Calcitriol acts directly on the parathyroid gland, regulating calcium receptor levels and directly inhibiting transcription of the gene encoding PTH. Calcitriol also has important secondary effects on PTH secretion.
What is the role of calcitriol in the body?
Calcitriol is in a class of medications called vitamin D analogs. It works by helping the body to use more of the calcium found in foods or supplements and regulating the bodys production of parathyroid hormone.
Where is calcitriol produced in the kidney?
Calcitriol is produced in the cells of the proximal tubule of the nephron in the kidneys by the action of 25-hydroxyvitamin D3 1-alpha-hydroxylase, a mitochondrial oxygenase and an enzyme which catalyzes the hydroxylation of 25-hydroxycholecalciferol (calcifediol). The activity of the enzyme is stimulated by PTH.