1. bookTom 76 (2022): Zeszyt 1 (January 2022)
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eISSN
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20 Dec 2021
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A review of natural foods consumed during the COVID-19 pandemic life

Data publikacji: 29 Jun 2022
Tom & Zeszyt: Tom 76 (2022) - Zeszyt 1 (January 2022)
Zakres stron: 188 - 198
Otrzymano: 11 May 2021
Przyjęty: 16 Nov 2021
Informacje o czasopiśmie
License
Format
Czasopismo
eISSN
1732-2693
Pierwsze wydanie
20 Dec 2021
Częstotliwość wydawania
1 raz w roku
Języki
Angielski
Abstract

Coronavirus 2019 (COVID-19) is an infectious disease that has brought life to a standstill around the world. Until a vaccine was found to combat COVID-19, the world conducted research and made recommendations for nutritional natural foods. Considering the risks incurred by contracting the disease, even though the production of various vaccines and vaccination of healthy people has started in some countries, individuals need useful foods to be ready for the COVID-19 pandemic. Recently, nutrient contents such as antioxidant compounds, vitamins, minerals, and probiotics that contribute to the immune system have been investigated. This paper attempts to determine the role of these dietary supplements in reducing the risk of COVID-19 and/or changing the course of the disease in COVID-19 patients and their effects on mortality. Supplements used and recommended for the COVID-19 pandemic life were investigated. In conclusion, more research is needed to determine the effectiveness of nutrients, vitamins, minerals, probiotics, prebiotics, and antioxidants used during the COVID-19 pandemic to inhibit the effect of SARS-CoV-2. In order to overcome the new global crisis, nutritional cures and treatments should be upgraded. However, additional research on the subject is needed.

Keywords

Introduction

In December 2019, an outbreak of pneumonia of unknown cause took place in Wuhan, China. Chinese health authorities took action to determine the cause and to control the infection, including isolation of people suspected of having the disease, close observation of contacts, collection of epidemiological and clinical information from patients, and improvement of diagnosis and control [1]. Studies found that there is a new beta coronavirus (β CoV) called critical acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to its phylogenetic similarity with SARS-CoV. Infections spread to the rest of the world, leading to the WHO announcement of a pandemic and a Public Health Emergency of International Importance (PHEIC) [2, 3, 4]. COVID-19 is reported to be more severe and higher in mortality in older patients with conditions such as diabetes and hypertension, and in people with impaired immune systems [3, 5].

The number of Covid-19 cases was determined to be 30,000,000 worldwide in September 2020, and the number of deaths on the same date was reported to be over 940,000 [6]. As of February 7, 2021, a total of 106,404,126 laboratory-confirmed cases and 2,321,761 deaths had been documented globally [7].

In studies, vitamins (B12, C, D, E) and trace elements (zinc, selenium, magnesium, and copper) to support the immune system were determined to be important [8, 9, 10]. Inadequate intake of these nutrients is common. Malnutrition causes suppression of the immune system, a decrease in resistance to infections, and an increase in disease burden [8].

In research, some nutrients that may be useful in the treatment of COVID-19 have been reported: zinc, resveratrol, hydroxytyrosol, curcumin, quercetin, vitamin C, and vitamin D [11]. In diabetic people who were hospitalized with COVID-19, inadequate long-term glucose control was positively and independently related with tracheal intubation and/or death within 7 days [12]. One study examined the relationship between dietary diversity of countries and COVID-19 mortality rate. When Germany was examined, consumption of a higher fat diet was reported in the southern states. It has been stated that the diet pattern differs according to the regions. The southern states traditionally have a higher-fat diet. Regional dietary differences and mortality rates are also different, suggesting that they are related. Therefore, differences in nutrition between countries with low and high mortality rates have been investigated. It has been determined that foods with high antioxidant or anti-ACE activity (raw or fermented foods) are consumed more in low-mortality European countries, and Korea and Taiwan. Cabbage is widely consumed in Romania and fermented milk in Bulgaria and Greece: it has been reported that lower mortality rates can be associated with these diets. Turkey is another country with low mortality rates, where fermented cabbage is widely consumed. Information like this shows that although diet has an effect on prevention of the COVID-19 outbreak, further studies are needed to know its importance [13]. It is reported that individuals aged 60 and over are most affected by COVID-19 all over the world. It was determined that mortality rate increased with increasing age due to comorbid diseases [14].

All these results showed that nutrition is a very important subject in COVID-19 disease. Nutritional supplements, recommendations, and researches have been explored in the pandemic.

Vitamin and Mineral Supplements
Vitamins
Vitamin B12

Vitamin B12 deficiency is a common condition in both elderly and diabetic patients. The importance of folate, homocysteine, and B12 in single carbon metabolism is known. In a study examining the effect of COVID-19 on the elderly and diabetic patients, the role of vitamin B12 deficiency was investigated. It has been shown in a study that areas where the negative effects of B12 deficiency and incidence of COVID-19 coincide. There is also evidence that COVID-19, which causes problems in immunological, microbiological, hematological, and endothelial cell functions, can add a potential therapeutic dimension by interfering with its replication with B12 supplements. For this reason, it is stated that B12 deficiency is a modifiable and absolutely preventable risk factor in the fight against COVID-19. As a result, researchers have found that the folate, homocysteine, and B12 levels of COVID-19 patients should be optimized [15].

Studies have found [16, 17, 18] that high serum vitamin B12 is associated with increased mortality in critically ill patients. It has been suggested that vitamin B12 levels should be determined, especially in intensive care patients with chronic disease and increasing disease severity [18].

Vitamin C

The antiviral property of vitamin C has been found in researches with patients affected by various types of herpes or influenza viruses. In addition, people who have acute infectious diseases have been reported to have low serum vitamin C levels. Ascorbate has been shown to have the capacity to increase interferon production and reduce the production of different cytokines. Vitamin C also provides positive effects in terms of immunomodulation in patients affected by different viral infections [19].

In a different study, methemoglobin, nitrite, nitrate, and prooxidant-antioxidant levels were determined in 25 healthy individuals and 25 patients hospitalized in the COVID-19 intensive care unit. It was determined that methemoglobin, nitrite, nitrate, and oxidative stress were importantly enlarged in COVID-19 positive patients compared to healthy individuals. Methylene blue-vitamin C-N acetyl Cysteine (MCN) was administered to 5 patients as the last treatment option. It was determined that four out of five patients responded well to treatment. As a result, it has been determined that nitric oxide, methemoglobin, and oxidative stress may play a central role in the pathogenesis of critical COVID-19 disease; moreover, MCN therapy can increase the survival rate of patients [20].

A review study established that the use of high doses of oral vitamin C provided protection against viral infections. It has been stated that antioxidants such as vitamin C can be used in high doses for treatment of early-stage COVID-19 patients. Intravenous or oral administration of high doses of vitamin C has been shown to be safe. Therefore, including vitamin C in COVID-19 treatment is recommended [21].

Fig. 1

Some suggested important natural foods effective against COVID-19

Vitamin D

Vitamin D is one of the fat-soluble vitamins. In the form of vitamin D2 (ergocalciferol), it can be taken by consuming dairy products, fish, and eggs. Under the influence of the sun, vitamin D3 (cholecalciferol) can be converted into 1,25-dihydroxycholecalciferol (calcitriol), which is the active form of vitamin D in the skin. It plays a role in the absorption of vitamin D, calcium, magnesium, and phosphate [22].

Vitamin D plays an important role by interfering with most of the macrophages, B and T lymphocytes, neutrophils, and dendritic cells in the immune system [23]. Additionally, vitamin D deficiency been found to be involved in various diseases such as diabetes, changes in regulation of immune system, cardiovascular diseases, cancer, inflammation, hypertension, cognitive changes, and osteoporosis [22]. During the pandemic, the level of exposure to sunlight decreases as time spent by individuals in the open air decreases [24, 25, 26]. Lower serum vitamin D levels are reported to be associated with psychiatric illnesses, including autism and major depressive disorders (MDD) [27, 28]. Different amino acids and vitamin D are known to be precursors and regulators of mental well-being [29].

Low serum vitamin D is common in Europe, with the exception of the Nordic countries. It is reported that 12 European countries show a significant (P = 0.046) inverse correlation with the COVID-19 mortality rate, plasma 25 (OH) D concentration [30].

If vitamin D deficiency is accompanied by comorbidities such as hypertension, diabetes, cardiovascular diseases, and metabolic syndrome, closer follow-up of COVID-19 patients is recommended. It has been determined that the natural vitamin D synthesis of the skin is reduced, especially as the exposure time of people to the sun decreases due to the pandemic. It is recommended that individuals consume vitamin D–fortified foods if they have access to them. It is emphasized that the vitamin D level of COVID-19 patients staying in hospital must be measured and supplemented with supplements if low [23].

The possible role of vitamin D in providing immune response in viral infection becomes even more important in the pandemic. In addition, dexamethasone is used as an anti-inflammatory drug in COVID-19 patients with critical disease. It has been emphasized that large-scale studies should be carried out on whether vitamin D can be used in combination with dexamethasone or alone in reducing the effects of viral infection [31].

Another descriptive retrospective study was conducted in a health center with COVID-19 patients in Tehran, Iran, between March and April 2020. In this study, in which a total of 205 patients were examined, no statistical difference was found between the serum vitamin D levels of COVID-19 patients who died in hospital and those who recovered. When the patients were grouped according to disease level, it was determined that there was a significant difference in serum vitamin D level in patients with severe disease, healing, and death (P value: 0.021). In addition, it was emphasized that the mortality rate was higher in patients with very low vitamin D levels. It was concluded that vitamin D deficiency may affect the control of the disease and mortality in individuals, especially if there is an accompanying disease or the individual is elderly [32].

In a study conducted in Italy, serum 25 (OH) vitamin D levels of 129 adult COVID-19 patients hospitalized in the health center between March and April 2020 were evaluated. No correlation was found between COVID-19 and serum 25 (OH) vitamin D deficiency (< 20 ng/mL) in the research. Contrary to expectations, a significant positive association was observed between increased serum 25 (OH) vitamin D level and mortality [33].

Another retrospective study was conducted in medical centers in Boston and New York. Serum 25 (OH) D levels of COVID-19 positive patients are inversely correlated with mortality and the need for invasive mechanical ventilation. It was emphasized that randomized clinical studies are needed to evaluate the effects of vitamin D in reducing morbidity and mortality of COVID-19 [34].

In a study examining the relationship between vitamin D status and disease severity and mortality, 185 patients diagnosed with COVID-19 and treated in the center where the study was conducted were examined. In this observational study, it was determined that there is a relationship between vitamin D status and the severity and mortality of COVID-19. It has been emphasized that prospective, randomized controlled trials on vitamin D supplementation in COVID-19 patients are highly warranted [35].

