Vitamin C for COVID Pneumonia and More

[Part 2 of 2]

The second half of the Linus Pauling Institute’s annual Pauling Day event was devoted to a question-and-answer session with the day’s panel speakers: Anitra Carr, Alpha “Berry” Fowler, Jeanne Drisko and Maret Traber. Event moderator Alexander Michels, a researcher at LPI, fielded questions submitted by the large audience watching live on Zoom and YouTube. The conversation was dominated by intriguing work being done on vitamin C and COVID-19, though several other topics were discussed as well. Here is a synopsis of the Q&A.

How much vitamin C should we be taking?

Carr answered this question first and noted that, while a lot depends on one’s condition, studies have generally found that healthy people need about 200 mg per day. Carr added that obtaining this amount through supplements is fine, since the body will excrete any excess vitamin C that is not used, but that it is also possible to ingest this amount through fruits and vegetables alone. As mentioned by Traber in her presentation, a diet of 5-9 servings per day of fruits and vegetables will usually provide enough vitamin C. Carr added the caveat that this is only the case when at least two of those servings come from fruits or vegetables with high vitamin C concentrations; foods like kiwi fruit or oranges. Further, cooking foods decreases the bioavailability of vitamin C and should be considered when calculating one’s daily vitamin C intake.

While most panelists generally agreed with Carr, they did have some additional thoughts. Michels, the event moderator, noted that LPI recommends at least 400 mg per day, simply because most people do not know if they are in sub-optimal health or suffering from Metabolic Syndrome. Given that the 200 mg value is put forth for those who are already at optimum health, in LPI’s view it is best practice to err on the side of extra vitamin C, especially since there are virtually no side effects connected with taking a higher than necessary dose. Drisko echoed Michels’ comment and added that, because of the inherent difficulties in testing vitamin C blood plasma levels, developing an accurate assessment of need is often a challenge. In keeping once again with the idea that it is better to be safe than sorry, Drisko recommends that people go as high as they can tolerate when supplementing vitamin C. This method, which Drisko personally uses, means that intake might fluctuate from day to day, but may also yield better long-term results. Fowler agreed that supplementing is a good idea and added that he personally takes 500 mg twice per day of a buffered vitamin C, which helps to minimize some of the gastral symptoms that can arise when using higher levels of the vitamin.

Is there a difference between various forms of vitamin C?

Drisko and Carr both answered this question, and both made clear that there is no difference in terms of bioavailability from one form to another. Drisko did note that lipid-encapsulated vitamin C helps to reduce gastrointestinal symptoms and recommends its use. That said, she also cautioned that lipid-encapsulated vitamin C cannot be used in intravenous treatment.

Tell us more about the use of vitamin C in treating COVID-19.

This next question was directed initially to Fowler, who is currently running a COVID-19 and vitamin C study. Fowler explained that COVID pneumonia, which is caused by a virus, creates an infection of the airways that presents in a manner similar to sepsis. Previous research has also found that viral- and bacterial-derived sepsis present in basically the same way, and that both respond well to vitamin C infusions. Based on this, Fowler felt that there could be promise in using intravenous vitamin C to treat patients suffering from COVID pneumonia.

In Fowler’s earlier research, he found that vitamin C acts as an anti-inflammatory agent. It does so by reducing the explosion of DNA that may have escaped during illness, and that often serves as a hallmark characteristic of inflammation. Fowler has also found that vitamin C reduces tissue damage. This is important because, with COVID pneumonia in particular, the virus works to destroy lung tissue.

For his current study, patients need to be positive for COVID-19, have COVID pneumonia, and be on a ventilator. In addition to the usual standards of care for COVID pneumonia, test group patients are being given an intravenous infusion of vitamin C, with dosages based on the VCU protocol. Because the study is double blind, Fowler does not know who is in the test group, but he has already noticed a stark divide in patients’ prognosis following their treatment, with some recovering rapidly and others declining. These early observations are tantalizing and may be indicative of vitamin C making a positive impact on patients suffering from COVID-19.

Drisko also spoke about her experiences related to vitamin C treatment of COVID-19. Near the beginning of the pandemic, Drisko travelled with a team of experts to Wuhan, China, the site of the index case of the virus. In Wuhan, the team treated several nearly comatose patients with vitamin C at an infusion rate of 25-50 grams per hour; rates that are similar to the VCU protocol. These patients, who were believed to be near death, wound up recovering. More detailed information on these findings is scheduled for publication.

