Menaquinone-7 supplements in type 2 diabetes patients
What it found
In 45 people with type 2 diabetes, 12 weeks of menaquinone-7 (MK-7) supplements lowered one blood marker of vitamin K status, PIVKAII, compared with placebo.
The authors found no clear difference between groups for the other vitamin K marker, inflammation markers or body composition.
What they found
Studies in people
PIVKAII lowered
After 12 weeks, the vitamin K marker PIVKAII fell significantly in the MK-7 group but not in the placebo group. After adjusting for starting levels and changes in vitamin K intake, this difference between groups remained significant.
dp-ucMGP unclear
The other vitamin K marker, dp-ucMGP, also fell significantly in the MK-7 group over the study. But after adjusting for starting levels and changes in vitamin K intake, the difference between the MK-7 and placebo groups was not significant.
Inflammation markers
Levels of hsCRP, IL-6 and TNF-α were significantly lower within the MK-7 group after 12 weeks, but not in the placebo group. However, the differences between the two groups were not statistically significant.
Body composition
Body fat percentage, fat mass, fat free mass, muscle mass, bone mass and total body water did not differ significantly between the groups or across the trial.
Diet and vitamin K intake
Calorie and macronutrient intake were similar between groups before and after the study. Dietary vitamin K intake increased significantly in both groups over the study, but the difference between groups was not significant.
What the authors conclude
“Although further studies are needed, it appears that MK-7 supplementation can be effective in improving PIVKAII levels, but not for improving dp-ucMGP, inflammatory status or the body composition indices of T2DM patients.”
Also in their conclusions
- They conclude that MK-7 supplementation led to improvements in serum levels of PIVKAII in T2DM patients.
- They say that the effectiveness of MK-7 for improving dp-ucMGP levels, inflammatory status and body composition indices requires further research, as there were no statistically significant differences between the two groups.
- They suggest that MK-7 may be a potentially useful adjunctive treatment for T2DM patients, if the results are confirmed in future research.
How it was done
Type 2 diabetes involves ongoing high blood sugar and inflammation, which make each other worse. Diabetes is also recognised as a risk factor for vitamin K deficiency, and the authors wanted to test whether MK-7 supplements could help.
They ran a 12-week double-blind placebo-controlled randomised trial in Tabriz, Iran, with 60 type 2 diabetes patients aged 20 to 55. Patients were split equally into a group taking 200 mcg/day of MK-7 or a placebo, and all received dietary advice. In total 45 patients completed the trial (23 in the MK-7 group and 22 in the placebo group).
What it can’t tell you
- This trial was small and 15 of the 60 patients dropped out, so the results may not reflect what would happen in a larger group.
- The study lasted only 12 weeks, so it cannot show whether longer use would change the results.
- The authors note they do not know how strictly participants followed the dietary advice, which could affect the findings.
Who paid
- Conflicts
- The authors declare no competing interests.
- Authors work at
- Tabriz University of Medical Sciences, Iran; University of Nicosia, Cyprus
The paper
- Title
- The effect of menaquinone-7 supplementation on dp-ucMGP, PIVKAII, inflammatory markers, and body composition in type 2 diabetes patients: a randomized clinical trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Karamzad N, Faraji E, Adeli S, Sullman MJM, Pourghassem Gargari B (2022). The effect of menaquinone-7 supplementation on dp-ucMGP, PIVKAII, inflammatory markers, and body composition in type 2 diabetes patients: a randomized clinical trial. Nutrition & diabetes. doi:10.1038/s41387-022-00192-5Free full textPubMed 35365594DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error