Menaquinone-7 in olive oil and bone protein changes in people
What it found
Taking olive oil enriched with menaquinone-7 raised its levels in the blood of 12 healthy adults.
The higher dose also shifted a bone protein into its active form.
What they found
Studies in people
Blood levels rose with dose
Plain olive oil did not change menaquinone-7 levels in the blood. Adding 45 mg or 90 mg of menaquinone-7 to the oil raised blood levels, and the higher dose produced a bigger rise.
Active bone protein increased
Only the 90 mg dose changed the bone protein osteocalcin. It raised the active form and lowered the inactive form in the blood of these 12 people.
Protein ratio tracked blood levels
The shift toward more active osteocalcin matched the rise in blood menaquinone-7 across all participants. The lower 45 mg dose raised blood levels but did not change the protein ratio.
Levels dropped after stopping
A two-week break from the enriched oil was enough to bring blood menaquinone-7 back down to starting levels in the volunteers.
What the authors conclude
- They suggest that regularly consuming olive oil enriched with menaquinone-7 may help maintain key processes involved in bone mineralisation.
- They note that only the higher 90 mg dose produced a measurable biological effect on the bone protein marker.
How it was done
Osteoporosis is a major problem as populations age, and vitamin K helps bones absorb calcium. The authors wanted to see if adding menaquinone-7 to olive oil could raise blood levels and support bone proteins.
Twelve healthy adults aged around 37 took part in a 56-day trial. They drank 20 ml of plain extra-virgin olive oil daily for two weeks, then olive oil with 45 mg of menaquinone-7 for two weeks, and finally olive oil with 90 mg after a break. Blood was drawn at each stage to measure menaquinone-7 and bone protein forms.
What it can’t tell you
- This trial lasted only two weeks per dose, so it cannot show long-term effects on actual bone strength or fracture risk.
- All 12 volunteers were young and healthy, so the results might differ in older adults or postmenopausal women who are more prone to bone loss.
Who paid
- Authors work at
- Polytechnic University of Marche, Italy
The paper
- Title
- Olive oil supplemented with menaquinone-7 significantly affects osteocalcin carboxylation
- Type
- Clinical trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Brugè F, Bacchetti T, Principi F, Littarru GP, Tiano L (2011). Olive oil supplemented with menaquinone-7 significantly affects osteocalcin carboxylation. The British journal of nutrition. doi:10.1017/S0007114511001425Free full textPubMed 21736837DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error