Vitamin D, 1,25-Dihydroxy (Quest)


Vitamin D, 1,25-Dihydroxy Vitamin D. Also known as: 1,25-Dihydroxycholecalciferol, Vitamin D, 1,25-Dihydroxy. This test is frequently used to measure Vitamin D levels in the blood.

Test Description:
This test may be used when evaluating a Vitamin D deficiency or to evaluate parathyroid function or bone metabolism.

Detailed Information:
Vitamin D is certainly an important topic and news about Vitamin D can be found all over social media, health journals and commercials. The only way to know your vitamin D status is to test for it. There are two major metabolites of vitamin D: Vitamin D 25 OH and Vitamin 1, 25 – Dihydroxy. Vitamin D 1,25-Dihydroxy is the most potent of the various vitamin D metabolites. Its action stimulates calcium absorption in the intestine and its production is tightly regulated through concentrations of serum calcium, phosphorus, and parathyroid hormone.

Vitamin D is rapidly metabolized in the liver to form 25-hydroxy (OH) vitamin D. Additional hydroxylation of 25-OH vitamin D takes place in the kidney by 1-alpha hydroxylase, under the control of parathyroid hormone, to yield 1,25-dihydroxy vitamin D. Vitamin D 1,25-Dihydroxy levels are frequently decreased in hypoparathyroidism and in chronic renal failure.

Test Preparation for Optimal Results:
No fasting required.

Your health care provider should evaluate a deviation from normal ranges.