Cardio IQ® Vitamin D, 25-Hydroxy - 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 abosrption 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.
0.5 mL serum
Collect blood in a standard red-top serum Vacutainer® tube. Allow blood to clot at room temperature. Centrifuge and separate the serum from the cells immediately.
Alternatively, collect blood in a Serum Separator Tube (SST®), allow to clot at room temperature. Centrifuge and remove from the gel within 48 hours.
Refrigerated (cold packs)
Room temperature: 21 days
Refrigerated: 21 days
Frozen: 21 days
Gross hemolysis • Grossly lipemic • Heparinized or EDTA plasma • Serum not separated from Serum Separator Tube (SST®) gel or clot within 48 hours • Grossly icteri
Vitamin D, 25-OH, Total; Vitamin D, 25-OH, D3; Vitamin D, 25-OH, D2
Fasting preferred, but not required
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Vitamin D, 25-OH, Total 30-100 ng/mL25-OHD3 indicates both endogenous production and supplementation. 25-OHD2 is an indicator of exogenous sources, such as diet or supplementation. Therapy is based on measurement of Total 25-OHD, with levels <20 ng/mL indicative of Vitamin D deficiency, while levels between 20 ng/mL and 30 ng/mL suggest insufficiency. Optimal levels are ≥30 ng/mL.
Vitamin D, 25-OH, D3 Not established
Vitamin D, 25-OH, D2 Not established
Vitamin D, 25-Hydroxy, LC/MS/MS, Cardio IQ®,CardioIQ®