Vitamin C (Ascorbic Acid) in Serum or Plasma
This test measures the amount of vitamin C, also called ascorbic acid, in your blood. Vitamin C is an essential nutrient that helps protect cells, supports immune function, and aids in wound healing.
["Check your vitamin C levels to ensure you’re getting enough of this important nutrient."]
Key facts at a glance
- LOINC
- 6686-0
- Short code
- Deprecated Vit C SerPl-mCnc
- Synonyms
- Deprecated Vit C SerPl-mCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test if you have symptoms of vitamin C deficiency, such as fatigue, frequent infections, or slow wound healing. It may also be used to monitor vitamin C levels in people taking supplements or those with conditions that affect nutrient absorption, like celiac disease or malabsorption syndromes.
Who Might Need This Test?
People at higher risk of vitamin C deficiency may undergo this test, including those with chronic illnesses, heavy smokers, individuals with certain dietary restrictions, or those undergoing chemotherapy. It may also be part of routine screening in specific clinical settings.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw if your doctor specifies it. Avoid taking vitamin C supplements 24 hours before the test, as this could affect results.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis using a method like immunoassay or enzymatic techniques to measure vitamin C levels.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low vitamin C levels may indicate deficiency, which can weaken immunity, cause scurvy-like symptoms, or worsen chronic conditions. High levels might suggest overconsumption of supplements or certain medical conditions. Results help guide treatment plans, such as adjusting dietary intake or supplement use.
Short name
Vitamin C Level
Frequently asked questions
What does a low vitamin C level mean?
Can vitamin C supplements interfere with this test?
How often should I get this test?
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