Introduction:
The end of 2019 was marked by the rapid epidemic of Severe Acute Respiratory Syndrome (SARS) due to COVID-19 in Wuhan, China. The most common medical treatment pathways have been supportive rather curative. However, multiple studies have found impaired levels of micronutrients in patients. These associations with disease outcomes could be taken into consideration. Micronutrient deficiencies (MNDs) are a global health concern and an underdiagnosed epidemic highly affecting developing countries. The most vulnerable groups for MNDs are women, children, and the elderly. MNDs can cause a huge number of morbidities and mortalities indicating the significance of effective prevention and treatment strategies to further control the consequences.

Objectives:
The aim of this study was to review and summarise the literature on dietary intake and supplementation and the associations of micronutrient insufficiencies with disease susceptibility and severity of symptoms.

Methods:
A narrative review of the literature was conducted through two online databases in PubMed and Google Scholar. Articles that were published since the start of the pandemic and had different types of study designs were included. Of 5,073 identified articles, 38 studies were selected according to defined inclusion criteria.

Results:
The most prevalent nutritional insufficiencies and their associations with prevention and disease severity among COVID-19 patients were identified. Patients had impaired levels of a wide range of micronutrients, including vitamin D, Zinc, and Selenium followed by vitamins B1 and C.

Conclusion:
Malnutrition and undernutrition are global concerns and modifiable risk factors in many countries impacting the prevalence of infectious diseases. Medical nutrition therapy (MNT) is an overarching method to combat nutritional deficiencies. Thus, alongside preventive measures like acquiring herd immunity by vaccination, achieving an optimal nutritional status could be a contributing factor for better outcomes in patients.