Carbonfiberboy 

That's for trying to lower the sedimentation rate associated with and symptomatic of RA. I don't see that having anything to do with increasing the activity of osteoblasts.

My rheumo gave me a quick course in bone. Bone is constantly in the process of renewal, called remodeling. Bones completely remodel themselves about every 10 years. So it's slow, but it happens, and happens in two separate processes: removal and replacement, called resorption and ossification. Reducing resorption and increasing ossification will strengthen bones.

My rheumo prescribed alandronate to reduce resorption. She said that while vitamin D deficiency reduces the activity of osteoblasts and thus ossification, the effect of more D beyond deficiency is basically unknown. She said that calcium supplements have been proven ineffective and are actually counterproductive, as they increase the risk of heart disease. It is thought that they are ineffective because the big calcium dump is cleared from the bloodstream so quickly. Calcium-containing food OTOH is effective. Cheese contains more calcium than one might think. Many vegetables contain calcium. Sardines with the bones are good. Etc. Look it up.

IGF-1 is associated with osteoblast activity, so anything that'll increase IGF-1 might help with ossification.

Anything that stresses your bones a lot helps with ossification, basically enough stress to equal about 10% of the breaking strength of the bone in question. So heavy weights and particularly plyometrics or anything where you pull big Gs on the bones in question. If I squat 225, that's only 2.5 Gs, not all that great, remembering that just standing there is 1 G. Jumping down from a height of 2' might create a 3.5g force. it's hard to calculate because the rate of deceleration is highly variable depending on shoes, surface, and knee flexion.

I doubt that walking or even usual running does much. Bone density in runners has been shown to be no better than in the sedentary. And cyclists are prime examples of athletic bone loss. That would be me.

That's all I know about it right now. My rheumo said to have another DEXA in 4-5 years.