Iodine may reduce COVID symptoms

Posted on :  July 27, 2022

by Ashleigh Feltham
Accredited Practising Dietitian and Accredited Nutritionist

SARS-CoV-2, commonly referred to as COVID-19, has changed the world we live in.

The most effective way to reduce the symptoms and severity of this viral infection is through vaccination and safe practices like wearing a mask, good hygiene and physical distancing.

Not a lot is known about the effects of nutrition and the influence this may have on the severity of COVID-19. This may be about to change. New research is proposing iodine may have a positive effect in reducing the severity of symptoms and the rate of transmission among people.

COVID-19 is a virus that enters your lungs. One type of glycoprotein group found in the airways and saliva is called Lactoperoxidase (LPO). This group is responsible for inactivating foreign microorganisms in the body and as such is essential for a normal functioning immune system.

When iodine is present LPO forms a complex system of reactions called the duox-LPO system. The duox-LPO system ultimately results in a product called hypoiodite (IO−). IO− is lethal to viruses of the respiratory tract as it works as a potent, non-specific microbial agent. The duox-LPO system is considered a first line of defence for your body against respiratory virus infections.

Researchers have noted the COVID-19 rates in Japan are low. Despite the populated islands with close contact, there have been no strictly enforced lockdowns. When there is increased iodine present in the airways there has been an observed increase in the effectiveness of the duox-LPO system and its ability to destroy viruses.

The Japanese diet is known to be rich in seafood and seaweed and is consequently high in iodine. The average Japanese diet includes 300μg of iodine each day but under the upper daily limit of 1100μg. Other good sources of iodine can be found in dairy, bread (except organic bread, which is not required to be iodine-fortified) and eggs.

The need for iodine in our diet is transparently clear. A lifestyle approach of eating an overall balanced diet gives the body an optimal amount of iodine. This includes meeting recommended daily dairy and wholegrain serves each day and including bread as part of your whole grain choices. Including seafood two to three times a week, with a serving of seafood equal to 100g of cooked seafood. Eggs can be included as part of an overall balanced diet. If you have heart disease or type-2 diabetes, up to six eggs including the yolk a week is recommended. 

Take home message

The need for iodine in our diet is transparently clear and may reduce COVID Symptoms. The known protective methods to help reduce the transmission and severity of symptoms of COVID-19 still stands. This research serves as an additional component to consider and incorporate into your lifestyle, which may add additional protection against the severity of infection and rate of transmission of COVID-19. 

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  1. Sharma S, Singh AK, Kaushik S, Sinha M, Singh RP, Sharma P, et al. Lactoperoxidase: structural insights into the function, ligand binding and inhibition. Int J Biochem Mol Biol. 2013;4:108–28. 
  2. Bafort F, Parisi O, Perraudin JP, Jijakli MH. Mode of action of lactoperoxidase as related to its antimicrobial activity: a review. Enzym Res. 2014;2014:517164. 
  3. Geiszt M, Witta J, Ba J, Lekstrom K, Leto TL. Dual oxidases represent novel hydrogen peroxide sources supporting mucosal surface host defense. FASEB J. 2003;17:1–14. 
  4. Patel U, Gingerich A, Widman L, Sarr D, Tripp RA, Rada B. Susceptibility of influenza viruses to hypothiocyanite and hypoiodite produced by lactoperoxidase in a cell-free system. PLoS ONE. 2018;13:e0199167.
  5. Viswanathan V, Rani C, Ahmad N, Singh PK, Sharma P, Kaur P, et al. Structure of Yak Lactoperoxidase at 1.55 resolution. Protein J. 2021;40:8–18. 
  1. Fischer AJ, Lennemann NJ, Krishnamurthy S, Pocza P, Durairaj L, Launspach JL, et al. Enhancement of respiratory mucosal antiviral defenses by the oxidation of iodide. Am J Resp Cell Mol Biol. 2011;45:874–81. 
  2. Vural Z, Avery A, Kalogiros DI, Coneyworth LJ, Welham SJM. Trace mineral intake and deficiencies in older adults living in the community and institutions: a systematic review. Nutrients. 2020;12:1072. 
  3. Singh AK, Smith ML, Yamini S, Ohlsson P-I, Sinha M, Kaur P, et al. Bovine carbonyl lactoperoxidase structure at 2.0Å resolution & infrared spectra as a function of pH. Protein J. 2012;31:598–608. 
  4. Smith, M.L., Sharma, S. & Singh, T.P. Iodide supplementation of the anti-viral duox-lactoperoxidase activity may prevent some SARS-CoV-2 infections. Eur J Clin Nutr (2021).

Iodine may reduce COVID symptoms