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Vitamin C (Ascorbic Acid) Mass Concentration in Serum

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 supports immune function, skin health, and antioxidant protection.

Quick summary

["Check your vitamin C levels to assess dietary intake, absorption, or potential deficiencies."]

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

Key facts at a glance

LOINC
59398-8
Short code
Vit C Smn-mCnc
Synonyms
Vit C Smn-mCnc
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 poor wound healing. It could also be part of a broader evaluation for conditions like scurvy or 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 blood draw, but this is not always required for vitamin C levels. Avoid taking vitamin C supplements for 24 hours before testing if possible.

What the Test Results Mean

Results help determine if your body has enough vitamin C. Low levels may indicate poor absorption, dietary insufficiency, or certain medical conditions. High levels might suggest excessive intake or certain medications.

Common Reasons for Testing

This test is often used to diagnose vitamin C deficiency, monitor long-term vitamin C intake, or evaluate conditions like scurvy, malabsorption syndromes, or chronic illnesses that may affect nutrient absorption.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Vitamin C

Frequently asked questions

What does a low vitamin C level indicate?
A low vitamin C level may indicate a deficiency, which can weaken your immune system, slow wound healing, and increase susceptibility to infections. Chronic deficiencies can also lead to more severe conditions like scurvy.
How might high vitamin C levels affect me?
High vitamin C levels in some individuals may cause gastrointestinal discomfort, such as nausea or diarrhea, especially if taken in very high doses. Rarely, very high levels can lead to kidney stones or other metabolic issues.
Can vitamin C levels change with diet or supplements?
Yes, vitamin C levels can fluctuate based on diet, vitamin C supplements, smoking, and certain medications. Smoking, for example, can deplete vitamin C stores, so quitting may help restore levels over time.
  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