A retrospective, observational study conducted in the United States was conducted between March and June 2020. In this study, which included 191,779 patients from all 50 states, an inverse relationship was observed between SARS-CoV-2 positivity and circulating 25 (OH) D levels. According to the results, vitamin D supplementation has been reported to be required to reduce the risk of COVID-19 infection [36].

Vitamin E

Vitamin E, one of the fat-soluble vitamins, shows an important role in decreasing oxidative stress [37]. Vitamin E deficiency increases the symptoms of diseases and causes critical conditions. An inverse correlation was found between vitamin E and viral infection. Therefore, improving vitamin E status is suggested to decrease the harmful effect of oxidative stress in patients with COVID-19 disease [38].

Vitamin K

Vitamin K is a biochemically single functional nutrient, because its only defined function is γ-carboxylation. However, it has been determined to activate proteins with yet not fully resolved functions [39]. In a study, it was reported that vitamin K decreased in COVID-19 patients and this decrease was related to poor prognosis. This study states that new studies are required to determine the effect of vitamin K administration on patients with COVID-19 [40]. In another study, it is reported that small intestine involvement and/or decreased dietary intake due to COVID-19 may be among the causes of decreased vitamin K status in COVID-19 patients. Among other potential reasons, decreased access to green leafy vegetables is cited as a possible cause, as was increased alcohol consumption and increased use of paracetamol [41].

Minerals
Zinc

Zinc is an essential mineral that serves as a cofactor in most intracellular processes. Additionally, it plays a role in cell functions. It can be related to metabolism and immune system function. It is estimated that about 20% of the world's population has low blood zinc levels. It is also reported that blood zinc level is more important for the elderly. It has been determined that zinc deficiency causes a decrease in antibody production. In zinc deficiency, the activity of natural killer cells decreases and the innate immune system changes [11].

Selenium

Selenium is an essential trace element. Along with vitamin E, selenium prevents free radical formation and oxidative damage in cells and tissues. It has been found to have an effect on immune response [42]. It has been reported that selenium deficiency may be responsible for lung damage and may be associated with mutation of viral genomes [43]. Inadequate intake of selenium, an antioxidant nutrient, with nutrition causes diseases or death by leading to immune system impairments and RNA viral mutations [44].

Magnesium

In the observational cohort study, 43 COVID-19 patients 50 years old were identified and 17 patients were given vitamin D3 1000 IU OD, magnesium 150mg OD and vitamin B12 500mcg OD (DMB). Supplements were not given to the remaining 26 patients. DMB supplementation administered to COVID-19 patients depending on age has been related to a significant decrease in the proportion of patients needing oxygen and/or intensive care support. Studies in larger groups have been suggested to confirm the benefit of DMB [45].

Probiotic, prebiotic, and fermented products

Prebiotics are substances used by microorganisms living in the body which positively affect health. Consumption of prebiotics promotes the growth of Bifidobacterium in the gut and modulates the B-cell response. It increases NK cell activity, Th1-dependent immune responses and interferon production. Similar to probiotics and prebiotics, postbiotics have recently been defined as bioactive compounds produced temporarily during a fermentation process that promotes health and/or well-being. Their mechanism of action has not been fully determined, but it is thought to be an immunomodulator [46].

Probiotics colonize mainly in the intestine. However, these enities have been determined to have a fundamental effect on the immune system. They also play a role in the emergence of immune responses in the lung and other mucosal areas [47]. Studies have found that prebiotic consumption is as important as probiotic consumption for immunity. A healthy diet rich in prebiotics, such as fibers, fruits, vegetables, and whole grains, is essential for properly nurturing probiotics and for the proper functioning of the immune system [48].

Prebiotics are derived from plants such as Jerusalem artichoke, chicory root, yacon (source of inulin), onions, whole grains, garlic, and bananas. Dietary fiber that is water-soluble and digested by intestinal bacteria, and those that are fermented in the large intestine, such as water-insoluble but resistant starches, have been termed prebiotics. Commonly used prebiotics are fructo-oligosaccharides/oligofructose (FOS), galacto-oligosaccharides (GOS), inulin, isomalto-oligosaccharide (IMO), beta-glucan, and psyllium husk [49].

Probiotics taken with the consumption of dairy products have many functions in intestinal health, such as strengthening the immune system and increasing the bioavailability of foods [50]. Probiotics are known to help protect the gut microbiome. They aid the immune system in the formation of the response to diseases [51].

Fecal samples of COVID-19 patients have been studied. SARS-CoV-2 viral RNA appears in the gut of patients. Therefore, gut health is thought to be important for COVID-19 [48]. Probiotics are recommended against COVID-19 because they regulate the intestinal-lung axis, have positive effects on innate/developable immunity, and they are required in regeneration of damaged tissues and organs [47, 50, 52].

In addition to Lactobacillus and Bifidobacteria; Saccharomyces boulardii and Bacillus types are also widely used as probiotics [53]. The effects of Lactobacillus gasseri among lactobacilli on different viral infections including respiratory infections has been determined in studies [54, 55]. In a review study, the relationship between intestinal purine metabolism and the use of Lactobacillus gasseri was investigated. Low-purine diets help treat COVID-19 by improving immunity and increasing antiviral effects [53].

Although good vaccines for COVID-19 are now available, an immune-boosting diet containing prebiotics and probiotics is recommended [56].

In another review study, it was stated that the use of probiotics in COVID-19 should not be recommended until its effect on SARS-CoV-2 pathogenesis and intestinal microbiota is determined. With this work to be done, it is thought that new suggestions will be presented for the change of intestinal microbiota against COVID-19 and accompanying diseases [57].

In a case-control study conducted with 505 participants (226 controls and 279 subjects with clinical symptoms of COVID-19) in Iran, the eating habits of the control group and the patient group were examined. The consumption of doogh drink and yogurt was found to have a protective role in the occurrence of COVID-19. Individuals at high risk for COVID-19 have been advised to consume adequate amounts of yogurt and doogh drink during the pandemic [58].

The use of fermented foods, probiotics, and/or prebiotics is recommended to protect intestinal health and increase immunity. Consumption of probiotics and prebiotics is thought to help reduce intestinal inflammation and strengthen immunity. Fermented foods and probiotics contain live microorganisms with the potential to boost (intestinal or systemic) immunity. It is reported that prebiotics can increase intestinal immunity by selectively stimulating microorganisms in the intestine. For this reason, it is reported that beneficial microorganisms may be important in the prevention of COVID-19 and other infectious diseases that may occur in the future [59].

Foods that contain organosulphur compounds
Onion

It has been determined that the content of all onion species is rich in flavonols such as quercetin, tannins, kaempferol, allyl propyl disulfide and diallyl disulfide [60]. Onion has been used as a traditional medicine for thousands of years [61].

According to the results of a study, onion consumption may have an antithrombotic, anti-inflammatory and possibly anti-viral effect in the primary treatment of COVID-19 patients. The study noted that further researches are needed to determine the useful effects on COVID-19 [62].

It has been determined that kaempferol and quercetin contained in onions reduce the growth of various viruses. In addition, virucidal activities of quercetin and kaempferol against herpes simplex type I virus, rabies virus, mengo virus, polio virus, sindbis virüs, pseudorabies virus and parainfluenza type 3 virus were determined in studies. Numerous previous studies have noted the antiviral effect of onion and garlic [63]. In another study based on these results, onion and garlic consumption is recommended to prevent COVID-19 disease [64].

Garlic

Garlic (Allium sativum L.) is one of the oldest herbs used as food and medicine. The antibiotic effect of garlic (Allium sativum L.) has been known for a long time [65]. The immunomodulatory, antitumor, anticancer, antidiabetic, anti-atherosclerotic, anti-inflammatory and cardioprotective properties of the phytochemicals found in garlic (Allium sativum L.) have been determined [65, 66]. Natural garlic contains high concentrations of organic sulphur compounds [65]. Flavonoid (quercetin) and organosulphur (allicin and aline) compounds provide the immunomodulatory effects of garlic. It is emphasized that garlic inhibits COVID-19 with its antiviral properties. For this reason, it is thought that daily consumption of garlic alone or in combination with drugs can reduce the side effects and toxicity of drugs [67].

Research was conducted to determine the resistance of compounds in garlic essential oil to SARS-CoV-2. The strongest anticoronavirus effect has been found in allyl disulfide and allyl trisulfide compounds. Allyl disulfide and allyl trisulfide are the most dominant compounds in garlic essential oil [68].

Some special supplements
Quercetin

Quercetin is one of the flavonols and six subfamilies of flavonoids. It is the most dominant flavonoid molecule found in various vegetables and fruits such as apple, onion, dill, strawberry, and coriander. It is a yellow compound that can be soluble in lipids and alcohol. Many useful pharmacological activities of quercetin have been reported. Among them, anticancer capacity and ability to fight viruses can be highlighted. In addition, it has been reported that it has positive impacts in the treatment of allergic diseases, cardiovascular disorders, metabolic diseases and inflammation [69].

Quercetin can inhibit the entry and replication of influenza virus, Dang virus, and enterovirus into host cells [63, 70]. According to the data of another study, it was determined that quercetin can inhibit the replication of different respiratory viruses [71, 72]. It was theoretically determined that quercetin would interfere with the replication of SARS-CoV-2 [73].

While it is thought that the use of quercetin may have a positive effect on the incidence and duration of respiratory tract infections, in another study, it is emphasized that more research is needed to determine its use in the treatment of COVID-19 [74].

Resveratrol

Resveratrol is in the the polyphenol family and is found in grapes, strawberries, nuts, red wine, chocolate, and similar foods. Resveratrol is known to protect against a range of diseases, including respiratory, malignant, and cardiovascular diseases [75]. In the cellular stage, resveratrol shows as an cytostatic, anti-oxidant, antiviral, anti-inflammatory, and it extends the lifespan of cells [76].

Antiviral properties of resveratrol against various viral pathogens have been established. Positive results have been determined in in vitro and in vivo studies on diseases such as Middle East Respiratory Syndrome Coronavirus (MERS-CoV) [77], duck enteritis virus [78], and pseudorabies virus [79, 80]. In a study, it was emphasized that resveratrol, which is naturally found in many fruits, is expected to decrease mortality caused by COVID-19 with its anti-inflammatory and anti-thrombotic properties [81].

A study was conducted with 230 severe COVID-19 patients between April and May 2020 at a hospital in Mumbai. Thirty patients were given resveratrol and copper in addition to care. According to the results of the study, the use of resveratrol-copper combination resulted in a twofold reduction in mortality. It was stated that new randomized controlled studies should be conducted in addition to this study [82].

