Vitamin D, 25-Hydroxy (D2+D3 Fractionated), LC/MS-MS
Collect SST, red top, lavender EDTA or green top heparin. Within 45 minutes of collection, centrifuge and transfer 1 mL serum/plasma to a screw top plastic vial, indicate sample type on tube and send.
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Room temp: 7 days, Refrigerated: 7 days, Frozen: 34 days
25-Hydroxy vitamin D is used to measure vitamin D status; it includes results for total 25-hydroxy vitamin D2 and 25-hydroxy vitamin D3.