Vitamin C (Ascorbic Acid) in Serum or Plasma
This test measures the amount of vitamin C, an essential nutrient that helps protect cells from damage and supports immune function.
["Vitamin C helps your body fight infections and maintain healthy skin and tissues."]
Key facts at a glance
- LOINC
- 54350-4
- Short code
- Vit C+DHA SerPl-sCnc
- Synonyms
- Vit C+DHA 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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms of vitamin C deficiency, such as fatigue, frequent infections, or slow wound healing. It could also be used to monitor vitamin C levels in people taking supplements or those with certain medical conditions that affect nutrient absorption.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for a few hours before the blood draw, but this depends on your provider’s instructions. Bring any supplements or medications you’re taking to discuss with your doctor.
How the Test Works
A small sample of blood is drawn from a vein in your arm. The sample is then sent to a lab to measure vitamin C levels using a specialized immunoassay method, which detects the presence of vitamin C in your serum or plasma.
What the Results Mean
Results may indicate whether your vitamin C levels are within a normal range, lower than expected (deficiency), or higher than expected (elevated). Your doctor will interpret the results in the context of your overall health and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low vitamin C levels can weaken your immune system, increase the risk of infections, and slow healing. High levels may not always cause symptoms but can sometimes indicate over-supplementation or certain medical conditions. Regular monitoring is important for people with chronic illnesses or those on long-term vitamin C therapy.
Short name
Vitamin C Level
Frequently asked questions
How long does it take to get my results?
Can I take vitamin C supplements before the test?
What are the common symptoms of vitamin C deficiency?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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