Vitamin A Proof of Concept Study Post-Viral Olfactory Loss
Research type
Research Study
Full title
A Proof of Concept Study for Vitamin A Nasal Drops in Post-Viral Olfactory Loss
IRAS ID
294741
Contact name
Carl Philpott
Contact email
Sponsor organisation
University of East Anglia
Duration of Study in the UK
1 years, 10 months, 1 days
Research summary
Loss of smell affects an estimated 5% of people leading to depression, anxiety and isolation as well as changes in weight due to reduced appetite. Viral infections in the nose, including common colds and Covid-19, are the second most common cause of this smell loss. A recent limited study in Germany using vitamin A nasal drops showed that those in the treated group improved twice as much as those in the untreated group, lasting at least 10 months. It is thought that this treatment works to help repair tissues in the nose damaged by the viruses. This study will see if the size and activity of smell pathways in patients’ brains increases when they are treated with vitamin A nasal drops. This would show recovery of the damage caused by common viral infections in the nose.
We will invite people with smell loss due to a previous viral infection to join the study the Norfolk Smell & Taste Clinic or Fifth Sense (smell and taste disorders charity). Those able to join will be randomly allocated to one of two groups: 38 patients will receive a 12-week course of nasal vitamin A drops and 19 will receive a placebo (inactive drops). Both sets of patients will receive brain scans, before and after the treatment. We will look for changes in the size of the olfactory bulb (an area above the nose where the smell nerves join together and connect to the brain), that can be measured. We will also look at activity in areas of the brain linked to recognising smells. The patients will be smelling odours (roses and rotten eggs) while special brain scans are taken that use a magnetic coil to create images. A smell test and a questionnaire will also measure smell loss and its impact at the two visits.
REC name
West Midlands - Black Country Research Ethics Committee
REC reference
21/WM/0179
Date of REC Opinion
12 Aug 2021
REC opinion
Further Information Favourable Opinion