Serum Vitamin C (Ascorbic Acid) Concentration

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 medical conditions, or assess how your body absorbs and uses vitamin C. It can also be part of a broader evaluation for nutritional deficiencies or chronic illnesses.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for a few hours before the test if it’s part of a metabolic or liver function panel, but this isn’t always required for vitamin C alone. Bring any medications you’re currently taking to your appointment.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What Are the Results Mean?

Results are typically reported as a concentration of vitamin C in milligrams per deciliter (mg/dL). While reference ranges can vary by lab, low levels may indicate deficiency, while very high levels could suggest certain medical conditions or excessive intake.