Curcumin

Curcumin is found in the turmeric plant, and has long been used in food. Due to its proven antiviral properties, use of it has become widespread [83]. It has been established that it can affect the cell metabolism and organisms in different ways, including anti-oxidant, anti-inflammatory and anti-proliferative properties [84]. Previous studies have established antiviral properties against many viruses, including HIV [85], dengue [86], herpes simplex [87], and hepatitis C virus [84, 88]. Another study found its antiviral effect on mosquito-borne Zika and Chikungunya viruses [83].

Curcumin, zinc, and zinc-ionophores were also investigated in studies. Antiviral effects against viral infections have been determined. Curcumin can form ionophore complexes with polyphenols such as zinc. It has been reported that zinc, curcumin, and zinc-ionophores can be used in immune support and in the treatment of COVID-19 using various mechanisms [89, 90].

A study was conducted on isolated probiotics derived from traditional Indian (turmeric) pickles used in the process of the COVID-19 outbreak. The study found that the turmeric in fermented pickles is a good probiotic candidate and is recommended as a very beneficial product for health [91].

Homocysteine

Homocysteine is an amino acid that contains a sulfhydryl group. It is found during the metabolism of the amino acids methionine and cysteine. Hyperhomocysteinemia is used as a predictive risk indicator in screening congenital methionine metabolism, in the detection of cardiovascular diseases and vitamin B12 deficiency. Homocysteine shows the most negative effects in the cardiovascular system and nervous system [92].

Previous studies have shown that hyperhomocysteinemia has adverse effects on many viral infections, including human hepatitis virus, human papilloma virus [93], and human immunodeficiency virus [94]. In addition, the emergence of hyperhomocysteinemia not only in COVID-19 patients but also in many other diseases may have a negative effect, but the results have not been determined [95].

In a study of 40 individuals with COVID-19, routine detection of plasma homocysteine as a potential indicator for disease was performed, and found to be useful. Sharing first observations about the potential biomarkers for serious diseases during the pandemic will provide important benefits for patients and rapid development of available information [96]. It has been reported that if COVID-19 is present with harmful hyperhomocysteinemia in patients, it is thought that the use of vitamin B9 and other B vitamins is positive and safe in lowering the homocysteine level. B vitamins may be temporarily preferred for treatment. However, in the same report, it was stated that more studies are needed on this subject [95].

Propolis

Propolis is widely used in health promotion and strengthening the immune system. Propolis produced by bees has antiviral activity [97]. Propolis is an auxiliary ingredient in traditional Chinese medicine [93]. It has also been identified as an immunostimulating and powerful vaccine adjuvant [98].

It has been observed in studies that propolis has antiviral and anti-inflammatory [99, 100] properties. In other researches, it was determined that propolis has an inhibition effect on influenza [100, 101] and herpes simplex virus type 1 [99]. It is found that propolis may also have an antiviral effect against SARS-CoV-2 [97].

Green tea

In a study, the antiviral activities of theaflavins in black tea and epigallocatechin-3-gallate (EGCG) polyphenols in green tea were examined. The antiviral activity of epigallocatechin-3-gallate (EGCG) against several viruses has been established. It has been found to be an important treatment option compared to chemical drugs [102]. Apart from antiviral effects, antibacterial, antitumorigenic, antioxidant, anti-inflammatory, and antiproliferative properties have been observed [103]. Theaflavins (TF) are found in black tea. The anti-inflammatory, anti-tumor, anti-bacterial, anti-oxidative and anti-viral properties of theaflavins have been determined. Both green tea and black tea polyphenols have anti-viral activities against various viruses, especially single-stranded RNA viruses. When studies are reviewed, the use of tea polyphenols is recommended in the treatment of COVID-19 [102].

In a review article, it was stated that in countries where large amounts of green tea is consumed, such as China, Indonesia, and Japan, the mortality rates are lower than in Europe, Africa and the USA [104].

Various effects of natural micronutrients and bioactive substances

Effects Micronutrients References
Anti-inflammatory Vitamin D, Curcumin, Quercetin, Propolis [99, 100, 105, 106, 107]
Antioxidant Vitamin C, Vitamin E, Curcumin, Selenium [37, 106, 108, 109]
Antiviral Selenium, Curcumin, Quercetin, Riboflavin, Vitamin C, Green Tea, Propolis, Resveratrol, Zinc [99, 100, 103, 109, 110, 111, 112, 113]
Immune response Vitamin A, Vitamin C, Vitamin D, Vitamin B12, Folate, Pyridoxine, Zinc, Nicotinamide, Selenium [38, 109, 113]
Interferon production Vitamin C [111]
Virus-ACE2 interaction reduction Quercetin, Curcumin [11]
Nutrition recommendations of health institutions

It was stated that among the nutritional recommendations published by the World Health Organization (WHO) for adults during the COVID-19 pandemic process, unprocessed foods and fresh vegetables and fruits should be consumed daily. It was emphasized that 8–10 glasses of water should be consumed every day, less salt and sugar should be consumed, and fat and oil consumption should be moderate. In addition, it has been suggested that meals should be consumed at home to reduce exposure to COVID-19 [114].

Nutritional recommendations of ASPEN for COVID-19 patients are 3 liters of fluid consumption per day, a diet containing 2000–2500 calories and 75–100 grams of protein. It was emphasized that even if the patient is not hungry, food should be consumed every 2–3 hours [115].

According to the ASPEN recommendation, patients receiving enteral nutrition should be targeted to meet 70% to 80% of their daily energy needs (15 to 20 kcal/kg actual weight) and 1.2 to 2 grams of protein/kg per actual weight [116].

It has been reported by ESPEN that energy intake should be 27–30 kcal/day during the COVID-19 period (determined according to nutritional status, weakness, polymorbid status). Protein intake has been suggested to be 1 g/kg/day. It has been stated that fat and carbohydrate consumption should be 30–70% or 50–50% in patients with respiratory problems. It has been reported that adequate intake of vitamins A, E, B6 and B12 and micronutrients such as Zn and Se should be considered [117].

Conclusions

The prevalence of obesity and type 2 diabetes is high, as diets high in saturated fat, refined carbohydrates, and sugar are common worldwide. Individuals with comorbidities are reported to have a higher mortality rate from COVID-19.

Elderly patients and patients with concomitant illnesses mostly had impaired nutritional status and sarcopenia, independent of body mass index. Increased body mass index appears to be associated with poor prognosis in the presence of comorbidity in COVID-19 patients. As a result, the importance of nutrition has been observed in studies on COVID-19 patients. It was stated that the nutritional therapies and the treatment to be applied should be improved in order to overcome the new global crisis.

Adequate and balanced diet, avoidance of processed foods, and consumption of healthy foods are very important in COVID-19, as in many diseases. In the long run, new studies should be conducted with more people to determine the safest and most effective dietary supplements for COVID-19.

Fig. 1

Some suggested important natural foods effective against COVID-19
Some suggested important natural foods effective against COVID-19

Various effects of natural micronutrients and bioactive substances

Effects Micronutrients References
Anti-inflammatory Vitamin D, Curcumin, Quercetin, Propolis [99, 100, 105, 106, 107]
Antioxidant Vitamin C, Vitamin E, Curcumin, Selenium [37, 106, 108, 109]
Antiviral Selenium, Curcumin, Quercetin, Riboflavin, Vitamin C, Green Tea, Propolis, Resveratrol, Zinc [99, 100, 103, 109, 110, 111, 112, 113]
Immune response Vitamin A, Vitamin C, Vitamin D, Vitamin B12, Folate, Pyridoxine, Zinc, Nicotinamide, Selenium [38, 109, 113]
Interferon production Vitamin C [111]
Virus-ACE2 interaction reduction Quercetin, Curcumin [11]

Wang C, Horby PW, Hayden FG, Gao GF. A novel coronavirus outbreak of global health concern. Lancet. 2020; 395: 470–473. WangC HorbyPW HaydenFG GaoGF A novel coronavirus outbreak of global health concern Lancet 2020 395 470 473 10.1016/S0140-6736(20)30185-9 Search in Google Scholar

Martinelli SS, Cavalli SB, Fabri RK, Veiros MB, Reis ABC, Amparo-Santos L. Strategies for the promotion of healthy, adequate and sustainable food in Brazil in times of Covid-19. Rev Nutr. 2020; 33: e200181. MartinelliSS CavalliSB FabriRK VeirosMB ReisABC Amparo-SantosL Strategies for the promotion of healthy, adequate and sustainable food in Brazil in times of Covid-19 Rev Nutr 2020 33 e200181 10.1590/1678-9865202032e200181 Search in Google Scholar

Mohamed Khosroshahi L, Rokni M, Mokhtari T, Noorbakhsh F. Immunology, immunopathogenesis and immunotherapeutics of COVID-19; an overview. Int Immunopharmacol. 2021; 93: 107364. Mohamed KhosroshahiL RokniM MokhtariT NoorbakhshF Immunology, immunopathogenesis and immunotherapeutics of COVID-19; an overview Int Immunopharmacol 2021 93 107364 10.1016/j.intimp.2020.107364778453333486333 Search in Google Scholar

Yadav VK, Singh G, Jha RK, Kaushik P. Visiting Bael (Aegle marmelos) as a protective agent against COVID-19: A review. Indian J Tradit Know. 2020: 5. YadavVK SinghG JhaRK KaushikP Visiting Bael (Aegle marmelos) as a protective agent against COVID-19: A review Indian J Tradit Know 2020 5 10.56042/ijtk.v19i0.35536 Search in Google Scholar

Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui DSC, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med. 2020; 382: 1708–1720. GuanWJ NiZY HuY LiangWH OuCQ HeJX LiuL ShanH LeiCL HuiDSC Clinical characteristics of coronavirus disease 2019 in China N Engl J Med 2020 382 1708 1720 10.1056/NEJMoa2002032709281932109013 Search in Google Scholar

Weber TK, Leandro-Merhi VA, Bernasconi I, Oliveira MRM de. Nutritional therapy in hospital care of in-patients with Covid-19: evidence, consensus and practice guidelines. Rev Nutr. 2020; 33: e200212. WeberTK Leandro-MerhiVA BernasconiI OliveiraMRM de Nutritional therapy in hospital care of in-patients with Covid-19: evidence, consensus and practice guidelines Rev Nutr 2020 33 e200212 10.1590/1678-9865202033e200212 Search in Google Scholar

Coronavirus Update (Live): 106,418,285 Cases and 2,321,908 Deaths from COVID-19 Virus Pandemic - Worldometer n.d. https://www.worldometers.info/coronavirus/ (accessed February 7, 2021). Coronavirus Update (Live) 106,418,285 Cases and 2,321,908 Deaths from COVID-19 Virus Pandemic - Worldometer n.d https://www.worldometers.info/coronavirus/ (accessed February 7, 2021). Search in Google Scholar

