The supplementation of vitamin C on regular basis has modest but consistent effect in shortening the infection period of common cold. Moreover, administration of vitamin C in high doses before or after the appearance of flu symptoms reduces severity of illness. The risk of common cold decreases by vitamin C supplementation without any adverse effects. Vitamin C boosts Targetmol’s Methyl acetate,Methyl acetate antiviral immune responses against the influenza A virus by increasing the production of interferon. As vitamin C has effective role in respiratory tract infections and antiviral immune responses, vitamin C intake is crucial particularly in micronutrient deficient individuals with high risk of COVID, although vitamin C supplementation to prevent and treat acute respiratory diseases is inconclusive. Adequate vitamin C consumption in diet may be beneficial in COVID prevention or prognosis.The dietary recommendation may be achieved through natural foods such as citrus fruits, kiwi, broccoli, and other products. Recent epidemiological data support the importance of vitamin D in COVID severity and complications through cytokines and regulation of cell signaling pathways. Vitamin D is crucial in functionality of immune cells and plays a critical role during viral infections by modulating inflammatory responses. The presence of vitamin D receptors on T and B immune cells helps in proliferation, inhibition, and differentiation of these cells. In experimental models of lipopolysaccharideinduced inflammation, vitamin D is directly linked with lower concentrations of proinflammatory cytokine interleukin. A sufficient vitamin D serum level is linked to a switch from pro to anti inflammatory profiles in older adults. This impact on the regulation of inflammation is of particular importance in older adults, the obese, and those with chronic conditions as they may already be preset for higher inflammatory responses if exposed to COVID.Lower level of vitamin D has a direct link with higher respiratory infection rates, and the effect was more pronounced in individuals having underlying lung conditions. Casecontrol studies have also declared that increased risk of infection is due to low level of vitamin D. Vitamin D supplementation reduces the risk of acute respiratory infections, while a higher blood vitamin D status has been associated with a small reduction in risk of pneumonia. Vitamin D deficiencies probably increase the risk of upper respiratory viral infections, although the size of this effect is small.The humeral immunity increases in pediatric patients by vitamin D supplementation after influenza vaccination. Older age, obesity, being male, and having preexisting chronic conditions are risk factors for vitamin D deficiency. Importantly, it is evident that there is a worldwide association between northern latitude and increased COVID mortality. Recent reports have indicated that those residing at higher latitudes or with darker skin pigmentation may be particularly affected by COVID.While there could be various explanations for this, it supports the assumption that sunlight exposure and hence vitamin D status could be impacting on COVID severity.Several mechanisms are proposed to establish a role between vitamin D deficiency and increased risk of viral infections, but all underlying mechanisms are still inconclusive. The potential mechanisms include the modulation of immunoregulatory defense, induction of autophagy and apoptosis, antiviral immune induction, and genetic or epigenetic regulations.