Vitamin A
Label Mnemonic: VTA
Epic Lab Code: LAB4249
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Serum
Specimen Instructions:
Patient should fast for 12 hours and abstain from alcohol for 24 hours prior to collection.
Collection Medium:
Red top tube 5 mL (Clot Activator)
Minimum:
Preferred Minimum: 1 mL serum
Absolute Minimum: 0.2 mL serum
Rejection Criteria:
Whole blood or body fluids other than serum.
Delivery Instructions:
Deliver to laboratory immediately after collection.
Turn Around Time:
1-4 days upon receipt at reference laboratory
Reference Range:
Vitamin A (Retinol) 0-1 month 0.18 - 0.50 mg/L 2 months-12 years 0.20 - 0.50 mg/L 13-17 years 0.26 - 0.70 mg/L 18+ years 0.30 - 1.2 mg/L Retinyl Palmitate 0-150 years 0 - 0.10 mg/L
Comments:
Serum retinol is typically maintained until hepatic stores are almost depleted. Values greater than 0.30 mg/L represent adequate liver stores, whereas values less than 0.10 mg/L indicate deficiency. Samples that come in contact with plastic tubing or have been exposed to excessive light may show low results.

Vitamin A toxicity occurs when retinol concentration exceeds the capacity of retinol binding protein (RBP). Individuals with compromised renal function can retain RBP and may, therefore, have moderate retinol elevations. Drugs which interfere with vitamin A analysis include probucol (Lorelco).

This assay does not measure other vitamin A metabolites such as retinaldehyde and retinoic acid.
Test Limitations:
Samples which come in contact with plastic tubing or have been exposed to excessive light may show low results.
Methodology:
Quantitative High Performance Liquid Chromatography
CPT Code:
84590