Calder P, Carr A, Gombart A, Eggersdorfer M. Optimal nutritional status for a well-functioning immune system is an important factor to protect against viral infections. Nutrients. 2020; 12: 1181. CalderP CarrA GombartA EggersdorferM Optimal nutritional status for a well-functioning immune system is an important factor to protect against viral infections Nutrients 2020 12 1181 10.3390/nu12041181723074932340216 Search in Google Scholar

Dixit V, Garg B, Mehta N, Pegrum J, Dhanwal D. COVID-19 infection, inception and immunity: Observations and recommendations in the light of vitamin D? J Infect Public Health. 2021: S1876034121000113. DixitV GargB MehtaN PegrumJ DhanwalD COVID-19 infection, inception and immunity: Observations and recommendations in the light of vitamin D? J Infect Public Health 2021 S1876034121000113 10.1016/j.jiph.2021.01.007781685833751982 Search in Google Scholar

Galmés S, Serra F, Palou A. Current state of evidence: Influence of nutritional and nutrigenetic factors on immunity in the COVID-19 pandemic framework. Nutrients. 2020; 12: 2738. GalmésS SerraF PalouA Current state of evidence: Influence of nutritional and nutrigenetic factors on immunity in the COVID-19 pandemic framework Nutrients 2020 12 2738 10.3390/nu12092738755169732911778 Search in Google Scholar

Quiles JL, Rivas-García L, Varela-López A, Llopis J, Battino M, Sánchez-González C. Do nutrients and other bioactive molecules from foods have anything to say in the treatment against COVID-19? Environ Res. 2020; 191: 110053. QuilesJL Rivas-GarcíaL Varela-LópezA LlopisJ BattinoM Sánchez-GonzálezC Do nutrients and other bioactive molecules from foods have anything to say in the treatment against COVID-19? Environ Res 2020 191 110053 10.1016/j.envres.2020.110053744257532835682 Search in Google Scholar

Cariou B, Hadjadj S, Wargny M, Pichelin M, Al-Salameh A, Allix I, Amadou C, Arnault G, Baudoux F, Bauduceau B, et al. Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study. Diabetologia. 2020; 63: 1500–1515. CariouB HadjadjS WargnyM PichelinM Al-SalamehA AllixI AmadouC ArnaultG BaudouxF BauduceauB Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study Diabetologia 2020 63 1500 1515 10.1007/s00125-020-05180-x725618032472191 Search in Google Scholar

Bousquet J, Anto JM, Iaccarino G, Czarlewski W, Haahtela T, Anto A, Akdis CA, Blain H, Canonica GW, Cardona V, et al. Is diet partly responsible for differences in COVID-19 death rates between and within countries? Clin Transl Allergy. 2020; 10: 16. BousquetJ AntoJM IaccarinoG CzarlewskiW HaahtelaT AntoA AkdisCA BlainH CanonicaGW CardonaV Is diet partly responsible for differences in COVID-19 death rates between and within countries? Clin Transl Allergy 2020 10 16 10.1186/s13601-020-00323-0725053432499909 Search in Google Scholar

Ceolin G, Moreira JD, Mendes BC, Schroeder J, Pietro PFD, Rieger DK. Nutritional challenges in older adults during the COVID-19 pandemic. Rev Nutr. 2020; 33: e200174. CeolinG MoreiraJD MendesBC SchroederJ PietroPFD RiegerDK Nutritional challenges in older adults during the COVID-19 pandemic Rev Nutr 2020 33 e200174 10.1590/1678-9865202032e200174 Search in Google Scholar

Wee AKH. COVID-19's toll on the elderly and those with diabetes mellitus – Is vitamin B12 deficiency an accomplice? Med Hypotheses. 2021; 146: 110374. WeeAKH COVID-19's toll on the elderly and those with diabetes mellitus – Is vitamin B12 deficiency an accomplice? Med Hypotheses 2021 146 110374 10.1016/j.mehy.2020.110374765964533257090 Search in Google Scholar

Flores-Guerrero JL, Minovic I, Groothof D, Gruppen EG, Riphagen IJ, Kootstra-Ros J, Muller Kobold A, Hak E, Navis G, Gansevoort RT, et al. Association of plasma concentration of vitamin B 12 with all-cause mortality in the general population in the Netherlands. JAMA Netw Open. 2020; 3: e1919274. Flores-GuerreroJL MinovicI GroothofD GruppenEG RiphagenIJ Kootstra-RosJ Muller KoboldA HakE NavisG GansevoortRT Association of plasma concentration of vitamin B 12 with all-cause mortality in the general population in the Netherlands JAMA Netw Open 2020 3 e1919274 10.1001/jamanetworkopen.2019.19274699126131940038 Search in Google Scholar

Dalbeni A, Bevilacqua M, Teani I, Normelli I, Mazzaferri F, Chiarioni G. Excessive Vitamin B12 and poor outcome in COVID-19 pneumonia. Nutr Metab Cardiovasc Dis. 2020: S0939475320305147. DalbeniA BevilacquaM TeaniI NormelliI MazzaferriF ChiarioniG Excessive Vitamin B12 and poor outcome in COVID-19 pneumonia Nutr Metab Cardiovasc Dis 2020 S0939475320305147 10.1016/j.numecd.2020.12.005783425933549452 Search in Google Scholar

Sviri S, Khalaila R, Daher S, Bayya A, Linton DM, Stav I, van Heerden PV. Increased vitamin B12 levels are associated with mortality in critically ill medical patients. Clin Nutr. 2012; 31: 53–59. SviriS KhalailaR DaherS BayyaA LintonDM StavI van HeerdenPV Increased vitamin B12 levels are associated with mortality in critically ill medical patients Clin Nutr 2012 31 53 59 10.1016/j.clnu.2011.08.01021899932 Search in Google Scholar

Colunga Biancatelli RML, Berrill M, Marik PE. The antiviral properties of vitamin C. Expert Rev Anti Infect Ther 2020; 18: 99–101. Colunga BiancatelliRML BerrillM MarikPE The antiviral properties of vitamin C Expert Rev Anti Infect Ther 2020 18 99 101 10.1080/14787210.2020.170648331852327 Search in Google Scholar

Alamdari DH, Moghaddam AB, Amini S, Keramati MR, Zarmehri AM, Alamdari AH, Damsaz M, Banpour H, Yarahmadi A, Kaliakos G. Application of methylene blue -vitamin C –N-acetyl cysteine for treatment of critically ill COVID-19 patients, report of a phase-I clinical trial. Eur J Pharmacol. 2020; 885: 173494. AlamdariDH MoghaddamAB AminiS KeramatiMR ZarmehriAM AlamdariAH DamsazM BanpourH YarahmadiA KaliakosG Application of methylene blue -vitamin C –N-acetyl cysteine for treatment of critically ill COVID-19 patients, report of a phase-I clinical trial Eur J Pharmacol 2020 885 173494 10.1016/j.ejphar.2020.173494744015932828741 Search in Google Scholar

Cheng RZ. Can early and high intravenous dose of vitamin C prevent and treat coronavirus disease 2019 (COVID-19)? Med Drug Discov. 2020; 5: 100028. ChengRZ Can early and high intravenous dose of vitamin C prevent and treat coronavirus disease 2019 (COVID-19)? Med Drug Discov 2020 5 100028 10.1016/j.medidd.2020.100028716749732328576 Search in Google Scholar

Holick MF. The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention. Rev Endocr Metab Disord. 2017; 18: 153–165. HolickMF The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention Rev Endocr Metab Disord 2017 18 153 165 10.1007/s11154-017-9424-1 Search in Google Scholar

Biesalski HK. Vitamin D deficiency and co-morbidities in COVID-19 patients – A fatal relationship? NFS J. 2020; 20: 10–21. BiesalskiHK Vitamin D deficiency and co-morbidities in COVID-19 patients – A fatal relationship? NFS J 2020 20 10 21 10.1016/j.nfs.2020.06.001 Search in Google Scholar

Tandon R. COVID-19 and mental health: Preserving humanity, maintaining sanity, and promoting health. Asian J Psychiatry. 2020; 51: 102256. TandonR COVID-19 and mental health: Preserving humanity, maintaining sanity, and promoting health Asian J Psychiatry 2020 51 102256 10.1016/j.ajp.2020.102256 Search in Google Scholar

Abrishami A, Dalili N, Mohammadi Torbati P, Asgari R, Arab-Ahmadi M, Behnam B, Sanei-Taheri M. Possible association of vitamin D status with lung involvement and outcome in patients with COVID-19: a retrospective study. Eur J Nutr. 2021; 60: 2249–2257. AbrishamiA DaliliN Mohammadi TorbatiP AsgariR Arab-AhmadiM BehnamB Sanei-TaheriM Possible association of vitamin D status with lung involvement and outcome in patients with COVID-19: a retrospective study Eur J Nutr 2021 60 2249 2257 10.1007/s00394-020-02411-0 Search in Google Scholar

Mehta A, Soni VK, Sharma K, Ratre YK, Shukla D, Singh AK, Vishvakarma NK. Finding Horcrux of psychiatric symptoms in COVID-19: Deficiencies of amino acids and vitamin D. Asian J Psychiatry. 2021; 55: 102523. MehtaA SoniVK SharmaK RatreYK ShuklaD SinghAK VishvakarmaNK Finding Horcrux of psychiatric symptoms in COVID-19: Deficiencies of amino acids and vitamin D Asian J Psychiatry 2021 55 102523 10.1016/j.ajp.2020.102523 Search in Google Scholar

Basheer S, Natarajan A, van Amelsvoort T, Venkataswamy MM, Ravi V, Srinath S, Grimaji SC, Christopher R. Vitamin D status of children with autism spectrum disorder: Case-control study India. Asian J Psychiatry. 2017; 30: 200–201. BasheerS NatarajanA van AmelsvoortT VenkataswamyMM RaviV SrinathS GrimajiSC ChristopherR Vitamin D status of children with autism spectrum disorder: Case-control study India Asian J Psychiatry 2017 30 200 201 10.1016/j.ajp.2017.10.031 Search in Google Scholar

Sarris J, Logan AC, Akbaraly TN, Amminger GP, Balanzá-Martínez V, Freeman MP, Hibleln J, Matsuoka Y, Mischoulon D, Mizoune T. et al. Nutritional medicine as mainstream in psychiatry. Lancet Psychiatry. 2015; 2: 71–274. SarrisJ LoganAC AkbaralyTN AmmingerGP Balanzá-MartínezV FreemanMP HiblelnJ MatsuokaY MischoulonD MizouneT Nutritional medicine as mainstream in psychiatry Lancet Psychiatry 2015 2 71 274 10.1016/S2215-0366(14)00051-0 Search in Google Scholar

