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Vitamin A (Retinol) in Serum or Plasma

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of vitamin A, an essential nutrient important for vision, immune function, and skin health, in your blood.

Quick summary

["Vitamin A levels help ensure you’re getting enough of this vital nutrient for proper body function."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
3194-8
Short code
Fact V Ag PPP IA-aCnc
Synonyms
Fact V Ag PPP IA-aCnc
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like night blindness, dry skin, frequent infections, or if you’re at risk for vitamin A deficiency—such as due to poor diet, certain medical conditions, or malabsorption issues.

What to Expect Before the Test

No special preparation is usually needed. You may fast for 8–12 hours before the test if it’s a fasting sample, but check with your provider first. Bring any medications you’re taking to discuss with your healthcare team.

What Happens During the Test?

A small blood sample is drawn from a vein in your arm. The sample is sent to a lab for analysis. The test typically takes a few minutes, and you may feel slight discomfort but no lasting effects.

What Do Results Mean?

Results are compared to a general reference range, but exact values can vary by lab. Low levels may indicate deficiency, while very high levels could signal liver disease or other conditions. Your provider will interpret results in the context of your health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Vitamin A Level

Frequently asked questions

How long does it take to get my results?
Results are usually available within 1–3 business days, depending on your lab and healthcare provider. Follow-up may be scheduled if further testing or adjustments to your care are needed.
Can I eat or drink anything before this test?
If fasting is required, avoid food and liquids (except water) for 8–12 hours before the test. Always confirm with your provider to avoid delays or incorrect results.
What are the most common causes of low vitamin A levels?
Low vitamin A levels can result from poor dietary intake, certain digestive disorders (like celiac disease), liver disease, or conditions affecting fat absorption (e.g., cystic fibrosis). Symptoms like dry eyes or night blindness may also signal deficiency.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy