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Vitamin C (Ascorbic Acid) in Serum

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

This test measures the level of vitamin C, an essential antioxidant found in your blood serum.

Quick summary

["Vitamin C helps protect cells and supports immune function."]

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

Key facts at a glance

LOINC
41201-5
Short code
VGCC IgG Ser-sCnc
Synonyms
VGCC IgG Ser-sCnc
Category
electrolyte
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 Might You Need This Test?

Your healthcare provider may order this test to check for vitamin C deficiency, monitor vitamin C levels in certain conditions (like chronic illnesses), or evaluate how your body absorbs and uses vitamin C. It can also be part of a broader nutritional assessment or screening for conditions affecting vitamin metabolism.

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 test involves fasting-related measurements. Wear comfortable clothing and plan to rest after the blood draw.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm to collect a blood sample. You may feel a brief pinch, but the process is quick. The blood is then sent to a lab for analysis.

What Are the Possible Results?

Results are typically reported as a concentration of vitamin C in the blood. While reference ranges can vary by lab, low levels may indicate deficiency, while very high levels could suggest certain medical conditions or dietary excess.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Vitamin C

Frequently asked questions

How often should I get this test?
The frequency depends on your health status, medical history, and why the test was ordered. Your doctor will determine the best timing based on your individual needs, such as whether you have a known deficiency or are under treatment for a condition affecting vitamin C levels.
What does a low vitamin C level mean?
A low vitamin C level may mean you aren’t getting enough vitamin C through your diet or your body isn’t absorbing it properly. It can also indicate certain health conditions or medications that affect vitamin metabolism. Your doctor may recommend dietary changes, supplements, or further testing.
Can I take vitamin C supplements before the test?
It’s best to avoid taking vitamin C supplements for 24 hours before the test unless instructed otherwise by your doctor. Some supplements can affect the accuracy of the results, so follow your provider’s guidance.
  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