Michels then asked the other panelists about their impressions of vitamin C and COVID-19. In response, Carr spoke of misleading studies that have prompted a false belief that vitamin C is not effective in combatting the virus. In one example, patients were given 8 grams of vitamin C orally. As Carr explained in her prepared remarks, the bioavailability of oral vitamin C is limited by the carrying capacity of transport molecules that are found in the stomach, and is thus far less effective than is intravenous vitamin C. Regardless of this limiting factor, the study did find that symptoms shortened by about 1.2 days, but that finding was not statistically significant and the study was stopped prematurely. Carr is confident that if the trial had been designed to test IVC, it would have yielded better results. Instead, the study helped to perpetuate a pessimistic narrative surrounding vitamin C’s efficacy. As Michels added, “statistically underpowered studies are misleading people and are sadly a common thing with vitamin C.”

Next, Fowler reflected on his connection with a controversial study, the VICTUS trial, which reported a negative relationship between vitamin C and COVID-19. In this instance, doctors gave patients 1.5 g of IVC four times a day, a quantity much lower than that called for by the VCU protocol. In addition to the vitamin C, patients were given 2,000 mg per day of thiamin and 50 mg of hydrocortisone four times a day. The study did not find any significant reduction in symptoms, nor a reduction in mortality. While an author on the study, Fowler emphasized that he did not participate in its design but merely helped to administer its procedures, and he pointed out several areas for criticism. In addition to the relatively low levels of vitamin C administered, the study was privately funded, and instead of the 2,000 people the study called for, just 500 people were enrolled. While critics have cited the low number of enrollees as a primary reason for such poor results, Fowler believes it was really the low levels of vitamin C. For Fowler, 50 g really is the target range for IVC, which is what is in the VCU protocol. Michels, who agreed with Fowler, commented that with vitamin C a big lesson is that “dose matters.”

Drisko then weighed in on the issue of mis-dosing. As a long-time vitamin C researcher, Drisko is confident that there is very little risk in giving a person too much vitamin C, adding that she is soon to publish a pharmacokinetic study concluding that, when cancer patients are given vitamin C up to their tolerated dose, there is no sign of organ damage. Her study also helps to combat a pervasive myth that high doses of vitamin C lead to increased bleeding or kidney damage. While the study did find increases in patients’ calcium levels, nothing about it was alarming. (Even though vitamin C has a high osmolality, the high levels of vitamin C did not destabilize calcium levels.)

Talk about the link between vitamin C and kidney stones.

In rare instances, when people are put on IVC they can develop oxalate kidney stones. To minimize these risks, Drisko recommends that all IVC patients get their urine tested to check for signs of oxalate production, an indicator of the development of these kinds of kidney stones. But, as Drisko explained, not all kidney stones are oxalate, so having a history of kidney stones is not necessarily a contraindication for IVC. More important is the need for any practitioner delivering IVC to check their patient for an inherited G6PD enzyme deficiency, because if a person has this condition and is given IVC they can develop hemolysis and risk possible death.

Drisko and Carr also commented on the risk for kidney stones posed by oral vitamin C dosing. Both agreed that this is not something that people without a history of kidney stones need to worry about, since supplementary vitamin C doses are generally equivalent to those found in a typical diet. Carr added that many studies that have shown a connection between the development of kidney stones and vitamin C do not prove cause and effect, but rather suggest a connection. There are many factors that can lead to kidney stones, such as dehydration and diet. For Carr, the popular belief that vitamin C causes kidney stones arises from weakly supported studies that do not actually prove a connection.


Alexander Michels ended the Q&A by asking panelists to comment on the future of vitamin C research, including the funding landscape for work of this sort. Carr replied that in her experience over the past two decades, finding money for vitamin C research has not gotten much easier, but that might be changing with a greater volume of encouraging results being published. Notably, researchers have recently found that vitamin C plays a role in epigenetic mechanisms and gene regulation. These data can, in turn, help support mechanistic rationales for funding, something that has often been missing in the vitamin C field. All of that said, Carr believes that the biggest barrier to stable funding is a shared body of knowledge. Too many physicians in particular are still unaware of the importance of vitamin C, and one of her jobs as a researcher is to educate colleagues about its importance. Traber agreed and noted that it is often hard to convince practitioners to trust the evidence that vitamins are important, though as more research is published, she too is hopeful that attitudes will shift.