Di Nicola M, Dattoli L, Moccia L, Pepe M, Janiri D, Fiorillo A, Janiri D, Fiorillo A, Janiri L, Sani G. Serum 25-hydroxyvitamin D levels and psychological distress symptoms in patients with affective disorders during the COVID-19 pandemic. Psychoneuroendocrinology. 2020; 122: 104869. Di NicolaM DattoliL MocciaL PepeM JaniriD FiorilloA JaniriD FiorilloA JaniriL SaniG Serum 25-hydroxyvitamin D levels and psychological distress symptoms in patients with affective disorders during the COVID-19 pandemic Psychoneuroendocrinology 2020 122 104869 10.1016/j.psyneuen.2020.104869748933732956989 Search in Google Scholar

Laird E, Rhodes J, Kenny RA. Vitamin D and inflammation: Potential implications for severity of Covid-19. Ir Med J. 2020; 113: 81. LairdE RhodesJ KennyRA Vitamin D and inflammation: Potential implications for severity of Covid-19 Ir Med J 2020 113 81 Search in Google Scholar

Kumar R, Rathi H, Haq A, Wimalawansa SJ, Sharma A. Putative roles of vitamin D in modulating immune response and immunopathology associated with COVID-19. Virus Res. 2021; 292: 198235. KumarR RathiH HaqA WimalawansaSJ SharmaA Putative roles of vitamin D in modulating immune response and immunopathology associated with COVID-19 Virus Res 2021 292 198235 10.1016/j.virusres.2020.198235768004733232783 Search in Google Scholar

Tehrani S., Khabiri N, Moradi H, Mosavat MS, Khabiri SS. Evaluation of vitamin D levels in COVID-19 patients referred to Labafinejad Hospital in Tehran and its relationship with disease severity and mortality. Clin Nutr ESPEN. 2021; 42: 313–317. TehraniS. KhabiriN MoradiH MosavatMS KhabiriSS Evaluation of vitamin D levels in COVID-19 patients referred to Labafinejad Hospital in Tehran and its relationship with disease severity and mortality Clin Nutr ESPEN 2021 42 313 317 10.1016/j.clnesp.2021.01.014783509733745598 Search in Google Scholar

Cereda E, Bogliolo L, Klersy C, Lobascio F, Masi S, Crotti S, De Stefano L, Bruno R, Corsico AG, Di Sabatino A. et al. Vitamin D 25OH deficiency in COVID-19 patients admitted to a tertiary referral hospital. Clin Nutr. 2020: S0261561420306014. CeredaE BoglioloL KlersyC LobascioF MasiS CrottiS De StefanoL BrunoR CorsicoAG Di SabatinoA Vitamin D 25OH deficiency in COVID-19 patients admitted to a tertiary referral hospital Clin Nutr 2020 S0261561420306014 10.1016/j.clnu.2020.10.055760585133187772 Search in Google Scholar

Angelidi AM, Belanger MJ, Lorinsky MK, Karamanis D, Chamorro-Pareja N, Ognibene J, Palaiodimos L, Mantzoros CS. Vitamin D Status is associated with in-hospital mortality and mechanical ventilation: A cohort of COVID-19 hospitalized patients. Mayo Clin Proc. 2021: S002561962100001X. AngelidiAM BelangerMJ LorinskyMK KaramanisD Chamorro-ParejaN OgnibeneJ PalaiodimosL MantzorosCS Vitamin D Status is associated with in-hospital mortality and mechanical ventilation: A cohort of COVID-19 hospitalized patients Mayo Clin Proc 2021 S002561962100001X 10.1016/j.mayocp.2021.01.001783425333714594 Search in Google Scholar

Radujkovic A, Hippchen T, Tiwari-Heckler S, Dreher S, Boxberger M, Merle U. Vitamin D deficiency and outcome of COVID-19 patients. Nutrients. 2020; 12: 2757. RadujkovicA HippchenT Tiwari-HecklerS DreherS BoxbergerM MerleU Vitamin D deficiency and outcome of COVID-19 patients Nutrients 2020 12 2757 10.3390/nu12092757755178032927735 Search in Google Scholar

Kaufman HW, Niles JK, Kroll MH, Bi C, Holick MF. SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels. PLoS One. 2020; 15: e0239252. KaufmanHW NilesJK KrollMH BiC HolickMF SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels PLoS One 2020 15 e0239252 10.1371/journal.pone.0239252749810032941512 Search in Google Scholar

Galmés S, Serra F, Palou A. Vitamin E metabolic effects and genetic variants: A challenge for precision nutrition in obesity and associated disturbances. Nutrients. 2018; 10: 1919. GalmésS SerraF PalouA Vitamin E metabolic effects and genetic variants: A challenge for precision nutrition in obesity and associated disturbances Nutrients 2018 10 1919 10.3390/nu10121919631633430518135 Search in Google Scholar

Keflie TS, Biesalski HK. Micronutrients and bioactive substances: Their potential roles in combating COVID-19. Nutrition. 2021; 84: 111103. KeflieTS BiesalskiHK Micronutrients and bioactive substances: Their potential roles in combating COVID-19 Nutrition 2021 84 111103 10.1016/j.nut.2020.111103771787933450678 Search in Google Scholar

Janssen R, Visser MPJ, Dofferhoff ASM, Vermeer C, Janssens W, Walk J. Vitamin K metabolism as the potential missing link between lung damage and thromboembolism in coronavirus disease 2019. Br J Nutr. 2021; 126: 191–198. JanssenR VisserMPJ DofferhoffASM VermeerC JanssensW WalkJ Vitamin K metabolism as the potential missing link between lung damage and thromboembolism in coronavirus disease 2019 Br J Nutr 2021 126 191 198 10.1017/S0007114520003979757863533023681 Search in Google Scholar

Dofferhoff ASM, Piscaer I, Schurgers LJ, Visser MPJ, van den Ouweland JMW, de Jong PA, Gosens R, Hackeng TM, van Daal H, Lux P. et al. Reduced Vitamin K status as a potentially modifiable risk factor of severe coronavirus disease. 2019. Clin Infect Dis. 2021: 73: e4039–e4046. DofferhoffASM PiscaerI SchurgersLJ VisserMPJ van den OuwelandJMW de JongPA GosensR HackengTM van DaalH LuxP Reduced Vitamin K status as a potentially modifiable risk factor of severe coronavirus disease 2019 Clin Infect Dis 2021 73 e4039 e4046 10.1093/cid/ciaa1258749954632852539 Search in Google Scholar

Speed V, Patel RK, Byrne R, Roberts LN, Arya R. A perfect storm: Root cause analysis of supra-therapeutic anticoagulation with vitamin K antagonists during the COVID-19 pandemic. Thromb Res. 2020; 192: 73–74. SpeedV PatelRK ByrneR RobertsLN AryaR A perfect storm: Root cause analysis of supra-therapeutic anticoagulation with vitamin K antagonists during the COVID-19 pandemic Thromb Res 2020 192 73 74 10.1016/j.thromres.2020.05.024722997132425265 Search in Google Scholar

Chen N, Zhao C, Zhang T. Selenium transformation and selenium-rich foods. Food Biosci. 2021: 100875. ChenN ZhaoC ZhangT Selenium transformation and selenium-rich foods Food Biosci 2021 100875 10.1016/j.fbio.2020.100875 Search in Google Scholar

Guillin O, Vindry C, Ohlmann T, Chavatte L. Selenium, selenoproteins and viral infection. Nutrients. 2019; 11: 2101. GuillinO VindryC OhlmannT ChavatteL Selenium, selenoproteins and viral infection Nutrients 2019 11 2101 10.3390/nu11092101676959031487871 Search in Google Scholar

Harthill M. Review: Micronutrient selenium deficiency influences evolution of some viral infectious diseases. Biol Trace Elem Res. 2011; 143: 1325–1336. HarthillM Review: Micronutrient selenium deficiency influences evolution of some viral infectious diseases Biol Trace Elem Res 2011 143 1325 1336 10.1007/s12011-011-8977-1709049021318622 Search in Google Scholar

Pock HL. A cohort study to evaluate the effect of combination Vitamin D, magnesium and vitamin B12 (DMB) on progression to severe outcome in older COVID-19 patients. PockHL A cohort study to evaluate the effect of combination Vitamin D, magnesium and vitamin B12 (DMB) on progression to severe outcome in older COVID-19 patients Search in Google Scholar

Akatsu H. Exploring the effect of probiotics, prebiotics, and postbiotics in strengthening immune activity in the elderly. Vaccines. 2021; 9: 136. AkatsuH Exploring the effect of probiotics, prebiotics, and postbiotics in strengthening immune activity in the elderly Vaccines 2021 9 136 10.3390/vaccines9020136791532933567790 Search in Google Scholar

Sundararaman A, Ray M, Ravindra PV, Halami PM. Role of probiotics to combat viral infections with emphasis on COVID-19. Appl Microbiol Biotechnol. 2020; 104: 8089–8104. SundararamanA RayM RavindraPV HalamiPM Role of probiotics to combat viral infections with emphasis on COVID-19 Appl Microbiol Biotechnol 2020 104 8089 8104 10.1007/s00253-020-10832-4743485232813065 Search in Google Scholar

Dai H, Han J, Lichtfouse E. Smarter cures to combat COVID-19 and future pathogens: A review. Environ Chem Lett. 2021; 19: 2759–2771. DaiH HanJ LichtfouseE Smarter cures to combat COVID-19 and future pathogens: A review Environ Chem Lett 2021 19 2759 2771 10.1007/s10311-021-01224-9801751333824633 Search in Google Scholar

Singla V, Chakkaravarthi S. Applications of prebiotics in food industry: A review. Food Sci Technol Int. 2017; 23: 649–667. SinglaV ChakkaravarthiS Applications of prebiotics in food industry: A review Food Sci Technol Int 2017 23 649 667 10.1177/108201321772176928762780 Search in Google Scholar

Al-Ansari MM, Sahlah SA, AlHumaid L, Ranjit Singh AJ. Probiotic lactobacilli: Can be a remediating supplement for pandemic COVID-19. A review. J King Saud Univ – Sci. 2021; 33: 101286. Al-AnsariMM SahlahSA AlHumaidL Ranjit SinghAJ Probiotic lactobacilli: Can be a remediating supplement for pandemic COVID-19. A review J King Saud Univ – Sci 2021 33 101286 10.1016/j.jksus.2020.101286783696433519144 Search in Google Scholar

La Fata G, Weber P, Mohajeri MH. Probiotics and the gut immune system: indirect regulation. Probiotics Antimicrob Proteins. 2018; 10: 11–21. La FataG WeberP MohajeriMH Probiotics and the gut immune system: indirect regulation Probiotics Antimicrob Proteins 2018 10 11 21 10.1007/s12602-017-9322-6580139728861741 Search in Google Scholar

