Previous studies suggest that supplementation with vitamin K2 protects bone mineral density (BMD) and reduces fracture risk in older adults. The research is mostly on high doses of K2 MK-4, though; more evidence is needed for K2 MK-7.

The study

In this 12-month randomized controlled trial, 311 older adults (aged 50–75) were divided into four groups: 50 µg of MK-7, 90 µg of MK-7, 90 µg of MK-7 with 10 µg (400 IU) of vitamin D3 and 500 mg of calcium, or placebo.

The results

There wasn’t an improvement in any of the groups for lumbar spine BMD (the primary outcome), femoral neck BMD, and total hip BMD. There was a lesser loss in femoral neck BMD (but not lumbar spine BMD or total hip BMD) in postmenopausal women who took MK-7, especially the higher dose.


It’s likely that all of the minerals and vitamins relevant to bone health are needed for optimal bone mineralization. As it stands, all four groups had low levels of vitamin D throughout the trial, even the group that received vitamin D.

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This Study Summary was published on September 4, 2020.