What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
Vitamin K2 benefits: where the science stands
For bone: not settled yet.
Bone is what most people take vitamin K2 for, and the best studies disagree: four found it helps, four found no effect. As of August 2026, the verdicts on this page rest on evidence from 61 trials, drawn from the strongest research among the 297 papers on PubMed that mention vitamin K2. Every claim is checked below.
297 papers on PubMed · evidence from 61 trials
Claim by claim
- BoneThe science is still forming. The best studies disagree.
- Blood sugarThe science is still forming. The best studies disagree.
- CholesterolWell studied, and it does not work. Tested in 108 people.
- HeartThe science is still forming. The best studies disagree.
See 3 more scored claims+
- InflammationWell studied, and it does not work. Tested in 375 people.
- MoodThe science is still forming. Results lean positive, but there is not much yet.
- Strength and powerThe science is still forming. No real difference found so far.
Pairs people ask about
The 24 sources we read
- 2009Randomized trial · 40 people · benefit for bone; no clear effect on cholesterolsource
- 2010Randomized trial · 94 people · no clear effect on bonesource
- 2010Observational study · benefit for heartsource
- 2013Randomized trial · 244 people · benefit for bonesource
- 2015Randomized trial · 244 people · benefit for heart; no clear effect on inflammationsource
- 2015Meta-analysis · pools 1 trials, 60 people · no clear effect on heartsource
- 2020Meta-analysis · pools 9 trials · no clear effect on heartsource
- 2021Randomized trial · 142 people · no clear effect on bonesource
- 2021Randomized trial · 68 people · moderate benefit for blood sugar; no clear effect on cholesterolsource
- 2022Meta-analysis · pools 16 trials, 6,425 people · benefit for bonesource
- 2022Randomized trial · 365 people · no clear effect on heartsource
- 2022Randomized trial · 60 people · no clear effect on inflammationsource
- 2022Randomized trial · 84 people · benefit for moodsource
- 2023Randomized trial · 123 people · no clear effect on bonesource
- 2023Randomized trial · 105 people · no clear effect on bonesource
- 2023Randomized trial · 96 people · no clear effect on heartsource
- 2024Randomized trial · 68 people · no clear effect on heartsource
- 2024Meta-analysis · no clear effect on blood sugar; no clear effect on inflammationsource
- 2025Meta-analysis · pools 9 trials, 2,570 people · benefit for bonesource
- 2025Meta-analysis · no clear effect on cholesterolsource
- 2025Randomized trial · 165 people · benefit for heartsource
- 2026Randomized trial · 180 people · small benefit for heartsource
- 2026Randomized trial · 71 people · no clear effect on inflammation; no clear effect on strength and powersource
- 2026Meta-analysis · pools 8 trials · benefit for blood sugarsource
Chosen as the strongest evidence out of 297 papers on PubMed. Every row links to its paper.
Fair questions
Does vitamin K2 work?+
For bone, it is not settled. The best studies disagree.
Is vitamin K2 safe?+
No caution is recorded on this page. That is not a safety guarantee; the studies we read were not safety trials.
Why only 24 sources, when PubMed lists 297?+
The 297 is every paper that mentions vitamin K2 in any way: animal studies, blood measurements, papers where it is a side note. The strongest sources are combined reviews, and each one already gathers every trial its authors could find. Our 24 cover 61 trials between them, and every one is linked above. Both counts are measured, not estimated.