Vitamin K2 for Bone Mineral Density
High-dose MK-4 (45 mg/day) reduced fractures in Japanese osteoporosis trials, but dose and population limit generalizability. MK-7 at nutritional doses shows improved bone markers and slower BMD decline in some trials.
Overview
Verdict
Japanese MK-4 trials show fracture reduction; MK-7 evidence is positive but thinner.
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- MK-7 180 mcg/day (nutritional) — MK-4 45 mg is pharmacologic and physician-supervised.
- Expected timeframe
- 12+ months.
Protocol
- form
- MK-7 for once-daily dosing; MK-4 trials used 45 mg/day in three divided doses
- duration
- 2-3 years before repeat DXA
- co factor
- Take with a fat-containing meal, alongside calcium, vitamin D and resistance training. Evidence is mixed and weaker for density than for bone quality. Vitamin K2 carboxylates osteocalcin, which binds calcium into the bone matrix. In trials the density signal is modest: Knapen found 180 mcg/day of MK-7 over 3 years preserved vertebral bone mineral content and bone strength indices in postmenopausal women, with limited effect on hip density, while the ECKO trial of vitamin K1 found no density benefit. Some Japanese MK-4 data show density preservation rather than gain, alongside fracture reduction.
- titration
- 180 mcg/day of MK-7 is the standard studied dose; higher has not shown added density benefit
- starting dose
- 180 mcg/day of vitamin K2 as MK-7 with a meal containing fat
Evidence
Effect of vitamin K on bone mineral density and fractures in adults: an updated systematic review and meta-analysis of randomised controlled trials
Mott A, Bradley T, Wright K +5 more
Apparent fracture benefits of vitamin K disappeared when analysis was restricted to higher-quality trials.
Vitamin K2 supplementation does not influence bone loss in early menopausal women: a randomised double-blind placebo-controlled trial
Emaus N, Gjesdal CG, Almås B +5 more
Vitamin K2 supplementation did not influence bone loss in early menopausal women over 12 months.
Vitamin K2 and bone health: a systematic review
Iwamoto, I., Kosha, S., Noguchi, S.
Review of vitamin K2 (menaquinone) trials, dominated by Japanese studies of high-dose MK-4 (45 mg/day), reported improved bone mineral density maintenance and reduced vertebral and non-vertebral fracture rates in postmenopausal and osteoporotic women, with effects on bone quality via osteocalcin carboxylation rather than density alone.
Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women
Knapen MH, Drummen NE, Smit E +2 more
MK-7 180 mcg/day decreased the age-related decline in lumbar spine and femoral neck bone mineral density.
Safety
Caveats
Warfarin interaction. Evidence strongest in K2-insufficient populations.
Less likely to help if
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.