Ascorbic Acid Level Test

What this test measures

Vitamin C, or ascorbic acid, is needed for the synthesis of collagen, the protein that gives structure to skin, blood vessels, tendons, and bone. It also helps the immune system function normally and protects cells from oxidative damage. Because humans cannot make vitamin C, it must come from food.

The test measures ascorbic acid in plasma or serum. Levels reflect recent intake, so the timing of the sample relative to meals and supplements can matter. Some laboratories also offer a leukocyte vitamin C measurement, which reflects body stores over a longer period.

Deficiency is uncommon in people who eat fruits and vegetables regularly, but it can occur with severely restricted diets, heavy alcohol use, malabsorption, or increased needs. Early signs may include fatigue and easy bruising, while more advanced deficiency can affect gums, joints, and wound healing.

• Plasma ascorbic acid (vitamin C)
• Serum vitamin C
• Leukocyte vitamin C
• Iron absorption related markers when paired
• Complete blood count when included
• Reference range comparison for ascorbic acid

Why people order this test

• Evaluate suspected vitamin C deficiency
• Investigate bleeding gums or easy bruising with poor diet
• Assess nutrient status in severely restricted eating
• Review vitamin C in malabsorption conditions
• Check status with increased nutritional needs
• Follow up on slow wound healing with a provider

How to prepare

Fasting may be requested because recent food or supplements can raise the result. A blood sample is drawn from a vein, usually at the arm. Follow the timing instructions provided with the order, and tell the ordering provider about supplements.

Understanding your results

Results are generally reported within one to three business days. The report shows the vitamin C level relative to the reference range. A low value suggests deficiency, and a healthcare provider interprets it with diet and symptoms.