Abstract
Globally, the pandemic of coronavirus disease -2019 (Covid-19) has increased people's focus on the importance of consuming a healthy diet to promote their immune defenses. It has been established that many factors influence the immune system, including genetics, hormonal, and nutrition status. This study reviews the effect of the different dietary patterns and some selected micronutrients that most populations suffer from its deficiency, such as vitamin D, zinc, selenium, and iron, on the immune system. The aim was to focus on the impact of different diets and many nutrients on immunity which may protect or ameliorate COVID-19 patients. Mediterranean diet (Mid Diet) is characterized by excellent vegetables, fruits, seeds, seafood, and moderate meat. This dietary pattern is linked to a well-functioning immune system. Med Diet contains many antioxidants as vitamin C, beta-carotene, and polyphenols that exert immunomodulatory and anti-inflammatory effects. Med Diet may be considered an effective and reasonably simple way to attenuate the intensity of COVID-19 infection. The vegetarian diet (Veg Diet), the plant-based diet, is also linked to healthy immune responses. It plays a criteria role in activating and strengthen both innate and adaptive immunity. It increases gutmucosa health and reduces autoimmunity related disorders. Contrariwise, the western diet (West Diet) is a popular pattern intake rich in carbohydrates, salt, saturated and trans lipid, while lacking in complex carbohydrates and fibers. This dietary pattern leads indirectly to increase inflammatory markers, obesity, and many diseases. Available evidence indicates that several micronutrients,including vitamin D, zinc, selenium, and iron, play an immune-supporting role, modulate the immune activity, and lower the possibility of infection.Optimizing vitamin D and zinc status definitely has advantages in COVID-19 patients.Evidence showed that various diet and different micronutrients play a role in the immune system and COVID-19 patients.