While measurements of 25(OH)D provide a good index of circulating Vitamin D activity in patients not suffering from renal disease, for infants less than 2 years of age it is important to remove circulating levels of the inactive c3-epimer of Vitamin D from the sample so that total Vitamin D levels are not falsely elevated. Falsely elevated results could erroneously make the child appear to be within normal limits and result in potential under-treatment. Levels of c-3 epimer in older children and adults are usually negligible and do not cause falsely elevated Vitamin D results. This assay employs advanced liquid chromatography-tandem mass spectrometry, which enables the chromatographic separation of the c3-epimer from 25-OH Vitamin D thereby allowing accurate measurement in the presence of c3-epimer. While this assay will produce accurate Vitamin D results on patients of any age, it is specifically indicated for infants less than 3 years of age.
Fasting samples are preferred but not required. 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 at room temperature, centrifuge and remove from the gel
within 48 hours.
Reported (Analytical Time)
The CPT codes provided are based on AMA guidelines and are for informational purposes only.
CPT coding is the sole responsibility of the billing party.
Please direct any questions regarding coding to the payer being billed.
Methodology: Chromatography/Mass Spectrometry Transportation temperature: Room temperature Reject Criteria: Gross hemolysis; grossly lipemic; plasma; serum not separated from serum separator tube; serum not separated from gel or clot within 48 hours; grossly icteric