Ved normale fysiologiske forhold udgøres kun 5 – 30% af de cirkulerende former af det intakte parathyreoideahormon (1- 84), mens 70 – 95% er til stede som carboxyterminale fragmenter.
Under normal physiologic conditions, full-length parathyroid hormone (1-84) constitutes only 5-30% of the circulating forms of the molecule, while 70-95% is present as carboxy-terminal fragments.