K is the Key.
The latest science shows that high dietary intakes of vitamin K were associated with higher measures of bone mineral density, and higher scores in an ultrasound test.
There are two main forms of vitamin K: phylloquinone, (vitamin K1) which is found in green leafy vegetables such as lettuce, broccoli and spinach, and makes up about 90 percent of the vitamin K in a typical Western diet; and menaquinones (vitamins K2), which make up about 10 percent of Western vitamin K consumption. It is this second form (K2) which can be synthesised in the gut by microflora and is found in fermented food products like cheese and natto.
Source: Dietary vitamin K intake is associated with bone quantitative ultrasound measurements but not with bone peripheral biochemical markers in elderly men and women.