Doctors in New York have been prescribing critically ill coronavirus patients’ large doses of vitamin C, and it is also being trialled in hard-hit China where COVID-19 originated.
But the results of a study at Wuhan University – where 140 patients are being given big amounts of the antioxidant intravenously to establish if it could improve outcomes – will not be completed until September.
At the moment, there is no evidence that taking vitamin C supplements could prevent or cure the respiratory illness COVID-19, a UK health expert has told Sky News.
Posts have also been widely shared online about the supposed wonders of vitamin C, including one of a quote by the late doctor Robert F Cathcart, who said: “I have not seen any flu yet that was not cured or markedly ameliorated by massive doses of vitamin C.”
Medical health experts say there is limited evidence that vitamin C can even prevent the common cold, let alone fight off the new and unique COVID-19 that emerged in Wuhan, China, in December 2019.
Harriet Smith, an award-winning registered dietitian based in Surrey, told Sky News: “Vitamin C does play an important role in immunity. A great example of this is in sailors who developed scurvy due to vitamin C deficiencies.
“However, there’s some very limited evidence that vitamin C supplements may reduce severity and duration of common colds, but only by approximately half a day.
“Obviously, coronavirus and common colds are very different viruses, so the results don’t apply to coronavirus.”
She debunked the claim that large doses of vitamin C could make a difference, adding: “The RNI [Reference Nutrient Intake] is 40 milligrams a day, which you can easily get from eating one large orange or a kiwi fruit.
“Vitamin C is water-soluble, so consuming more than the body needs will result in it being excreted in urine.”
She continued: “I would not recommend people take high doses of vitamin C at home, as it can cause digestive issues, such as diarrhoea.”
Ms Smith advised those thinking about upping their dosage of vitamin C to stick to a whole foods, healthy and balanced diet with plenty of fruit and vegetables such as citrus fruits, green leafy vegetables and even potatoes.
She added: “There is some research going on to see the effects of extremely high doses of IV vitamin C on coronavirus, however these trials are in the early stages and no conclusions can be drawn. Definitely don’t try this at home!”
While food can play an important role in optimising immunity, vitamin C cannot prevent nor treat coronavirus, Ms Smith explained.
The British Nutrition Foundation say that “no food or supplement, can protect you from getting the coronavirus (COVID-19)”, but added that “having a healthy diet is important in supporting our immune function and many nutrients influence the body’s ability to fight infection.”
Last week, Dr Andrew Weber, a pulmonologist and critical-care specialist in Long Island, said he had been giving his intensive care coronavirus patients 1,500 milligrams of intravenous vitamin C.
Identical amounts of the dosage are then re-administered three or four times a day, he told the New York Post.
“The patients who received vitamin C did significantly better than those who did not get vitamin C,” he said.
“It helps a tremendous amount, but it is not highlighted because it’s not a sexy drug.”
To strengthen the immune system naturally, Ms Smith said it is “better to get vitamin C from whole foods as opposed to supplements due to added benefits of nutrients such as antioxidants, which you can’t replicate in a supplement.”