Baud D, Dimopoulou Agri V, Gibson GR, Reid G, Giannoni E. Using probiotics to flatten the curve of coronavirus disease COVID-2019 pandemic. Front Public Health. 2020; 8: 186. BaudD Dimopoulou AgriV GibsonGR ReidG GiannoniE Using probiotics to flatten the curve of coronavirus disease COVID-2019 pandemic Front Public Health 2020 8 186 10.3389/fpubh.2020.00186722739732574290 Search in Google Scholar

Morais AHA, Passos TS, Maciel BLL, da Silva-Maia JK. Can probiotics and diet promote beneficial immune modulation and purine control in coronavirus infection? Nutrients. 2020; 12: 1737. MoraisAHA PassosTS MacielBLL da Silva-MaiaJK Can probiotics and diet promote beneficial immune modulation and purine control in coronavirus infection? Nutrients 2020 12 1737 10.3390/nu12061737735264332532069 Search in Google Scholar

Nakayama Y, Moriya T, Sakai F, Ikeda N, Shiozaki T, Hosoya T, Nakagawa H, Miyazaki T. Oral administration of Lactobacillus gasseri SBT2055 is effective for preventing influenza in mice. Sci Rep. 2015; 4: 4638. NakayamaY MoriyaT SakaiF IkedaN ShiozakiT HosoyaT NakagawaH MiyazakiT Oral administration of Lactobacillus gasseri SBT2055 is effective for preventing influenza in mice Sci Rep 2015 4 4638 10.1038/srep04638 Search in Google Scholar

Eguchi K, Fujitani N, Nakagawa H, Miyazaki T. Prevention of respiratory syncytial virus infection with probiotic lactic acid bacterium Lactobacillus gasseri SBT2055. Sci Rep. 2019; 9: 4812. EguchiK FujitaniN NakagawaH MiyazakiT Prevention of respiratory syncytial virus infection with probiotic lactic acid bacterium Lactobacillus gasseri SBT2055 Sci Rep 2019 9 4812 10.1038/s41598-019-39602-7 Search in Google Scholar

Tiwari SK, Dicks LMT, Popov IV, Karaseva A, Ermakov AM, Suvorov A, Tagg JR, Weeks R, Chikindas ML. Probiotics at War Against Viruses: What is missing from the picture? Front Microbiol. 2020; 11: 1877. TiwariSK DicksLMT PopovIV KarasevaA ErmakovAM SuvorovA TaggJR WeeksR ChikindasML Probiotics at War Against Viruses: What is missing from the picture? Front Microbiol 2020 11 1877 10.3389/fmicb.2020.01877 Search in Google Scholar

Mak JWY, Chan FKL, Ng SC. Probiotics and COVID-19: One size does not fit all. Lancet Gastroenterol Hepatol. 2020; 5: 644–645. MakJWY ChanFKL NgSC Probiotics and COVID-19: One size does not fit all Lancet Gastroenterol Hepatol 2020 5 644 645 10.1016/S2468-1253(20)30122-9 Search in Google Scholar

Mohseni H, Amini S, Abiri B, Kalantar M, Kaydani M, Barati B, Pirabbasi E, Bahrami F. Are history of dietary intake and food habits of patients with clinical symptoms of COVID 19 different from healthy controls? A case–control study. Clin Nutr ESPEN. 2021: S2405457721000358. MohseniH AminiS AbiriB KalantarM KaydaniM BaratiB PirabbasiE BahramiF Are history of dietary intake and food habits of patients with clinical symptoms of COVID 19 different from healthy controls? A case–control study Clin Nutr ESPEN 2021 S2405457721000358 10.1016/j.clnesp.2021.01.021784621833745593 Search in Google Scholar

Venema K. Foreword – The importance of a healthy microbiota in the era of COVID-19: A year after the COVID-19 pandemic. Benef Microbes. 2021; 12: 1–3. VenemaK Foreword – The importance of a healthy microbiota in the era of COVID-19: A year after the COVID-19 pandemic Benef Microbes 2021 12 1 3 10.3920/BM2021.x00133627060 Search in Google Scholar

Kwak JH, Seo JM, Kim NH, Arasu MV, Kim S, Yoon MK, Kim SJ. Variation of quercetin glycoside derivatives in three onion (Allium cepa L.) varieties. Saudi J Biol Sci. 2017; 24: 1387–1391. KwakJH SeoJM KimNH ArasuMV KimS YoonMK KimSJ Variation of quercetin glycoside derivatives in three onion (Allium cepa L.) varieties Saudi J Biol Sci 2017 24 1387 1391 10.1016/j.sjbs.2016.05.014556246228855836 Search in Google Scholar

Dorsch W, Ring J. Anti-inflammatory substances from onions could be an option for treatment of COVID-19 - a hypothesis. Allergo J Int. 2020; 29: 284–285. DorschW RingJ Anti-inflammatory substances from onions could be an option for treatment of COVID-19 - a hypothesis Allergo J Int 2020 29 284 285 10.1007/s40629-020-00146-2757324333101838 Search in Google Scholar

Dorsch W, Ring J. Anti-inflammatory substances from onions could be an option for treatment of COVID-19: A hypothesis. Allergo J. 2020; 29: 30–31. DorschW RingJ Anti-inflammatory substances from onions could be an option for treatment of COVID-19: A hypothesis Allergo J 2020 29 30 31 10.1007/s15007-020-2644-9773518433343096 Search in Google Scholar

Neha Sharma. Efficacy of garlic and onion against virus. Int J Res Pharm Sci. 2019; 10: 3578–3586. NehaSharma Efficacy of garlic and onion against virus Int J Res Pharm Sci 2019 10 3578 3586 10.26452/ijrps.v10i4.1738 Search in Google Scholar

Harazem R, Rahman S, Kenawy A. Evaluation of antiviral activity of Allium cepa and Allium sativum extracts against Newcastle disease virus. Alex J Vet Sci. 2019; 61: 108. HarazemR RahmanS KenawyA Evaluation of antiviral activity of Allium cepa and Allium sativum extracts against Newcastle disease virus Alex J Vet Sci 2019 61 108 10.5455/ajvs.29663 Search in Google Scholar

Chakraborty D. Garlic (Lahsun) – An Immunity Booster against 2020:3. ChakrabortyD Garlic (Lahsun) – An Immunity Booster against 2020 3 Search in Google Scholar

Donma MM, Donma O. The effects of allium sativum on immunity within the scope of COVID-19 infection. Med Hypotheses. 2020; 144: 109934. DonmaMM DonmaO The effects of allium sativum on immunity within the scope of COVID-19 infection Med Hypotheses 2020 144 109934 10.1016/j.mehy.2020.109934726582532512493 Search in Google Scholar

Khubber S, Hashemifesharaki R, Mohammadi M, Gharibzahedi SMT. Garlic (Allium sativum L.): A potential unique therapeutic food rich in organosulfur and flavonoid compounds to fight with COVID-19. Nutr J. 2020; 19: 124. KhubberS HashemifesharakiR MohammadiM GharibzahediSMT Garlic (Allium sativum L.): A potential unique therapeutic food rich in organosulfur and flavonoid compounds to fight with COVID-19 Nutr J 2020 19 124 10.1186/s12937-020-00643-8767307233208167 Search in Google Scholar

Thuy BTP, My TTA, Hai NTT, Hieu LT, Hoa TT, Loan HTP, Triet NT, Anh TTV, Quy PT, Tat PV, et al. Investigation into SARS-CoV-2 resistance of compounds in garlic essential oil. ACS Omega. 2020; 5: 8312–8320. ThuyBTP MyTTA HaiNTT HieuLT HoaTT LoanHTP TrietNT AnhTTV QuyPT TatPV Investigation into SARS-CoV-2 resistance of compounds in garlic essential oil ACS Omega 2020 5 8312 8320 10.1021/acsomega.0c00772712390732363255 Search in Google Scholar

Batiha GE-S, Beshbishy AM, Ikram M, Mulla ZS, El-Hack MEA, Taha AE, Algammal AM, Ali Elewa YH. The pharmacological activity, biochemical properties, and pharmacokinetics of the major natural polyphenolic flavonoid: Quercetin. Foods. 2020; 9: 374. BatihaGE-S BeshbishyAM IkramM MullaZS El-HackMEA TahaAE AlgammalAM Ali ElewaYH The pharmacological activity, biochemical properties, and pharmacokinetics of the major natural polyphenolic flavonoid: Quercetin Foods 2020 9 374 10.3390/foods9030374714393132210182 Search in Google Scholar

Zandi K, Teoh BT, Sam SS, Wong PF, Mustafa M, AbuBakar S. Antiviral activity of four types of bioflavonoid against dengue virus type-2. Virol J. 2011; 8: 560. ZandiK TeohBT SamSS WongPF MustafaM AbuBakarS Antiviral activity of four types of bioflavonoid against dengue virus type-2 Virol J 2011 8 560 10.1186/1743-422X-8-560327199822201648 Search in Google Scholar

Chiang LC. In vitro antiviral activities of Caesalpinia pulcherrima and its related flavonoids. J Antimicrob Chemother. 2003; 52: 194–198. ChiangLC In vitro antiviral activities of Caesalpinia pulcherrima and its related flavonoids J Antimicrob Chemother 2003 52 194 198 10.1093/jac/dkg29112837746 Search in Google Scholar

Kumar S, Pandey AK. Chemistry and biological activities of flavonoids: An overview. Sci World J. 2013; 2013: 162750. KumarS PandeyAK Chemistry and biological activities of flavonoids: An overview Sci World J 2013 2013 162750 10.1155/2013/162750389154324470791 Search in Google Scholar

Derosa G, Maffioli P, D’Angelo A, Di Pierro F. A role for quercetin in coronavirus disease 2019 (COVID-19). Phytother Res. 2021; 35: 1230–1236. DerosaG MaffioliP D’AngeloA Di PierroF A role for quercetin in coronavirus disease 2019 (COVID-19) Phytother Res 2021 35 1230 1236 10.1002/ptr.6887767568533034398 Search in Google Scholar

Aucoin M, Cooley K, Saunders PR, Cardozo V, Remy D, Cramer H, Abad CN, Hannan N. The effect of quercetin on the prevention or treatment of COVID-19 and other respiratory tract infections in humans: A rapid review. Adv Integr Med. 2020; 7: 247–251. AucoinM CooleyK SaundersPR CardozoV RemyD CramerH AbadCN HannanN The effect of quercetin on the prevention or treatment of COVID-19 and other respiratory tract infections in humans: A rapid review Adv Integr Med 2020 7 247 251 10.1016/j.aimed.2020.07.007739210732837891 Search in Google Scholar

