Vitamin C Test
A vitamin C test measures the amount of ascorbic acid in your blood. Vitamin C supports collagen, wound healing, and antioxidant activity, and clinicians use this marker to help evaluate vitamin C status.
About this test
Vitamin C, or ascorbic acid, is a water-soluble vitamin with a hand in many everyday processes. It helps the body build collagen, the protein that gives structure to skin, blood vessels, gums, and connective tissue; it works as an antioxidant; it supports the immune system; and it helps the body take up iron from plant foods.
The test is done with a simple blood draw at a patient service center. A phlebotomist collects a sample from a vein in the arm, and it is sent to the laboratory.
Who might consider this test?
- A clinician may also want a look when several of these signs appear together.
Test details
| Quest code | 929 |
|---|---|
| Methodology | Chromatography/Mass Spectrometry |
| Sample type | 1 mL frozen serum - protected from light |
| Patient preparation | Fast overnight before your blood draw. Avoid eating fruits for 24 hours before collection. Avoid vitamin C supplements for 24 hours before collection. |
| Collection | Quest patient service center |
Related tests and panels
A comprehensive test designed to assess cellular defense and recovery from…
Quest resources
Additional details
What this test looks at
A vitamin C test reports how much ascorbic acid is present in a blood sample. Because vitamin C is central to building collagen, a long-running shortfall can show up in tissues that rely on that scaffolding — skin, gums, and small blood vessels among them. Measuring the circulating amount gives a clinician a reference point for whether vitamin C belongs in the conversation.
The circulating amount tends to track recent intake fairly closely, so a single measurement reflects a relatively narrow window rather than long-term stores. A clinician keeps that in mind when interpreting the result.
How clinicians use vitamin C in context
Vitamin C is usually interpreted against a person's diet, habits such as smoking, digestive health, and the symptoms that prompted the test. Rather than standing alone, the result adds one thread to a larger picture that a clinician assembles from history and, when useful, other lab work.
The measurement is meant to start a conversation with a clinician, not to close one. From there, a clinician decides in context whether anything further is worth considering.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does a vitamin C test measure?
It measures the amount of ascorbic acid in the blood. Vitamin C supports collagen formation, wound healing, antioxidant activity, and the uptake of iron from plant foods, and the measurement reflects vitamin C status.
Who commonly orders a vitamin C test?
People exploring symptoms such as easy bruising, tender gums, or slow wound healing often discuss it with a clinician, as do those with limited fruit and vegetable intake, digestive conditions affecting absorption, or a smoking habit.
How is the sample collected?
Through a routine blood draw at a patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory for analysis.
Does recent eating affect the result?
It can. The circulating amount of vitamin C tends to respond fairly quickly to recent intake, so people should follow any preparation instructions their clinician provides so the sample reflects a meaningful window.
Why is vitamin C important to the body?
Vitamin C helps build collagen, the protein that supports skin, gums, and blood vessels, and it also works as an antioxidant, supports the immune system, and aids iron uptake from plant foods.
How much does the Vitamin C test cost?
The cash price at Celio Health is $119. That covers the physician's order and sample collection at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.
Do I need to prepare for this test?
Fast overnight before your blood draw. Avoid eating fruits for 24 hours before collection. Avoid vitamin C supplements for 24 hours before collection. This is the preparation Quest publishes for this test; if your clinician gives you different instructions, follow theirs.