The novel coronavirus disease 2019 (COVID-19) has unfolded an unprecedented worldwide public health emergency with disastrous economic consequences . Around 96 million coronavirus cases have already been identified with over half a million deaths . Despite numerous efforts by the government as well as international organizations, these numbers are still increasing with a surprising rate . Although urgent and absolutely necessary, a reliable therapeutic or vaccine is still elusive and this status quo may remain for an uncertain period of time . Taken that into account, boosting up adaptive immunity through nutritional interventions may help subside this epidemic and save many lives . This review focuses on the nexus between a balanced diet and adaptive immunity, particularly, how a poor diet may lead to compromised immunity resulting in susceptibility to viral infections . Additionally, we discuss how nutrients (vitamins, minerals, trace elements) can be used as a tool to modulate immune response and thus impede viral infections . The study also summarizes nutritional recommendations to combat COVID-19 in different countries and territories as well as dietary sources of those key nutrients . Moreover, different nutritional intervention strategies based on different age groups, physiological and medical conditions were also included, and the challenges of nutritional interventions towards the care of COVID-19 patients are also discussed . Since the availability of a drug or vaccine is still uncertain, a balanced diet or nutrient therapy can be used as a robust strategy to combat COVID-19 . Thus, we hope this review may help to make an informed decision with regard to diet choice both at individual level as well as clinical settings.