Background: Malnutrition is a serious condition that develops when the human body is deprived of or does not obtain the right amount of vital nutrients like vitamins, minerals, proteins, carbohydrates, lipids and some other essential substances that the body needs to function. It can have a significant impact on people's health including stunted growth, low body weight and muscle wasting. Purpose: This study is aimed to determine the factors that could cause malnutrition in humans, something that is considered as a major global issue nowadays and is associated with negative aspects on patient's activities. Methods: Electronic searches were conducted on the Google Scholar database, Medline and PubMed up to the 11of December 2021. All studies reporting an association between foods and malnutrition were included. Results: The search yielded 637 references, included 52 clinical trials, 11 meta-analysis, 45 randomised clinical trials (RCT) and 201 reviews. Among the manuscripts, 25 studies provided evidence for the association between malnutrition and micronutrients. The results showed that in addition to insufficient intake of the essential nutrient, several chronic diseases including gastrointestinal tract diseases, cancer and sometimes post-surgery complications are also associated with malnutrition. Conclusion: Only a limited number of studies reported a direct link between functional foods and malnutrition, which all agree that there is clear evidence in favour of functional foods being effective in preventing and reducing the impact of malnutrition. Other studies looked at for this review would suggest that they may even be effective in improving the quality of life.

The World Health Organization declared the novel coronavirus, named as SARS-CoV-2, as a global pandemic in early 2020 after the disease spread to more than 180 countries leading to tens of thousands of cases and many deaths within a couple of months. Consequently, this paper aims to summarize the evidence for the relationships between nutrition and the boosting of the immune system in the fight against the disease caused by SARS-CoV-2. This review, in particular, assesses the impact of vitamin and mineral supplements on the body’s defence mechanisms against SARS-CoV-2. The results revealed that there is a strong relationship between the ingestion of biological ingredients like vitamins C–E, and minerals such as zinc, and a reduction in the effects of coronavirus infection. These can be received from either nutrition rich food sources or from vitamin supplements. Furthermore, these macromolecules might have roles to play in boosting the immune response, in the healing process and the recovery time. Hence, we recommend that eating healthy foods rich in vitamins C–E with zinc and flavonoids could boost the immune system and consequently protect the body from serious infections. Graphical Abstract: [Figure not available: see fulltext.].