Bone strength refers to the ability of our bones to withstand pressure and shocks without breaking or fracturing easily. It is an indicator of how healthy our bones are and how well they can support our body. Full definition
In combination with calcium and magnesium, they help increase bone strength as well. (blog.wellnessfx.com)
They are important for bone strength because of their ability to drive calcium into the tissues (i.e.: bone) from the blood. (robdaquila.com)
Vitamin K2 has also been shown to be an important factor in improving bone strength by binding calcium and other minerals to bone. (naturalhealth365.com)