Table 2.
Dietary supplements against COVID-19.
| Dietary supplements | Biological sources | Active constituents |
|---|---|---|
| Echinacea (NCT04981314) | Group of purple coneflower obtained from the genus Echinacea, majorly extracted from E. purpurea, E. angustifolia, and E. pallid (Gurley et al., 2012; Nagoor Meeran et al., 2021) | Polysaccharides Polyacetylenes Volatile-terpenes Caffeic acid esters Phenolic compounds Alkamides Glycoproteins |
| Elderberry (NCT03410862) | Fruit of Sambucus nigra (Porter and Bode, 2017; Wieland et al., 2021) | Anthocyanins Flavonols Phenolic acids |
| Ginseng (NCT01478009) |
Ginseng is obtained from the genus Panax most commonly from Panax quinquefolius (American variety) and Panax ginseng(Asian variety) (Mancuso and Santangelo, 2017; Fang et al., 2020; Lee and Rhee, 2021). |
Ginsenosides Triterpene glycosides |
| N-acetylcysteine (NCT04419025) |
A derivative of the cysteine amino acid (Bauer et al., 2020; Rahimi et al., 2021) | N-acetylcysteine |
| Omega-3 fatty acid (NCT04836052) | It is found mostly in flaxseeds and fatty fish, both including fish oil (Hathaway et al., 2020). | Derived as Eicosapentaenoic acid (EPA) Alpha-linolenic acid (ALA) Docosahexaenoic acid (DHA) |
| Probiotics (NCT04390477) | Obtained from bacteria like Lactobacillus acidophilus, Lactobacillus rhamnosus, and Bifidobacterium longum, and yeasts like Saccharomyces boulardii ( Kumar et al., 2020b; Singh and Rao, 2021) | Lactic acid |
| Vitamin C (NCT04682574) |
Derived from fruits and vegetables of the citrus family, and also includes tomatoes, potatoes, peppers, kiwifruit, broccoli, strawberries, and cantaloupe (Hemilä and Man, 2021). | Ascorbic acid Citric acid |
| Vitamin D (NCT04536298) | The primary ingredient is found in fatty fish (such as tuna fish and salmon fish) and their liver oils. It is also obtained from cheese, cow liver oil, and egg yolks in the form of Vitamin D1, D2, D3, D4, and D5 (Wallace et al., 2013; Butler-Laporte et al., 2021) | Ergocalciferol Cholecalciferol 22-dihydroergocalciferol Sitocalciferol Ergocalciferol with lumisterol |
| Zinc (NCT04558424) |
Zinc is mainly found in the foods like crab, whole grains, crab, beef, beans, nuts, pork, lobster, oysters, and dairy products ( Kumar et al., 2020b). | Zinc |