On the other hand, calcitonin is produced by the thyroid gland in response to high serum calcium, so it opposes the action of PTH - therefore promoting bone formation and decreasing bone resorption.

另一方面，当血清中钙含量较高时，甲状腺释放降血钙素，来制约甲状旁腺激素的作用，从而促进骨骼的形成并减缓骨骼的吸收。

Bone remodelling as a whole is highly dependent on serum calcium levels, which, in turn, are kept in the normal range by a balance between parathyroid hormone, or PTH, calcitonin and vitamin D.

整个骨重建进程高度依赖于血清中钙的含量，而将血清中钙的含量维持在正常值范围内是由甲状旁腺激素、降血钙素与维生素D间的制约平衡所控制的。