They are giving mega-doses—up to 24g—intravenously to coronavirus patients to see if it reduces the symptoms and speeds recovery. The dose is 400 times the dose recommended for maintaining general health and preventing scurvy.

Covid-19 is a new virus that was identified only last January following a mysterious outbreak of pneumonia in the Wuhan province of China last December; no antiviral has been found to treat it, and a vaccine to prevent it is still 18 months away.

But the researchers from Zhongnan Hospital say there is evidence that vitamin C deficiency increases the risk of contracting influenza viruses and makes symptoms more severe.

Vitamin C (ascorbic acid) has antioxidant qualities that can prevent damage to the lungs, one of the symptoms of the coronavirus, says lead researcher ZhiYong Peng.

He will be testing the mega-dose treatment until September by when he will have treated 140 coronavirus patients, either with the vitamin C dose given intravenously every day for seven days or instead with a water-based placebo.