The treatment and effective phosphate binding, however, was proven and had an impact in the high phosphorus diet group: administration of this diet in vehicle treated animals resulted in hyperparathyroid bone disease as indicated by the substantial rise in osteoid area, osteoblast and osteoclast number and bone formation rate as well as a reduction of the bone area and trabecular number, in combination with higher serum PTH levels when compared to vehicle treated animals receiving the normal phosphorus dose. Here, PTH is linked to osteitis fibrosa.