vitamin · for joint pain
Vitamin K2
Switches on a protein that keeps calcium in your bones and out of your joints.
Say that in clinical terms
Activates matrix Gla protein (MGP) which inhibits calcium deposition in cartilage and soft tissues, reducing joint calcification.
How strong is the research?
2 papers read, 2 supporting.
Who was studied: Studied in osteoarthritis. Joint pain from other causes was not tested.
How much to take
daily
90–180 mcg
Take with fat-containing meal for absorption. MK-7 has longer half-life than MK-4.
Before you take it
- No Tolerable Upper Intake Level (UL) has been established for any form of Vitamin K, including MK-7, by the Food and Nutrition Board; the NIH ODS states no adverse effects from food or supplemental Vitamin K have been reported in humans or animals.
- Warfarin/VKA contraindication: Vitamin K2 (MK-7) directly antagonizes the anticoagulant effect of vitamin K antagonists (warfarin, acenocoumarol, phenprocoumon) by restoring carboxylation of vitamin K-dependent clotting factors. MK-7's 72-hour biological half-life produces sustained, cumulative INR interference; even approximately 10 mcg/day has caused clinically significant INR reductions in approximately 40% of anticoagulated patients in dose-response research. MK-7 supplementation is considered contraindicated in patients on VKAs.
- Pregnancy: NIH ODS lists an Adequate Intake of 90 mcg/day for pregnant women without specific warnings for standard supplemental doses; however, high-dose MK-7 supplementation data in pregnant women has not been systematically characterized.
When to take it
Best taken: with food
What we make of it
The 440-patient trial we cite cannot be found, and the strong evidence is for a different form of vitamin K.
The detail
We could not locate the trial this rests on, despite repeated searches. The best evidence linking low vitamin K to knee arthritis measured K1, not MK-7 — so it does not support a claim about this specific form. The one MK-7 trial we could find was small and in rheumatoid arthritis, where it measured inflammation markers and disease activity rather than pain.