Vitamin C (Ascorbic Acid) in Serum or Plasma
This test measures the amount of vitamin C, a water-soluble antioxidant, in your blood. Vitamin C helps protect cells from damage and supports immune function.
["Check your vitamin C levels to ensure your body has enough for good health and immune support."]
Key facts at a glance
- LOINC
- 30073-1
- Short code
- VGCC Ab Ser Ql
- Synonyms
- VGCC Ab Ser Ql
- Category
- electrolyte
- 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 doctor may order a vitamin C test to evaluate your nutritional status, diagnose deficiencies (such as scurvy), or monitor conditions like chronic kidney disease, where vitamin C levels can be affected. It may also be used in research or specialized clinical settings to assess antioxidant status.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the blood draw if your test involves serum or plasma. Avoid taking vitamin C supplements for 24 hours before testing to get an accurate result.
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. The test typically takes a few minutes, and you may feel a slight pinch during the draw.
What Are Possible Results?
Results are reported in milligrams per deciliter (mg/dL) or micrograms per milliliter (µg/mL). While reference ranges vary by lab, low levels may indicate deficiency, while very high levels could suggest overconsumption or certain medical conditions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low vitamin C levels can weaken immunity, cause fatigue, or lead to skin problems. Chronic deficiencies may affect wound healing or increase infection risk. High levels might be linked to kidney stones or other metabolic issues, depending on context. Always discuss results with your doctor.
Short name
Vitamin C Level
Frequently asked questions
What causes vitamin C deficiency?
How long does it take to recover from a vitamin C deficiency?
Can vitamin C supplements replace a blood 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