Folic acid - importance for human health and its role in COVID-19 therapy.

Folic acid (folacin, B9) is a vitamin that performs many very important functions in the human body, and its inadequate level - deficiency as well as excess, may contribute to an increased risk of developing many disease processes. The aim of this study was to analyze the available scientific literature on folic acid and its impact on human health. A systematic review of the studies, published until November 2022, was made on the basis of searching bibliographic databases such as: PubMed, Elsevier and Google Scholar. The following keywords and combinations were used: folic acid, folate, folic acid supplementation, folate deficiency. Folic acid, thanks to its high biological activity, has a direct and indirect effect on the metabolism of the human body cells. It plays a very important role, among others in the prevention of neural tube defects and megaloblastic anemia, the proper functioning of the nervous system, as well as reducing the risk of developing certain cancers. Currently, the important role of folic acid in maintaining the proper functioning of the immune system is also emphasized, which is of particular importance both in the prevention and in the situation of SARS-CoV-2 (COVID-19) infection. The effects of deficiency and excess of vitamin B9 may turn out to be dangerous to health and even life. There is a need for nutritional and health education of the society regarding the importance of folic acid for human health, due to the presence of large deficiencies in the population, which is particularly important for some social groups, such as, for example, women of procreation age, pregnant or breastfeeding, people with a nutrient malabsorption, and people who smoke or abuse alcohol.

Vitamin D in SARS-CoV-2 infection.

Background: Background. SARS-CoV-2 virus is one of the largest RNA viruses, included in the coronavirus group, showing tropism to airway epithelial cells. SARS-CoV-2 causes an acute respiratory infectious disease, Covid-19. According to WHO reports, mortality due to Covid-19 is higher in the elderly and in those burdened with comorbidities such as diabetes, obstructive pulmonary disease, coronary artery disease, cancer, hypertension, hepatitis B, obesity or chronic kidney disease. Objective: The aim of the study was to review the current literature on the influence and importance of vitamin D levels on the course of SARS-CoV-2 infection. Material and method: A systematic review of studies published from January 1, 2009 to June 31, 2021 has been performed. For this purpose, bibliographic databases such as PubMed and Scopus were searched. The following keywords and combinations were used: Covid-19, vitamin D, 25-hydroxy-vitamin D, vitamin D supplementation, SARS-CoV-2. Results: It has been shown that vitamin D plays an important role in the mechanisms of the innate immunity in the course of the acute respiratory infections. The overlapping factors of the severity of COVID-19 disease, vitamin D deficiency, and the prevalence of obesity, age scare, ethnicity, has led some researchers to hypothesize that vitamin D supplementation may be promising as a preventive or therapeutic measure for COVID-19. Conclusions: A very important factor that has an immunomodulatory character is vitamin D, the adequate supplementation of which can be a preventive or therapeutic measure in case of SARS-CoV-2 infection, especially in elderly people, with obesity and other chronic diseases.