Vitamin C, also known as ascorbic acid, is currently making headlines in the fight against COVID-19. Reports say that intravenous (IV) vitamin C may help people suffering from this disease.

Recently, IV vitamin C clinical trials began in China and Italy. Doctors in hard-hit areas of the United States are now reporting using it. Furthermore, IV vitamin C appears in some COVID-19 critical care guidelines, like at the Eastern Virginia Medical School.

Even though using IV vitamin C is nothing new, there is not enough scientific evidence to determine if it works against COVID-19.  Read on for more information.

What is IV vitamin C?

A solution of vitamin C is delivered directly into the bloodstream through a vein, typically in the arm. A physician’s order is required to receive this treatment. It is important to get IV vitamin C only in a clinic or other medical setting.


Why use IV vitamin C?

IV vitamin C goes straight into the bloodstream. Because it skips the stomach and intestines, vitamin C in the blood rises to very high levels and very quickly.

What do we know about IV vitamin C in COVID-19?

The clinical data from IV vitamin C trials will not be available for many months. So far, doctors and researchers cannot tell how effective IV vitamin C is or how it might work.

There is some scientific evidence that IV vitamin C can be useful in the treatment of other infections. Most of the recorded use of IV vitamin C has been in the treatment of cancer.

To be clear: IV vitamin C is not a cure for COVID-19

What about vitamin C supplements?

It is hard to compare them. You cannot get blood vitamin C levels nearly as high as IV vitamin C when taking vitamin C supplements

Despite label claims, no supplement is equal to IV vitamin C – no matter how much you take or what formula you use.

Can vitamin C supplements help your immune system? Yes, but for different reasons.

Caution: Be careful taking very high doses of vitamin C supplements. They can also cause unwanted side effects such as abdominal cramping and diarrhea.

How might IV vitamin C work in COVID-19 patients?

There are several theories about how IV vitamin C may help treat COVID-19:

  • Very high vitamin C levels may create free radicals that destroy viruses and bacteria. Our body’s cells have defenses against these free radicals, but viruses do not.
  • Another possibility is IV vitamin C renews the body’s antioxidant protection. Serious infections can use up our body’s vitamin C and other antioxidants very quickly.

Vitamin C is a vital part of the immune system, but there is no reason to think IV vitamin C can boost your immune system beyond normal, healthy status. Daily vitamin C from food or supplements is enough to support healthy immunity.

Is IV vitamin C safe?

IV infusions always require proper administration by a medical professional. Patients need to be screened to make sure it is safe for them. Some conditions might prevent a person from getting IV vitamin C.

From research on vitamin C and cancer, we know that IV vitamin C is safe when medical guidelines are followed.

  • Although doctors are using IV vitamin C, there is no published scientific evidence about the use of IV vitamin C in COVID-19. Therefore, we cannot fully evaluate its effectiveness.

  • IV vitamin C is not the same as taking vitamin C supplements. Vitamin C supplements may help the immune system, but vitamin C blood levels that are far lower than IV vitamin C.

  • The National Cancer Institute provides more information about IV vitamin C that may be helpful if you want to know more about this therapy.

  • For more information about vitamin C in the immune system, see the Micronutrient Information Center

Authors: Alexander Michels, PhD; Victoria Drake, PhD; Sandra Uesugi, RN, BSN, MS, all from the Linus Pauling Institute at Oregon State University. Contact information here.