Study Shows Vitamin A May Be the Key to Bring Back a Lost Sense of Smell


John Oh, Forum Writer

Vitamin A nasal drops may not be the cure but be the supporting supplement to help other treatments cure the loss of smell caused by viruses such as Covid-19.

On Sept 29, BBC news uploaded an article about the Vitamin A Treatment Trial that is currently taking place at the University of East Anglia. 

The article states that vitamin A could possibly be the treatment for olfactory dysfunction caused by the Covid-19.

Covid – 19 causes olfactory dysfunction because the olfactory receptor in olfactory nerve epithelial cells is susceptible to viral infection. 

The two main causes are direct damage on the olfactory receptor neurons located in the epithelium and the cytokine storm which is excessive or uncontrolled production of immune cells which can lead to smell sensory organ damage.

According to the National Library of Medicine, vitamin A plays a decisive role in regenerating the olfactory receptor neurons which are the sensors that detect traces of chemicals in the inhaled air that allows us to smell.

However, lead scientist of KYM Biomedical Research Dr. Jongchul Kim states that vitamin A wouldn’t provide enough of a difference to treat olfactory dysfunction completely and efficiently.

“In animal studies, vitamin A has been proven to stimulate the immune response of the olfactory epithelium to help restore the damaged olfactory system, but no significant effect was found in humans” said Kim 

Although vitamin A enhances the immune system, it wasn’t enough to make a significant difference. However Kim suggests that vitamin A should still be used.

“In terms of olfactory dysfunction treatment, vitamin A is not the best but we may consider combination treatment with others. I believe that vitamin A can play an important role as a supplement in the treatment of olfactory disorders.” said Kim.

Vitamin A, although it may not be the best treatment by itself, its ability to increase activity of the immune system can help other treatments such as olfactory (smell) training have a greater effect than used alone.

In a case report, one patient received a combination of oral vitamin A and smell training and it resulted in a successful treatment and had better results than when the two techniques were used separately.

Dr. Kim continues and gives a list of the possible treatments for the dysfunction.

“Other possible treatments are systemic steroids, topical steroids, minocycline, caroverine, alpha lipoic acid and zinc sulfate.” said Kim.

All of the above have their benefits and harms. For example, systemic steroids have improved objective olfaction across multiple psychophysical tests but they have potential side effects relating to systemic corticosteroids.

However, Dr Kim states that the best treatment that is possible currently is the olfactory training.

Smell training started in 2009 by Dr. Hummel Et Al. This training works by stimulating the brain to process and build back its senses by smelling 4 different objects for 10 seconds every morning and afternoon.

In conclusion, olfactory (smell) training supported by supplements is most likely the best option for the treatment of olfactory dysfunctions caused by viruses.