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Lab Dept:
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Chemistry
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Test Name:
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VITAMIN A ASSAY
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General Information
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Lab Order Codes:
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VAS
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Synonyms:
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Retinol
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CPT Codes:
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84590 – Vitamin A
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Test Includes:
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Vitamin A (Retinol) level reported in mcg/dL.
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Logistics
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Test Indications:
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Useful for diagnosis of Vitamin A deficiency and elevated Vitamin A levels. Monitoring Vitamin A therapy.
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Lab Testing Sections:
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Chemistry - Sendouts
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Referred to:
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Mayo Medical Laboratories (Mayo Test# 60298)
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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2 – 5 days, testing set up Monday - Friday
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Special Instructions:
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See Patient Preparation and Collection below
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Specimen
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Specimen Type:
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Blood
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Container:
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Red top (plain, no gel) tube
Note: SST (serum separator tube) is not acceptable
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Draw Volume:
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0.5 mL (Minimum: 1 mL) blood
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Processed Volume:
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0.5 mL (Minimum: 0.25 mL) serum
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Collection:
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Routine venipuncture. Protect from light by wrapping specimen in foil.
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Special Processing:
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Lab Staff: Centrifuge specimen, remove serum aliquot into an amber light resistant vial (Mayo Supply T192). Store and ship at refrigerated temperatures. Forward promptly.
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Patient Preparation:
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Patient must be fasting 12 - 14 hours (overnight fast) before specimen is collected. Infants should be drawn prior to next feeding.
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Sample Rejection:
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Improper patient preparation may yield useless results. Exposure of the specimen to light may result in falsely decreased values. Serum separator tubes are not acceptable, warm specimens, mislabeled or unlabeled specimens.
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Interpretive
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Reference Range:
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Retinol (Vitamin A):
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Reference Value (mcg/dL)
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0 - 6 years:
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11.3 – 64.7 mcg/dL
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7 - 12 years:
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12.8 – 81.2 mcg/dL
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13 - 17 years:
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14.4 – 97.7 mcg/dL
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≥18 years:
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32.5 – 78.0 mcg/dL
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Critical Values:
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N/A
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Limitations:
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Acute ethanol ingestion may result in increased serum vitamin A levels. Testing of nonfasting specimens or the use of vitamin supplementation can result in elevated plasma vitamin concentrations. Reference values were established in patients who were fasting.
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Methodology:
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Liquid Chromatography – Tandem Mass Spectrometry (LC-MS/MS), specific quantitation of retinol
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References:
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Mayo Medical Laboratories Web Page November 2008
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Updates:
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6/5/2007: Addition of pediatric reference ranges.
11/18/2008: Mayo update.
9/28/2010: Change in Mayo order number (now only performed at Mayo New England), reference range and units update, specimen volume requirement decrease.
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