product a Natural Product Number (NPN). Search the LNHPD to verify.

Source: Health Canada Licensed Natural Health Products Database, snapshot 2026-09-28. A count of products with an active licence, not an endorsement of any health claim. This describes the ingredient's regulatory standing in Canada, not Signal State Core, which is a pre-launch concept and is not a licensed natural health product.

Side effects

Very well tolerated at supplemental doses
No established toxicity at typical supplemental intakes

Who should avoid it or check first

Taking warfarin or another vitamin K antagonist without physician supervision; vitamin K directly opposes how these drugs work
Pregnant or breastfeeding without clinician guidance

Interactions

Directly antagonizes warfarin and other vitamin K antagonist anticoagulants. Even low supplemental doses can meaningfully reduce their effect; anyone on these medications must not add vitamin K2 without physician and INR monitoring
May interact with other anticoagulant or antiplatelet therapy; discuss with a clinician

Stacks well with

Vitamin D3
Magnesium

Use caution stacking with

Warfarin or other vitamin K antagonist medication without physician supervision

What to look for on a label

State the form (MK-7 vs MK-4) and the microgram amount; 'vitamin K' alone does not specify which form or dose.
A product pairing D3 with K2 should carry a visible anticoagulant-interaction warning given how common warfarin and DOAC use is in the exact demographic (older adults) most likely to buy a bone-health product.

References

Ma 2022, Frontiers in Public Health: meta-analysis (16 RCTs). Vitamin K2 (MK-7) supplementation improved lumbar-spine bone mineral density in postmenopausal women, especially combined with vitamin D or calcium. PMID 36033779; doi:10.3389/fpubh.2022.979649. Primary basis for the C grade on bone/works-with-D. Educational, not a product claim.
Li 2023, Frontiers in Nutrition: meta-analysis (14 RCTs). Vitamin K supplementation had a significant effect on coronary-artery-calcification scores, slowing CAC progression. PMID 37252246; doi:10.3389/fnut.2023.1115069. Educational.
Hasific 2023, JACC Advances: AVADEC RCT. MK-7 (720 mcg/day) + vitamin D3 in 389 older men found no significant difference in CAC progression overall, but significantly slower progression in the higher-risk subgroup with baseline CAC ≥400. PMID 38938724; doi:10.1016/j.jacadv.2023.100643. Basis for the Emerging grade on the cardiovascular claim: hypothesis-generating, not confirmed.

Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.

Revision history

Every change to this ingredient's evidence status, dated and explained. The full cross-library log lives at Evidence Updates.

2026-07-08New profile
Initial profile published at Grade C: a 16-RCT meta-analysis supports bone and works-with-D roles in postmenopausal women, but the trial base is still limited and mixed.

See how Vitamin K2 (MK-7) compares on grade, dose, and goal in the Evidence Explorer.

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