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Test Code VITAP Vitamin A, Serum


Specimen Required


Only orderable as part of a profile. For more information see VITAE / Vitamin A and Vitamin E, Serum.

 

Patient Preparation:

1. Fasting: 12 hours, required; Infants should have specimen collected before next feeding

2. Patient must not consume any alcohol for 24 hours before specimen collection.

Supplies: Amber Frosted Tube, 5 mL (T915)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Amber vial

Specimen Volume: 0.5 mL serum

Collection Instructions: Within 2 hours of collection, centrifuge and aliquot serum into light protected plastic vial.


Useful For

Diagnosing vitamin A deficiency or toxicity as part of a profile

 

Monitoring vitamin A therapy as part of a profile

Method Name

Only orderable as part of a profile. For more information see VITAE / Vitamin A and Vitamin E, Serum.

 

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Vitamin A, S

Specimen Type

Serum

Specimen Minimum Volume

Serum: 0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days LIGHT PROTECTED
  Frozen  28 days LIGHT PROTECTED
  Ambient  7 days LIGHT PROTECTED

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Clinical Information

The level of vitamin A in the plasma or serum is a reflection of the quantities of vitamin A and carotene (provitamin A) ingested and absorbed by the intestine (carotene is converted to vitamin A by intestinal absorptive cells and hepatocytes).

 

Vitamin A plays an essential role in the function of the retina (adaptation to dim light), is necessary for growth and differentiation of epithelial tissue, and is required for growth of bone, reproduction, and embryonic development. Together with certain carotenoids, vitamin A also plays a critical role in immune function, with deficiency associated with increased susceptibility and severity of some infectious diseases.

 

Degenerative changes in eyes and skin are commonly observed in vitamin A deficiency. In developing countries, vitamin A deficiency is the principal preventable cause of blindness. Poor adaptation of vision to darkness (nyctalopia, night blindness) is an early symptom that may be followed by degenerative changes in the retina. Severe or prolonged deficiency leads to xerophthalmia, which can result in dry eye, corneal ulcers, Bitot spots, keratomalacia, and ultimately blindness. Skin changes such as dry skin, generalized xerosis, and phrynoderma are commonly observed in conjunction with vision disorders caused by vitamin A deficiency.

 

Vitamin A in excess can be toxic. In particular, chronic vitamin A intoxication is a concern in normal adults who ingest more than 15 mg per day and children who ingest more than 6 mg per day of vitamin A over a period of several months. Manifestations are various and include dry skin, cheilosis, glossitis, vomiting, alopecia, bone demineralization and pain, hypercalcemia, lymph node enlargement, hyperlipidemia, amenorrhea, and features of pseudotumor cerebri with increased intracranial pressure and papilledema. Liver fibrosis with portal hypertension may also result. Congenital malformations, like spontaneous abortions, craniofacial abnormalities, and valvular heart disease have been described in pregnant women taking vitamin A in excess. Consequently, in pregnancy, the daily dose of vitamin A should not exceed 3 mg.

Reference Values

Only orderable as part of a profile. For more information see VITAE / Vitamin A and Vitamin E, Serum.

 

0-6 years: 11.3-64.7 mcg/dL

7-12 years: 12.8-81.2 mcg/dL

13-17 years: 14.4-97.7 mcg/dL

≥18 years: 32.5-78.0 mcg/dL

Interpretation

The World Health Organization recommends supplementation when vitamin A levels fall below 20.0 mcg/dL. Severe deficiency is indicated at levels less than 10.0 mcg/dL. There is no widely accepted serum vitamin A level associated with toxicity.

 

The rare occurrence of low Vitamin A and E levels might correlate with potential deficiency and investigation of potential fat malabsorptions should be considered.

Cautions

Acute alcohol ingestion may result in increased serum vitamin A levels. Patients should abstain from alcohol for 24 hours prior to collection.

 

Testing of nonfasting specimens or the use of vitamin supplementation can result in elevated serum vitamin concentrations. Reference values were established using specimens from individuals who were fasting.

Day(s) Performed

Monday through Friday, Sunday

Report Available

2 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

84590

LOINC Code Information

Test ID Test Order Name Order LOINC Value
VITAP Vitamin A, S 2923-1

 

Result ID Test Result Name Result LOINC Value
605124 Vitamin A 2923-1