Description
Calcitriol, also known as 1,25-dihydroxyvitamin D, is the biologically active form of Vitamin D. It is sometimes referred to as “active Vitamin D.” 25-Hydroxyvitamin D (25(OH)D) is converted into calcitriol in the kidneys through a process involving the enzyme 1-alpha-hydroxylase. This conversion is tightly regulated by parathyroid hormone (PTH), calcium levels, and phosphorus levels.
This test is not the same as 25-Hydroxyvitamin D (25(OH)D) which must be ordered separately.