Test Details
Methodology
High-pressure liquid chromatography (HPLC)
Result Turnaround Time
3 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Confirm the diagnosis of carotenoderma; detect fat malabsorption; depressed carotene levels may be found in cases of steatorrhea.
Limitations
High levels are useful to rule out steatorrhea but lower values lack specificity. There is poor sensitivity. High in the serum of those ingesting large amounts of vegetables. The gold standard for confirmation of a diagnosis of malabsorption remains fat measurement of a 72-hour stool specimen.
Custom Additional Information
Vitamin A serum levels do not correlate well with liver stores. Carotenemia may be confused with jaundice. It is also reported high with some cases of diabetes mellitus, myxedema, chronic nephritis, nephrotic syndrome,1,2 liver disease, hypothyroidism, type I, IIA, and IIB hyperlipoproteinemia, and in a group of amenorrheic hypogonadotropic women.1 An inverse relationship between serum β-carotene and the risk of bronchogenic squamous cell carcinoma is reported.3 The highest carotene levels are found in the serum of faddists ingesting large amounts of vegetables.4 Oral leukoplakia responds well to β-carotene therapy.5 Low β-carotene levels are associated with oral contraceptives and smoking.6
Specimen Requirements
Specimen
Serum, protected from light
Volume
0.7 mL
Minimum Volume
0.4 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube or gel-barrier tube; amber plastic transport tube with amber top. (If amber tubes are unavailable, cover standard transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient's name directly on the container and on the outside of the aluminum foil. Secure with tape.) For amber plastic transport tube and amber-top, order LabCorp N° 23598.
Collection Instructions
Specimen should be free from hemolysis. Protect from light. Transfer specimen to amber plastic transport tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
3−91 μg/dL
Storage Instructions
Room temperature and protect from light.
Patient Preparation
Patient should fast for 12 hours and abstain from alcohol for 24 hours prior to collection. For those who are younger than six months, draw prior to next feeding. Blood should be collected before breakfast in the morning and prior to any medication.
Causes for Rejection
Specimen not protected from light; hemolysis; sample type other than serum received
Footnotes
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 001529 | Carotene, Beta | 2053-7 | 001529 | Carotene, Beta | ug/dL | 2053-7 |
| Order Code | 001529 | |||||
| Order Code Name | Carotene, Beta | |||||
| Order Loinc | 2053-7 | |||||
| Result Code | 001529 | |||||
| Result Code Name | Carotene, Beta | |||||
| UofM | ug/dL | |||||
| Result LOINC | 2053-7 |