Is Vitamin C an Antioxidant?

Dec 15, 2022 11:16:34 AM

Written By:
Dr. Ian Bier


Vitamin C is widely known for supporting immune health. Did you know it’s also an antioxidant? This article explains what antioxidants are, how they function in the body, and the unique and lesser-known benefits of vitamin C.

antioxidants vs. free radicals

While it sounds odd, your body is rusting with each passing day. That’s right—ordinary bodily functions like eating and breathing are constantly creating byproducts called free radicals. These highly volatile molecules degrade materials wherever they can, from the delicate tissue in your eyes to the metal furniture on your patio. Vitamin C is one compound that can help protect from excessive rusting, AKA, free radical damage..

Antioxidants, like vitamin C, are substances that work to protect you from the rampant destruction of free radicals circulating in the body. To combat a surplus of free radicals and their resulting damage, we can increase our intake of vitamin C and other antioxidants by making well informed choices about the foods and supplements we consume.

We asked three reputable physicians for the fundmental steps to a stronger  immune system. Get their answers in our guide. 

what are antioxidants, exactly?

A popular buzzword you’ve likely seen on the labels of plenty of foods, supplements, and beverages, antioxidants are molecules that help to neutralize the negative health effects of the free radicals in the body.[1]

Free radicals are oxygen-based molecules with an imbalanced amount of electrons. An antioxidant is a molecule that has an extra electron available to donate to the free radical molecule. The antioxidant’s electron donation stabilizes the free radical’s otherwise insatiable need to bind with—and thereby damage—your healthy tissue.

While the body does create some of its own antioxidants, designed to combat the amount of oxidative stress an average prehistoric human would experience, they aren’t enough. In today’s world of high stress, water and air pollution, cigarettes, alcohol, polyunsaturated fatty acids, radiation, and even extreme exercise[2], our in-house production of antioxidants, such as glutathione, simply can’t keep up.

vitamin c: an excellent antioxidant 

Although most animals can produce their own vitamin C, humans, gorillas, and guinea pigs, among others, have genetically lost this ability over time. Thus, vitamin C is considered an “essential” nutrient, in that we must source it from our food or supplements.

Vitamin C, also known as ascorbic acid, was discovered in the 1920s and thought of as the key to preventing scurvy. Researchers noted that when humans did not have access to fruit or vegetables for long periods of time, they often developed scurvy, a deadly disease marked by bleeding gums and easily bruising skin. British rations quickly began to include citrus fruits to combat the issue, earning their sailors the “limey” nickname.

The benefits of vitamin C are now recognized to be far more expansive. This essential nutrient supports many structural and functional systems, helping to:

  • Boost immune function*
  • Prevent neurodegenerative problems*[3]
  • Maintain blood pressure at a normal range*
  • Optimize iron levels*
  • Improve stress response*
  • Support connective tissue repair and collagen cross synthesis*

Prolonged exposure to too many free radicals and not enough antioxidants leads to a variety of health problems. Luckily, vitamin C and other antioxidants are readily available in our food supply and dietary supplements.

best sources of vitamin c

If you think of an orange as the quintessential vitamin C source, you’re not wrong. Citrus fruits are an excellent and versatile source of vitamin C. Just one orange per day contains 75mg, providing 75% of the average Recommended Daily Allowance (RDA) of 100mg.

But oranges aren’t the only source of vitamin C. One cup of steamed broccoli provides more vitamin C than an orange, and bell peppers, tomatoes, and strawberries are also rich sources of this powerful antioxidant. Additionally, consuming vitamin C-rich foods alongside a leafy green salad improves your body’s ability to absorb iron from the meal. Eat these foods raw or lightly cooked, as vitamin C is a delicate, water-soluble vitamin that degrades easily when heated or processed.

supplementing with vitamin c

In addition to sourcing vitamin C from your food, you can find it in dietary supplements to use daily. Look for high-quality, bioavailable vitamin C, either in a time-release formulation to provide smaller doses throughout the day, a convenient powder, or a liposomal vitamin C for enhanced digestibility.*

When supplementing with vitamin C, moderation is key. Because the body does not keep stores of vitamin C, you must continue to source the recommended amounts daily. As a water-soluble vitamin, excess vitamin C is excreted regularly, and supplementing in high doses can lead to uncomfortable outcomes such as diarrhea. Continued mega dosing can potentially lead to problems such as kidney stones.

related content: the difference between liposomal c and vitamin c?


Vitamin C is a well-known and readily available antioxidant that helps support the body’s immune function and wards off damage from free radicals.* Instead of relying only on oranges, enjoy a variety of berries and cruciferous veggies as other excellent sources of vitamin C. Supplementing daily with high-quality, bioavailable vitamin C is generally well tolerated and effective at reducing oxidative stress in the tissues.*


Support Immune Health

[1] Dizdaroglu M, Jaruga P. Mechanisms of free radical-induced damage to DNA. Free Radic Res. 2012 Apr;46(4):382-419. doi: 10.3109/10715762.2011.653969. PMID: 22276778.

[2] Powers SK, Jackson MJ. Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production. Physiol Rev. 2008 Oct;88(4):1243-76. doi: 10.1152/physrev.00031.2007. PMID: 18923182; PMCID: PMC2909187.

[3] Kocot J, Luchowska-Kocot D, Kiełczykowska M, Musik I, Kurzepa J. Does Vitamin C Influence…Nutrients. 2017 Jun 27;9(7):659. doi: 10.3390/nu9070659. PMID: 28654017; PMCID: PMC5537779.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.