Horne JR, Vohl M-C. Biological plausibility for interactions between dietary fat, resveratrol, ACE2, and SARS-CoV illness severity. Am J Physiol-Endocrinol Metab. 2020; 318: E830–E833. HorneJR VohlM-C Biological plausibility for interactions between dietary fat, resveratrol, ACE2, and SARS-CoV illness severity Am J Physiol-Endocrinol Metab 2020 318 E830 E833 10.1152/ajpendo.00150.2020721509132310688 Search in Google Scholar

Wahedi HM, Ahmad S, Abbasi SW. Stilbene-based natural compounds as promising drug candidates against COVID-19. J Biomol Struct Dyn. 2021; 39: 3225–3234. WahediHM AhmadS AbbasiSW Stilbene-based natural compounds as promising drug candidates against COVID-19 J Biomol Struct Dyn 2021 39 3225 3234 10.1080/07391102.2020.176274332345140 Search in Google Scholar

Lin SC, Ho CT, Chuo WH, Li S, Wang TT, Lin CC. Effective inhibition of MERS-CoV infection by resveratrol. BMC Infect Dis. 2017; 17: 144. LinSC HoCT ChuoWH LiS WangTT LinCC Effective inhibition of MERS-CoV infection by resveratrol BMC Infect Dis 2017 17 144 10.1186/s12879-017-2253-8530778028193191 Search in Google Scholar

Zhao X, Xu J, Song X, Jia R, Yin Z, Cheng A, Jia R, Zou Y, Li L, Yin L, et al. Antiviral effect of resveratrol in ducklings infected with virulent duck enteritis virus. Antiviral Res. 2016; 130: 93–100. ZhaoX XuJ SongX JiaR YinZ ChengA JiaR ZouY LiL YinL Antiviral effect of resveratrol in ducklings infected with virulent duck enteritis virus Antiviral Res 2016 130 93 100 10.1016/j.antiviral.2016.03.01427040314 Search in Google Scholar

Zhao X, Tong W, Song X, Jia R, Li L, Zou Y, He C, Liang X, Lv C, Jing B, et al. Antiviral Effect of resveratrol in piglets infected with virulent pseudorabies virus. Viruses. 2018; 10: 457. ZhaoX TongW SongX JiaR LiL ZouY HeC LiangX LvC JingB Antiviral Effect of resveratrol in piglets infected with virulent pseudorabies virus Viruses 2018 10 457 10.3390/v10090457616407830150559 Search in Google Scholar

Marinella MA. Indomethacin and resveratrol as potential treatment adjuncts for SARS-CoV-2/COVID-19. Int J Clin Pract. 2020; 74: e13535. MarinellaMA Indomethacin and resveratrol as potential treatment adjuncts for SARS-CoV-2/COVID-19 Int J Clin Pract 2020 74 e13535 10.1111/ijcp.13535726199532412158 Search in Google Scholar

Giordo R, Zinellu A, Eid AH, Pintus G. Therapeutic potential of resveratrol in COVID-19-associated hemostatic disorders. Molecules. 2021: 26: 856. GiordoR ZinelluA EidAH PintusG Therapeutic potential of resveratrol in COVID-19-associated hemostatic disorders Molecules 2021 26 856 10.3390/molecules26040856791570033562030 Search in Google Scholar

Mittra I, de Souza R, Bhadade R, Madke T, Shankpal PD, Joshi M. Resveratrol and copper for treatment of severe COVID-19: an observational study (RESCU 002). Infectious Diseases (except HIV/AIDS). 2020. MittraI de SouzaR BhadadeR MadkeT ShankpalPD JoshiM Resveratrol and copper for treatment of severe COVID-19: an observational study (RESCU 002) Infectious Diseases (except HIV/AIDS) 2020 10.1101/2020.07.21.20151423 Search in Google Scholar

Mounce BC, Cesaro T, Carrau L, Vallet T, Vignuzzi M. Curcumin inhibits Zika and chikungunya virus infection by inhibiting cell binding. Anti-viral Res. 2017; 142: 148–157. MounceBC CesaroT CarrauL ValletT VignuzziM Curcumin inhibits Zika and chikungunya virus infection by inhibiting cell binding Anti-viral Res 2017 142 148 157 10.1016/j.antiviral.2017.03.01428343845 Search in Google Scholar

Kim K, Kim KH, Kim HY, Cho HK, Sakamoto N, Cheong J. Curcumin inhibits hepatitis C virus replication via suppressing the Akt-SREBP-1 pathway. FEBS Lett. 2010; 584: 707–712. KimK KimKH KimHY ChoHK SakamotoN CheongJ Curcumin inhibits hepatitis C virus replication via suppressing the Akt-SREBP-1 pathway FEBS Lett 2010 584 707 712 10.1016/j.febslet.2009.12.01920026048 Search in Google Scholar

Mazumder A, Raghavan K, Weinstein J, Kohn KW, Pommier Y. Inhibition of human immunodeficiency virus type-1 integrase by curcumin. Biochem Pharmacol. 1995; 49: 1165–1170. MazumderA RaghavanK WeinsteinJ KohnKW PommierY Inhibition of human immunodeficiency virus type-1 integrase by curcumin Biochem Pharmacol 1995 49 1165 1170 10.1016/0006-2952(95)98514-A Search in Google Scholar

Padilla-S L, Rodríguez A, Gonzales MM, Gallego-G JC, Castaño-O JC. Inhibitory effects of curcumin on dengue virus type 2-infected cells in vitro. Arch Virol. 2014; 159: 573–579. Padilla-SL RodríguezA GonzalesMM Gallego-GJC Castaño-OJC Inhibitory effects of curcumin on dengue virus type 2-infected cells in vitro Arch Virol 2014 159 573 579 10.1007/s00705-013-1849-6 Search in Google Scholar

Kutluay SB, Doroghazi J, Roemer ME, Triezenberg SJ. Curcumin inhibits herpes simplex virus immediate-early gene expression by a mechanism independent of p300/CBP histone acetyltransferase activity. Virology. 2008; 373: 239–247. KutluaySB DoroghaziJ RoemerME TriezenbergSJ Curcumin inhibits herpes simplex virus immediate-early gene expression by a mechanism independent of p300/CBP histone acetyltransferase activity Virology 2008 373 239 247 10.1016/j.virol.2007.11.028 Search in Google Scholar

Anggakusuma, Colpitts CC, Schang LM, Rachmawati H, Frentzen A, Pfaender S, Behrendt P, Brown RJP, Bankwitz D, Steinmann J, et al. Turmeric curcumin inhibits entry of all hepatitis C virus genotypes into human liver cells. Gut. 2014; 63: 1137–1149. Anggakusuma ColpittsCC SchangLM RachmawatiH FrentzenA PfaenderS BehrendtP BrownRJP BankwitzD SteinmannJ Turmeric curcumin inhibits entry of all hepatitis C virus genotypes into human liver cells Gut 2014 63 1137 1149 10.1136/gutjnl-2012-304299 Search in Google Scholar

Celik C, Gencay A, Ocsoy I. Can food and food supplements be deployed in the fight against the COVID 19 pandemic? Biochim Biophys Acta - Gen Subj. 2021; 1865: 129801. CelikC GencayA OcsoyI Can food and food supplements be deployed in the fight against the COVID 19 pandemic? Biochim Biophys Acta - Gen Subj 2021 1865 129801 10.1016/j.bbagen.2020.129801 Search in Google Scholar

Roy A, Sarkar B, Celik C, Ghosh A, Basu U, Jana M, Arundhati J, Ayse G, Gulten CS, Ildiz N, et al. Can concomitant use of zinc and curcumin with other immunity - boosting nutraceuticals be the arsenal against COVID - 19? Phytother Res. 2020; 34: 2425–2428. RoyA SarkarB CelikC GhoshA BasuU JanaM ArundhatiJ AyseG GultenCS IldizN Can concomitant use of zinc and curcumin with other immunity - boosting nutraceuticals be the arsenal against COVID - 19? Phytother Res 2020 34 2425 2428 10.1002/ptr.6766 Search in Google Scholar

Roblin X, Pofelski J, Zarski JP. Rôle de l’homocystéine au cours de la stéatose hépatique et de l’hépatite chronique C. Gastroentérologie Clin Biol. 2007; 31: 415–420. RoblinX PofelskiJ ZarskiJP Rôle de l’homocystéine au cours de la stéatose hépatique et de l’hépatite chronique C Gastroentérologie Clin Biol 2007 31 415 420 10.1016/S0399-8320(07)89402-4 Search in Google Scholar

Djuric D, Jakovljevic V, Zivkovic V, Srejovic I. Homocysteine and homocysteine-related compounds: An overview of the roles in the pathology of the cardiovascular and nervous systems. Can J Physiol Pharmacol. 2018; 96: 991–1003. DjuricD JakovljevicV ZivkovicV SrejovicI Homocysteine and homocysteine-related compounds: An overview of the roles in the pathology of the cardiovascular and nervous systems Can J Physiol Pharmacol 2018 96 991 1003 10.1139/cjpp-2018-011230130426 Search in Google Scholar

Abike F, Engin AB, Dunder İ, Tapisiz OL, Aslan C, Kutluay L. Human papilloma virus persistence and neopterin, folate and homocysteine levels in cervical dysplasias. Arch Gynecol Obstet. 2011; 284: 209–214. AbikeF EnginAB Dunderİ TapisizOL AslanC KutluayL Human papilloma virus persistence and neopterin, folate and homocysteine levels in cervical dysplasias Arch Gynecol Obstet 2011 284 209 214 10.1007/s00404-010-1650-720740364 Search in Google Scholar

Deminice R. Elevated homocysteine levels in human immunodeficiency virus-infected patients under antiretroviral therapy: A meta-analysis. World J Virol. 2015; 4: 147. DeminiceR Elevated homocysteine levels in human immunodeficiency virus-infected patients under antiretroviral therapy: A meta-analysis World J Virol 2015 4 147 10.5501/wjv.v4.i2.147441911925964880 Search in Google Scholar

Ibrahimagić OĆ, Smajlović D, Dostović Z, Vidović M, Tupković E, Kunić S. Comment on an article: “Homocysteine as a potential predictor of cardiovascular risk in patients with COVID-19“. Med Hypotheses. 2020; 143: 110107. Ibrahimagić SmajlovićD DostovićZ VidovićM TupkovićE KunićS Comment on an article: “Homocysteine as a potential predictor of cardiovascular risk in patients with COVID-19“ Med Hypotheses 2020 143 110107 10.1016/j.mehy.2020.110107736103732721803 Search in Google Scholar

