calcitonin

made from procalcitonin!!!
PTH has much stronger effect on serum calcium.

Net effect: ↓ serum calcium, basically the opposite of PTH
Secreted from parafollicular cells (C cells) of thyroid
Stimulus high serum calcium (via CaSR)
Inhibition
Acts on (action) see below
Action (function) see below

effects

Site Action
Bone ↓ osteoclast activity
↓ formation of new osteoclasts
Kidney ↑ excretion of Ca (and phosphate)
↑ production of calcitriol in kidney