A new study is considering treating those who have lost their sense of smell after having COVID-19 with vitamin A nasal drops, the University of East Anglia (UEA) said.

“The 12-week Apollo trial will treat people who have experienced a loss of smell or an altered sense of smell as a result of viral infections with nasal drops containing the vitamin,” the university said in a statement on Wednesday.

The university said research from Germany has shown the potential benefit of the vitamin.

It said its team would explore how this treatment works to help repair tissues in the nose damaged by viruses.

“The researchers hope the study could one day help improve the lives of millions around the world who suffer from loss of smell, by returning their fifth sense.

“It came after a study by an international group of smell experts, published in the journal International Forum of Allergy & Rhinology in April.

“It advised against using steroids to treat loss of smell and instead suggested “smell training,” it said.

Carl Philpott, from UEA’s Norwich Medical School and one of the researchers, said there was very little evidence that steroids will help with loss of smell.

He noted that steroids have potential side effects including fluid retention, high blood pressure and problems with mood swings and behaviour.

He recommended those who have experienced a loss of smell sniff at least four different odours, twice daily for several months.

Mr Philpott said the method aims to help recovery based on neuroplasticity, the brain’s ability to reorganise itself to compensate for a change or injury.

“Those interested in participating in the university’s vitamin A study are asked to seek a referral from their general practitioner to the Smell and Taste Clinic at the James Paget Hospital in Norfolk’s Great Yarmouth UK.

“The study, which is being funded by the National Institute for Health Research, will begin recruiting participants in December,” he said.