Ponti G, Ruini C, Tomasi A. Homocysteine as a potential predictor of cardiovascular risk in patients with COVID-19. Med Hypotheses. 2020; 143: 109859. PontiG RuiniC TomasiA Homocysteine as a potential predictor of cardiovascular risk in patients with COVID-19 Med Hypotheses 2020 143 109859 10.1016/j.mehy.2020.109859724025232464494 Search in Google Scholar

Berretta AA, Silveira MAD, Cóndor Capcha JM, De Jong D. Propolis and its potential against SARS-CoV-2 infection mechanisms and COVID-19 disease. Biomed Pharmacother. 2020; 131: 110622. BerrettaAA SilveiraMAD Cóndor CapchaJM De JongD Propolis and its potential against SARS-CoV-2 infection mechanisms and COVID-19 disease Biomed Pharmacother 2020 131 110622 10.1016/j.biopha.2020.110622743029132890967 Search in Google Scholar

Ashry ESHE, Ahmad TA. The use of propolis as vaccine's adjuvant. Vaccine. 2012; 31: 31–39. AshryESHE AhmadTA The use of propolis as vaccine's adjuvant Vaccine 2012 31 31 39 10.1016/j.vaccine.2012.10.09523137844 Search in Google Scholar

Amoros M, Simõs CMO, Girre L, Sauvager F, Cormier M. Synergistic effect of flavones and flavonols against herpes simplex virus type 1 in cell culture. Comparison with the antiviral activity of propolis. J Nat Prod. 1992; 55: 1732–1740. AmorosM SimõsCMO GirreL SauvagerF CormierM Synergistic effect of flavones and flavonols against herpes simplex virus type 1 in cell culture. Comparison with the antiviral activity of propolis J Nat Prod 1992 55 1732 1740 10.1021/np50090a0031338212 Search in Google Scholar

Cohen HA, Varsano I, Kahan E, Sarrell EM, Uziel Y. Effectiveness of an herbal preparation containing Echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: A randomized, double-blind, placebo-controlled, multicenter study. Arch Pediatr Adolesc Med. 2004; 158: 217. CohenHA VarsanoI KahanE SarrellEM UzielY Effectiveness of an herbal preparation containing Echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: A randomized, double-blind, placebo-controlled, multicenter study Arch Pediatr Adolesc Med 2004 158 217 10.1001/archpedi.158.3.21714993078 Search in Google Scholar

Serkedjieva J, Manolova N, Bankova V. Anti-influenza virus effect of some propolis constituents and their analogues (esters of substituted cinnamic acids). J Nat Prod. 1992; 55: 294–297. SerkedjievaJ ManolovaN BankovaV Anti-influenza virus effect of some propolis constituents and their analogues (esters of substituted cinnamic acids) J Nat Prod 1992 55 294 297 10.1021/np50081a0031593279 Search in Google Scholar

Mhatre S, Srivastava T, Naik S, Patravale V. Antiviral activity of green tea and black tea polyphenols in prophylaxis and treatment of COVID-19: A review. Phytomedicine. 2021: 85: 153286. MhatreS SrivastavaT NaikS PatravaleV Antiviral activity of green tea and black tea polyphenols in prophylaxis and treatment of COVID-19: A review Phytomedicine 2021 85 153286 10.1016/j.phymed.2020.153286736700432741697 Search in Google Scholar

Chacko SM, Thambi PT, Kuttan R, Nishigaki I. Beneficial effects of green tea: A literature review. Chin Med. 2010; 5: 13. ChackoSM ThambiPT KuttanR NishigakiI Beneficial effects of green tea: A literature review Chin Med 2010 5 13 10.1186/1749-8546-5-13285561420370896 Search in Google Scholar

Catherine DeSoto M. Regional differences in use of immune-modulating catechins should be investigated regarding COVID-19. Brain Behav Immun. 2020; 89: 526–527. Catherine DeSotoM Regional differences in use of immune-modulating catechins should be investigated regarding COVID-19 Brain Behav Immun 2020 89 526 527 10.1016/j.bbi.2020.07.012736285332679175 Search in Google Scholar

Bishop E, Ismailova A, Dimeloe S, Hewison M, White JH. Vitamin D and immune regulation: Antibacterial, antiviral, anti-inflammatory. JBMR Plus. 2020; 5: e10405. BishopE IsmailovaA DimeloeS HewisonM WhiteJH Vitamin D and immune regulation: Antibacterial, antiviral, anti-inflammatory JBMR Plus 2020 5 e10405 10.1002/jbm4.10405746127932904944 Search in Google Scholar

Pontes-Quero GM, Benito-Garzón L, Pérez Cano J, Aguilar MR, Vázquez-Lasa B. Amphiphilic polymeric nanoparticles encapsulating curcumin: Antioxidant, anti-inflammatory and biocompatibility studies. Mater Sci Eng C. 2021; 121: 111793. Pontes-QueroGM Benito-GarzónL Pérez CanoJ AguilarMR Vázquez-LasaB Amphiphilic polymeric nanoparticles encapsulating curcumin: Antioxidant, anti-inflammatory and biocompatibility studies Mater Sci Eng C 2021 121 111793 10.1016/j.msec.2020.11179333579443 Search in Google Scholar

Tian C, Liu X, Chang Y, Wang R, Lv T, Cui C. Investigation of the anti-inflammatory and antioxidant activities of luteolin, kaempferol, apigenin and quercetin. South Afr J Bot. 2021; 137: 257–264. TianC LiuX ChangY WangR LvT CuiC Investigation of the anti-inflammatory and antioxidant activities of luteolin, kaempferol, apigenin and quercetin South Afr J Bot 2021 137 257 264 10.1016/j.sajb.2020.10.022 Search in Google Scholar

Patterson T, Isales CM, Fulzele S. Low level of vitamin C and dysregulation of vitamin C transporter might be involved in the severity of COVID-19 Infection. Aging Dis. 2021; 12: 14. PattersonT IsalesCM FulzeleS Low level of vitamin C and dysregulation of vitamin C transporter might be involved in the severity of COVID-19 Infection Aging Dis 2021 12 14 10.14336/AD.2020.0918780127233532123 Search in Google Scholar

Das S, Majumder B, Biswas AK. Selenium alleviates arsenic induced stress by modulating growth, oxidative stress, antioxidant defense and thiol metabolism in rice seedlings. Int J Phytoremediation. 2021:1–15. DasS MajumderB BiswasAK Selenium alleviates arsenic induced stress by modulating growth, oxidative stress, antioxidant defense and thiol metabolism in rice seedlings Int J Phytoremediation 2021 1 15 10.1080/15226514.2021.197563934579603 Search in Google Scholar

Manjunath SH, Thimmulappa RK. Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19. J Pharm Anal. 2021: S2095177921001106. ManjunathSH ThimmulappaRK Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19 J Pharm Anal 2021 S2095177921001106 10.1016/j.jpha.2021.09.009845023134567823 Search in Google Scholar

Teafatiller T, Agrawal S, De Robles G, Rahmatpanah F, Subramanian VS, Agrawal A. Vitamin C enhances antiviral functions of lung epithelial cells. Biomolecules. 2021; 11: 1148. TeafatillerT AgrawalS De RoblesG RahmatpanahF SubramanianVS AgrawalA Vitamin C enhances antiviral functions of lung epithelial cells Biomolecules 2021 11 1148 10.3390/biom11081148839497934439814 Search in Google Scholar

ter Ellen BM, Kumar ND, Bouma EM, Troost B, van de Pol DPI, van der Ende-Metselaar HH, Apperloo L, van Gosliga D, van den Berge M, Nawijn MC. et al. Resveratrol and pterostilbene potently inhibit SARS-CoV-2 replication in vitro. Microbiology. 2020. ter EllenBM KumarND BoumaEM TroostB van de PolDPI van der Ende-MetselaarHH ApperlooL van GosligaD van den BergeM NawijnMC Resveratrol and pterostilbene potently inhibit SARS-CoV-2 replication in vitro Microbiology 2020 10.1101/2020.09.24.285940 Search in Google Scholar

Marreiro D do N, Cruz KJC, Oliveira ARS de, Morais JBS, Freitas B de J e S de A, Melo SR de S, de Sousa Melo SR, Dos Santos LR. et al. Antiviral and immunological activity of zinc and possible role in COVID-19. Br J Nutr. 2021: 1–8. MarreiroD do N CruzKJC OliveiraARS de MoraisJBS FreitasB de J e S de A MeloSR de S de Sousa MeloSR Dos SantosLR Antiviral and immunological activity of zinc and possible role in COVID-19 Br J Nutr 2021 1 8 10.1017/S0007114521002099843850934128459 Search in Google Scholar

WHO EMRO | Nutrition advice for adults during the COVID-19 outbreak | Nutrition-infocus | Nutrition http://www.emro.who.int/nutrition/nutrition-infocus/nutrition-advice-for-adults-during-the-covid-19-outbreak.html (accessed February 10, 2021). WHO EMRO | Nutrition advice for adults during the COVID-19 outbreak | Nutrition-infocus | Nutrition http://www.emro.who.int/nutrition/nutrition-infocus/nutrition-advice-for-adults-during-the-covid-19-outbreak.html (accessed February 10, 2021). Search in Google Scholar

ASPEN | Nutrition and Hydration: Quick Facts for COVID-19 Patients https://www.nutritioncare.org/Guidelines_and_Clinical_Resources/Resources_for_Clinicians_Caring_for_Patients_with_Coronavirus/ (accessed February 10, 2021). ASPEN | Nutrition and Hydration: Quick Facts for COVID-19 Patients https://www.nutritioncare.org/Guidelines_and_Clinical_Resources/Resources_for_Clinicians_Caring_for_Patients_with_Coronavirus/ (accessed February 10, 2021). Search in Google Scholar

Martindale R, Patel JJ, Taylor B, Arabi YM, Warren M, McClave SA. Nutrition therapy in critically ill patients with coronavirus disease 2019. J Parenter Enteral Nutr. 2020: 44: 1174–1184. MartindaleR PatelJJ TaylorB ArabiYM WarrenM McClaveSA Nutrition therapy in critically ill patients with coronavirus disease 2019 J Parenter Enteral Nutr 2020 44 1174 1184 10.1002/jpen.1930728371332462719 Search in Google Scholar

Barazzoni R, Bischoff SC, Breda J, Wickramasinghe K, Krznaric Z, Nitzan D, Pirlich M, Singer Pet al. ESPEN expert statements and practical guidance for nutritional management of individuals with SARS-CoV-2 infection. Clin Nutr. 2020; 39: 1631–1638. BarazzoniR BischoffSC BredaJ WickramasingheK KrznaricZ NitzanD PirlichM SingerP ESPEN expert statements and practical guidance for nutritional management of individuals with SARS-CoV-2 infection Clin Nutr 2020 39 1631 1638 10.1016/j.clnu.2020.03.022713814932305181 Search in Google Scholar

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