Vitamin K2 (MK-7)
Fat-soluble vitamin involved in calcium handling. Often paired with vitamin D3.
Supplements
Research records
Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.
Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.
Vitamin K2 (MK-7)
Fat-soluble vitamin involved in calcium handling. Often paired with vitamin D3.
Evidence category: Systematic review. This describes the source category, not approval or certainty.
Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.
A meta-analysis of 16 randomised trials with 6,425 participants found vitamin K2 (MK-7) improved lumbar spine bone mineral density in postmenopausal women and lowered undercarboxylated osteocalcin. Fracture rates did not differ overall, though they were lower once one very different study was excluded. Reported adverse effects were no more common than in control groups. One randomised trial in 148 women with osteopenia found preserved trabecular bone structure at the tibia but no difference in bone density.
Benefits reported in the imported source
- Pooled randomised trials in 6,425 people found better lumbar spine bone density in postmenopausal women
- Undercarboxylated osteocalcin fell, and reported adverse effects were no more common than in controls
Risks and limits
- Fracture rates did not differ overall, and hip and femoral neck density did not change
- The lumbar gain appeared with combined therapy rather than K2 alone
- One trial preserved trabecular structure at the tibia but found no bone density difference
Source bottom line: Vitamin K2 improved some bone density and markers in postmenopausal women without reducing fractures.
Uncertainty: Reference information only. Not medical advice.
Study protocols — reports, not instructions
6,425 participants across 16 randomised trials, mostly postmenopausal women aged 50-80
- Reported regimen
- vitamin K2 as MK-4 or menatetrenone 45 mg a day, or MK-7 180-375 µg a day, alone or with other bone treatment
- Duration
- 6 to 48 months
- Reported outcome
- Undercarboxylated osteocalcin fell and lumbar spine density improved with combined therapy but not K2 alone; hip and femoral neck density and adverse events did not differ.
- Source
- Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: a systematic review and meta-analysis of randomized controlled trials (availability check 2026-10-15: possible access barrier; not independently inspected; HTTP 200)
Claim provenance
evidence.json#/catalog:supplement:vitamin-k2/protocols/0
148 postmenopausal women with osteopenia
- Reported regimen
- MK-7 375 µg a day against placebo, with calcium and vitamin D given to both groups
- Duration
- 12 months
- Reported outcome
- Trabecular number, spacing and thickness at the tibia were preserved against age-related deterioration, but bone mineral density did not differ at any site.
- Source
- Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture at the tibia in postmenopausal women (Rønn et al. 2016)
Claim provenance
evidence.json#/catalog:supplement:vitamin-k2/protocols/1
Community and practice descriptions
Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.
Historical research outcome: no-verified-description · 2026-10-06
No suitable community description was independently verified in these checks. The entry remains empty; this does not establish that no practice exists elsewhere. The excerpt concerns food and bacterial origins of menaquinones, not a community routine.
- https://nutritionsource.hsph.harvard.edu/vitamin-k/: no-practice-description — The excerpt concerns food and bacterial origins of menaquinones, not a community routine.
Pharmacokinetic context
No half-life recorded in this source snapshot. No value has been inferred.
Source references
- Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: a systematic review and meta-analysis of randomized controlled trials (availability check 2026-10-15: possible access barrier; not independently inspected; HTTP 200)
- Molecular Pathways and Roles for Vitamin K2-7 as a Health-Beneficial Nutraceutical: Challenges and Opportunities
- Vitamin K2 (menaquinone-7) prevents age-related deterioration of trabecular bone microarchitecture at the tibia in postmenopausal women (Rønn et al. 2016)
- NIH ODS: Vitamin K (availability check 2026-10-15: source not retrieved; HTTP 403)
Snapshot provenance
Source ID: catalog:supplement:vitamin-k2. Commit: adc7684614f9439b41d91a3312b62e7982c7e20e. Review state: historical-not-reverified. Authored links are retained separately from the canonical evidence links in the public data. App templates/defaults and rejected drafts are archived, not deployed.
Related entries and components
None listed.