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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: Patient should fast overnight (12-14 hours); infants should have specimen collected before next feeding.

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

Collection Instructions: Centrifuge and aliquot serum into light protected plastic vial within 2 hours of collection.


Secondary ID

605124

Useful For

Diagnosing vitamin A deficiency and toxicity as a part of a profile

 

Monitoring vitamin A therapy

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

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 enhances immune function, reducing the consequences of some infectious diseases.

 

Degenerative changes in eyes and skin are commonly observed in vitamin A deficiency. Poor adaptation of vision to darkness (night blindness) is an early symptom that may be followed by degenerative changes in the retina. In developing countries, vitamin A deficiency is the principal preventable cause of blindness. Severe or prolonged deficiency leads to dry eye (xerophthalmia) that can result in corneal ulcers, scarring, and blindness. Another important consequence of inadequate intake is acquired immunodeficiency disease, where an increased incidence of death is associated with deficient vitamin A levels. Increased susceptibility is associated with vitamin A deficiency. In patients with HIV, vitamin A deficiency is associated with increased disease progression and mortality.

 

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.

 

Vitamin A values above 120.0 mcg/dL suggest hypervitaminosis A and associated toxicity.

Cautions

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

 

Acute ethanol ingestion may result in increased serum vitamin A levels.

Clinical Reference

1. Ball GFM. Vitamins: Their role in the human body. Blackwell Publishing; 2004:133-187

2. Ross AC. Vitamin A and carotenoids. In: Shils ME, Shike M, Ross AC, et al, eds. Modern Nutrition in Health and Disease. 10th ed. Lippincott Williams and Wilkins; 2006:351-375

3. Roberts NB, Taylor A, Sodi R. Vitamins and trace elements. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 37

4. Sodi R. Vitamins and trace elements. In: Rifai N, Chiu RWK, Young I, Burnham C-AD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:417-417.e104

Method Description

Deuterated vitamin A (d6-all-trans retinol) is added to serum as an internal standard. Vitamin A (all-trans retinol) and the deuterated internal standard are extracted from the specimens using on-line turbulent flow high-performance liquid chromatography and analyzed by liquid chromatography tandem mass spectrometry using multiple reaction monitoring in positive mode.(Unpublished Mayo method)

Day(s) Performed

Sunday through Friday

Report Available

2 to 5 days

Specimen Retention Time

14 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