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Vitamin C (Ascorbic Acid) in Serum by Enzymatic Method

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

This test measures the amount of vitamin C (ascorbic acid) in your blood serum. Vitamin C is an essential nutrient that helps support your immune system, skin health, and wound healing.

Quick summary

["Vitamin C levels help assess your body’s vitamin C stores and overall health status."]

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

Key facts at a glance

LOINC
35153-6
Short code
Deprecated VLCFA C26:1 SerPl-sCnc
Synonyms
Deprecated VLCFA C26:1 SerPl-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 to check for vitamin C deficiency, monitor vitamin C levels after supplementation, or evaluate conditions linked to low vitamin C, such as scurvy or certain nutritional deficiencies.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for a few hours before the test, but this depends on your healthcare provider’s instructions. Bring any supplements or medications you’re taking to your appointment.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The blood sample is sent to a lab for analysis using an enzymatic method to measure vitamin C levels accurately.

What Are the Results Mean?

Results are typically reported as a mass concentration of vitamin C in the serum. Low levels may indicate deficiency, while higher levels could suggest recent supplementation or certain medical conditions. Your results will be interpreted by your healthcare provider in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Vitamin C

Frequently asked questions

What causes vitamin C levels to be low?
Vitamin C deficiency can result from poor diet (low intake of fruits and vegetables), certain medical conditions (e.g., malabsorption disorders), or excessive alcohol use. Rarely, genetic disorders or medications may also affect levels.
How long does it take to get results?
Test results are usually available within 1–3 business days, depending on your lab’s processing time. Your healthcare provider will contact you once the results are ready.
Can I take vitamin C supplements before the test?
Yes, but follow your healthcare provider’s advice. If they recommend fasting, avoid supplements for a specified period to ensure accurate results. If no fasting is required, supplements may not interfere, but discuss this with your provider.
  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