Serum or Plasma Total Antioxidant Capacity (measured as milligrams of ascorbic acid equivalent per deciliter)

What Does This Test Measure?

Total antioxidant capacity reflects the combined activity of various antioxidants in your blood, including vitamins (like vitamin C and E), enzymes, and other molecules that scavenge free radicals. This test does not isolate specific antioxidants but provides an overall measure of your body’s antioxidant capacity.

Why Might You Need This Test?

Your doctor may order this test if you have symptoms of oxidative stress (e.g., chronic fatigue, frequent infections) or if you’re at higher risk for conditions linked to oxidative damage, such as cardiovascular disease or certain cancers. It can also be part of routine health assessments for older adults or those with metabolic disorders.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood draw from a vein in your arm, similar to other blood tests. If you’re taking blood plasma instead of serum, your sample will be collected into a special tube without a clot activator.

What the Results Mean

Lower than expected results may suggest insufficient antioxidant defenses, potentially indicating inflammation, chronic illness, or poor diet. Higher than expected results could reflect temporary stress (e.g., infection) or specific conditions like diabetes. Your doctor will interpret results in the context of your overall health.