A team of U.K. researchers announced Tuesday they are investigating whether vitamin A nose drops can help coronavirus patients recover their lost or altered senses of smell, a common symptom of Covid-19 and other viral infections that can linger for weeks or months after infection.
- Vitamin A nose drops will be given to volunteer patients as part of a 12-week trial by the University of East Anglia (UEA), with the results compared to a group receiving a placebo of inactive drops.
- Previous research from Germany has “shown the potential benefit” of vitamin A in treating smell loss, UEA said, and the trial is designed to “explore how this treatment works to help repair tissues in the nose damaged by viruses.”
- As part of the trial, all participants will be asked to smell distinctive odors like roses and rotten eggs while undergoing special brain scans.
- The scans will be able to see whether the nerves involved in smelling have been repaired and detect brain activity linked to recognizing smells, explained UEA medical professor Carl Philpott.
- Philpott said around 1 in 10 Covid-19 patients who lost their sense of smell had not fully recovered four weeks after infection and said a “key problem” for patients and doctors is “the lack of proven effective treatments.”
- Philpott said the German study found that people treated with vitamin A “improved twice as much” as those who didn’t receive the treatment.
While smell loss was a significant problem before the pandemic—Philpott said it affected around 5% of people—Covid-19 triggered a huge surge in demand for treatments. “It’s a big problem,” Philpott said,” contributing towards issues including depression, anxiety, appetite changes and isolation. It also puts patients at risk of danger indicated by smell, Philpott added, including gas and spoiled food.
Smell loss is considered one of the “classic” symptoms of Covid-19, alongside a loss of taste, fever and a persistent cough. High numbers of Covid-19 patients lose their sense of smell and while it’s unclear exactly how many do, some studies indicate it is up to two-thirds. Some experience a distorted sense of smell, reporting foul odors to usually pleasant-smelling things. While most fully recover, the sensory issues can persist for weeks, months and possibly years in some patients, part of a post-viral syndrome known as long Covid. Though smell loss may seem relatively minor compared to some of Covid-19’s more serious, possibly life threatening symptoms, it has a profound effect on the lives of people experiencing it, their livelihoods and is tightly bound to other senses, especially taste. There are limited treatments for the condition. Steroids have been used, though they come with side effects and there is limited evidence they actually work. Doctors around the world have recommended smell training as an alternative, regularly smelling strong odors like coffee and garlic to retrain the brain to recognize different smells.