Vitamin A
Category | Biochemistry | ||||||||||||
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Test background |
Retinol, the dietary form of vitamin A, is a fat-soluble, antioxidant vitamin important in vision and bone growth. Vitamin A synthesis is achieved through hydrolysis of animal-derived retinyl esters to retinol and, similarly, from pro-vitamin A plant carotenoids. Vitamin A is essential for skin growth, bone formation, immune function and vision. One of the earliest signs of vitamin A deficiency is night-blindness, followed by decreased visual acuity. Excess vitamin A can be hepatotoxic and moderately-elevated chronic levels correspond to increased incidence of osteoporotic events. |
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Clinical Indications |
Suspected deficiency or suspected toxicity/overdose |
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Reference range |
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Sample & container required | SST (gold top), serum (red top) or heparin (green top). Samples should be protected from light. | ||||||||||||
Sample volume | 0.5 mL | ||||||||||||
Turnaround time | 2 weeks | ||||||||||||
Notes | Usually only indicated in case of overdoses or chronic ingestion. Freeze samples immediately after separation and protect from light. Samples can be shipped frozen or sent by First class post. Due to a method change on 28th January 2025, we are not currently accredited for this test. An application for assessment will be submitted. |