The pandemic has led to the identification of some promising nutraceuticals for the management and prevention of Covid-19. Nutraceuticals with their immune-boosting potential can amplify the body's defense system against the virus. For the past numerous decades, the medicinal action of natural compounds has gained focus as an alternate or adjuvant therapy approach in treating several diseases. Alongside bioactive substances contained in foods and natural substances are coined as nutraceuticals, show health benefits especially in the treatment of chronic illness. Nutraceuticals, obtained from natural sources have the advantage of negligible side effects when compared with other conventional drug therapies. This attracts consumers to lean on using nutraceuticals.1

Nutraceuticals are supplements with health benefits beyond their nutritional value. The use of nutraceuticals is not only for dietary supplementation but also aids in the prophylaxis and/or treatment of an illness or disorder. Considering this some nutraceuticals have exhibited therapeutic and preventive potential. They have been linked with antiviral and anti-inflammatory activities and prevention from acute respiratory distress syndrome (ARDS). The main nutraceuticals that are under evaluation for their potential preventive and treatment applications include omega-3 fatty acid, zinc, vitamin C, vitamin D, selenium.2

1. Omega-3 Polyunsaturated fatty acid (N-3 PUFA):

It contains eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Dietary intake of fish or another source of dietary supplementation with fish oil can fulfill the requirements of EPA and DHA. N-3 PUFA has a good medicinal effect against diseases that cause inflammation. It mediates inflammation by influencing processes like adhesion molecule expression and the production of eicosanoids.2 N-3 PUFA also suppresses the synthesis of immunoglobulin E, leading to reduced airway inflammation and bronchoconstriction in patients. Consumption of cod liver oil (contains EPA+vit A) leads to a decrease in complications associated with upper respiratory tract infection (URTI). Although these benefits of effective reduction in airway inflammation and bronchoconstriction, their potential use against covid-19 needs further investigation.3

2. Zinc:

Zinc supplementation has some benefits against RNA viruses. Zinc is a trace element that is vital for the maintenance of immune cells for adaptive and innate immunity against any viral infection. It boosts the host defense mechanism. Furthermore, zinc supplementation can increase the ability of natural killer cell levels, which is important for defense mechanisms. Adequate intake of zinc has been associated with reduced occurrence of infections and antiviral immunity. It has a property to inhibit the replication of viruses and for the same reason, it might be considered effective against replication of covid-19 virus as well.4

3. Vitamin C:

There are varieties of vitamins available in the market today, but vitamin C is proposed as an immunity booster against covid-19. In humans, it is identified that vitamin C improves the immune system by reducing oxidative stress in the lungs and whole body. It reduces the risk, severity, and duration of infectious diseases. Earlier evidence says that deficiency in water-soluble vitamin C can cause pneumonia. Whereas after administration of vitamin C in the infected patients, it has positive effects on the symptoms of respiratory tract infections. It prevents pneumonia and protects from other infections as well. In a new clinical trial, vitamin C is under investigation as severe cases of Covid -19 have shown to cause pneumonia. As there is the absence of specific drugs against SARS-CoV-2, vitamin C may show a ray of hope to cure this severe viral respiratory tract infection. Vitamin C increases the resistance against SARS-CoV-2 and shows improvement in lowering the spread of infection to lungs under certain conditions.1

4. Vitamin D:

Vitamin D, the sunlight vitamin has become a leading preventive measure and therapeutic nutraceuticals against covid-19. Vitamin D for many years has been in use for bone development and density. The active ingredient in vitamin D is calcitriol that influences many effects on the immune system and inflammatory response. Studies have shown that vitamin D improves lung function in children suffering from bronchial problems and reduces the chances of infection in them.4 Vitamin D inactive form is gets induced in respiratory pathway protecting it.1 Vitamin D is an immunomodulator of antigen-presenting cells. Because of its potential modulating properties, vitamin D supplementation may be advantageous to maintain a healthy immune system. Although the effectiveness of vitamin D supplementation against covid-19 remains open for debate.2

