Vit A
A vitamin essential to vision, immune function, and skin.
What is it
Vitamin A (retinol) is essential to vision, immune function, and epithelial cell health. Both deficiency and excess have health implications.
Why it's measured
Vitamin A status has been studied in research on vision, immune function, and bone health.
Reference range
Standard laboratory reference
30 – 80 μg/dL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with toxicity at high values in research literature, typically from supplementation.
Lower
Has been associated with night vision changes and immune dysfunction in research literature.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Measured in comprehensive nutrient panels and certain clinical scenarios.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.