Can Vitamin C Treat COVID-19?
By Tara Garfield, Rejuvenan Nutrition Team
As researchers around the world race to find effective treatments for the novel coronavirus, medical advice for how to cure COVID-19 has spread rapidly on social media. One claim that has gained attention recently is that high doses of vitamin C can cure coronavirus infections. Before you start searching for ways to consume more vitamin C, it is important to fully understand the science behind the claim.
How did vitamin C become the go-to supplement for treating disease?
The association between vitamin C and the ability to prevent and/or treat disease was made by Nobel prize winning chemist, Linus Pauling. He wrote a best selling book called, Vitamin C and the Common Cold, in which he suggested that vitamin C could be a cure-all for many ailments and recommended individuals consume 2,000 mg daily (the recommended dietary allowance for people 19+ is 90 mg for men, and 75 mg for women). Many studies have followed, but results have been inconsistent causing confusion and controversy, although public interest in vitamin C remains high.
The National Institutes of Health summarizes the research on vitamin C and its effectiveness in treating the common cold by stating:
“Overall, the evidence to date suggests that regular intakes of vitamin C at doses of at least 200 mg/day do not reduce the incidence of the common cold in the general population, but such intakes might be helpful in people exposed to extreme physical exercise or cold environments and those with marginal vitamin C status, such as the elderly and chronic smokers. The use of vitamin C supplements might shorten the duration of the common cold and ameliorate symptom severity in the general population, possibly due to the anti-histamine effect of high-dose vitamin C. However, taking vitamin C after the onset of cold symptoms does not appear to be beneficial.”
Based on the outcomes of previous studies, researchers and doctors are working to see if vitamin C has similar effects on those with COVID-19.
Vitamin C and COVID-19
Hospitals in New York have started to treat patients with vitamin C based on reports that it has helped individuals in China. The hope is that high doses of IV vitamin C may help prevent cytokine-induced damage to the lungs. Cytokines are small proteins released by cells, which trigger inflammation and respond to infection. Physicians have also noticed that vitamin C levels in coronavirus patients decrease dramatically when they suffer from sepsis, an inflammatory response that occurs as a complication from infection. Therefore, high doses of vitamin C are being used to try and maintain serum levels and prevent this large drop from occurring.
Vitamin C is likely safe to use both prior to, and during, COVID-19 infection. There is a low risk for toxicity when vitamin C is taken in large amounts and it is believed not to cause serious adverse effects — the most common complaints being gastrointestinal disturbances such as diarrhea and nausea.
Currently, there are at least two clinical trials testing intravenous vitamin C’s effects on coronavirus, one in Italy and one in China; however, the studies are ongoing, so no findings have yet been published. The study in China is estimated to be complete by the end of September. Therefore, the true benefit of vitamin C during COVID-19 infection continues to be unknown.
Do you need to supplement?
The information and understanding of COVID-19 continues to change rapidly and it is important to reiterate that, to date, there are no clinically evidence-based integrative prevention or treatment strategies for COVID-19 infection. Vitamin C may help shorten the duration and severity of colds caused by other viruses, but there is no guarantee that it will have the same effect on the coronavirus that causes COVID-19.
Additionally, vitamin C is a water soluble vitamin, meaning that amounts consumed in excess are excreted in the urine and not stored in the body. Therefore, taking more vitamin C does not mean that you are absorbing more vitamin C. Although high doses of vitamin C appear to be helpful for treating COVID-19, these doses are exceptionally high and given intravenously — not taken orally. Therefore, there is no evidence to support the use of oral vitamin C supplements for COVID-19. Given the many unknowns, it is advised to consume a diet rich in fruits and vegetables which naturally contain all the vitamin C a healthy person needs, in addition to many other nutrients and antioxidants. We cannot emphasize enough that the best way to protect yourself from COVID-19 is by taking preventative measures such as frequent hand washing, social distancing, and to avoid touching your eyes, nose, and mouth.