5. Selenium:

For increasing immunity against the covid-19 virus, it is important to showcase the benefits of selenium. The property of selenium is redox homeostasis and anti-oxidant properties against viral infections. Selenium deficiency in the body is known to cause impaired immunity against viral infections and flu. This deficiency turns out in the favour of viruses, which further increases their virulence and pathogenicity in the body. There is evidence suggesting that daily intake of supplementary selenium is beneficial in improving immunity against the deadly SARS-CoV-2 virus. 3

6. Glutathione:

Glutathione is a master of antioxidants in all tissues. It plays many roles like detoxification, antiviral defense, and immune booster. Oxidative stress has been associated with many lung-affected diseases. An oxidative stress level plays a vital role in the immune response to viruses. Viral infections cause inflammation due to reduced oxidative levels. Anti-oxidant therapies with N-acetylcysteine (NAC) have largely been used to treat bronchitis and glutathiones have been used locally in the treatment of lung diseases. Many studies suggest that glutathione can be restored oxidative levels and can be considered a treatment option for many respiratory infections. The oxidative stress in covid-19 is the currently prevailing hypothesis; hence this treatment approach can be considered. Considering, NAC is a substrate of glutathione a sufficient dose can be administered either for preventive or treatment action.

Nutraceuticals for boosting immunity in pregnant women

Pregnancy is a sensitive time for women. Any infection or disease is a big risk for the mother and baby. Pregnant women are more vulnerable to catch infections and get a disease. It is vital that a mother strengthens her immunity in every way she can as the viral infections are able to reach the fetus by crossing the placenta having bad consequences on the baby. Maternal immunity plays a critical role in maintaining and completing a healthy pregnancy for this a well-balanced diet is a must. Certain nutraceuticals are also considered safe for consumption during pregnancy like calcium, iron, magnesium, iodine, selenium, vitamin C, vitamin D, folic acid, and ginger. 5

Nutraceuticals for boosting immunity in children

The novel SARS CoV-2 is a virus for which no one has an in-built immunity. This fear has developed among parents. To boost your child's immunity against Covid-19, it is important that to breastfeed the baby during its early days to strengthen its immunity. Lack of nutrition can alter the immune response of children; hence nutrition is an important factor to be considered. A few immunity-boosting vitamins and nutraceuticals are available that are safe to use.

In a nutshell, many nutraceuticals are under evaluation for the treatment and prevention of Covid-19. Their positive results are attributed to their anti-inflammatory, antiviral, antioxidant, and immune-boosting properties. More clinical trials would help generate relevant efficacy and safety data that will support the claims of many nutraceuticals and help healthcare professionals in decision making. Clinical practitioners must be made aware of such alternative therapies for Covid-19.

References :

1)Infusino, Fabio et al. Diet Supplementation, Probiotics, and Nutraceuticals in SARS-CoV-2 Infection: A Scoping Review. Nutrients vol. 12,6 1718. 8 Jun. 2020.

2)Lordan R, Rando HM, Consortium CR, Greene CS. Dietary Supplements and Nutraceuticals Under Investigation for COVID-19 Prevention and Treatment. ArXiv [Preprint]. 2021 Feb 3:arXiv:2102.02250v1. PMID: 33564696; PMCID: PMC7872359.

3) Users/user/Downloads/ijfn_1_2_6_PDF.pdf

4)Parisi GF, Carota G, CastruccioCastracani C, Spampinato M, Manti S, Papale M, Di Rosa M, Barbagallo I, Leonardi S. Nutraceuticals in the Prevention of Viral Infections, including COVID-19, among the Pediatric Population: A Review of the Literature. Int J Mol Sci. 2021 Feb 28;22(5):2465.

5)Pregnant woman should strengthen their immunity during covid-19; Dr. Anish Desai.

6)Silvagno, Francesca et al. The Role of Glutathione in Protecting against the Severe Inflammatory Response Triggered by COVID-19. Antioxidants (Basel, Switzerland) vol. 9,7 624. 16 Jul. 2020.

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