VITAMIN A - (S)
Test Code: VITA
This test is useful for diagnosing vitamin A (Retinol) deficiency & toxicity as well as monitoring vitamin A therapy. Vitamin A plays an essential role in the function of the retina, is essential for growth and differentiation of epithelial tissue, and is required for growth of bone, reproduction and embryonic development. It also enhances immune function reducing the consequences of some infectious diseases. Vitamin A values above 4.2 umol/L suggest hypervitaminosis A and associated toxicity. Values less than 0.4 umol/L indicate severe deficiency.
Patient Preparation Instructions:
Overnight fast (12 - 14 hours) prior to specimen collection. Testing of non-fasting specimens or the use of vitamin supplementation can result in elevated plasma vitamin concentrations.
Infants: Draw specimen prior to next feeding.
Protect from light. Gel-separator tubes are not acceptable.
Serum: 1.0 mL
Pediatric Serum: 0.5 mL
Fasting specimen recommended. Collect following an overnight fast (12-14 hours) (infants - draw prior to next feeding). Protect specimen from light. Store frozen.
Serum: 1.0 mL
Collect after an overnight fast (12 - 14 hours). Protect specimen from light. Store and ship frozen.
Turnaround time: Within 18 days
Avoid hemolysis. Protect from light - wrap with foil. Specimen must be labeled inside and outside of light-protecting wrap. Store and send frozen to In-Common Laboratories.