Vitamin D, 25-Hydroxyvitamin D (D2, D3), LC/MS/MS (QuestAssureD™) Most Popular

The Vitamin D, 25-Hydroxyvitamin D (D2, D3), LC/MS/MS (QuestAssureD™) test contains 1 test with 4 biomarkers.

Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. Lower than normal 25-OH vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver. A 25-OH vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead hypercalcemia. This assay employs liquid chromatography tandem mass spectrometry to independently measure and report the two common forms of 25-hydroxy vitamin D: 25OH D3 - the endogenous form of the vitamin and 25OH D2 - the analog form used to treat 25OH Vitamin D3 deficiency.

The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.

Vitamin D, 25-Oh, D2

Vitamin D2 ((ergocalciferol,) is found in fortified foods and in most vitamin preparations and supplements. Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. The D2 form is found in fortified foods and in most vitamin preparations and supplements. Vitamin D2 is effective when it is converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.

Vitamin D, 25-Oh, D3

Vitamin D3 (cholecalcifero) which comes from animals. Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. Vitamin D3 is the form produced in the body and is also used in some supplements. Vitamin D3 are is converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.

Vitamin D, 25-Oh, Total

Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. The chemical structures of the types of vitamin D are slightly different, and they are named vitamin D2 (ergocalciferol, which comes from plants) and vitamin D3 (cholecalciferol, which comes from animals). The D2 form is found in fortified foods and in most vitamin preparations and supplements. Vitamin D3 is the form produced in the body and is also used in some supplements. Vitamin D2 and D3 are equally effective when they are converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.

Vitamin D, 25-Oh, Total

Vitamin D comes from two sources: endogenous, which is produced in the skin on exposure to sunlight, and exogenous, which is ingested in foods and supplements. The chemical structures of the types of vitamin D are slightly different, and they are named vitamin D2 (ergocalciferol, which comes from plants) and vitamin D3 (cholecalciferol, which comes from animals). The D2 form is found in fortified foods and in most vitamin preparations and supplements. Vitamin D3 is the form produced in the body and is also used in some supplements. Vitamin D2 and D3 are equally effective when they are converted by the liver and the kidney into the active form, 1,25-dihydroxyvitamin D.
*Process times are an estimate and are not guaranteed. The lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.