Nutritional risk of vitamin D, vitamin C, zinc, and selenium deficiency on risk and clinical outcomes of COVID-19: A narrative review

Abstract

The pathogenicity of the current coronavirus disease shows postulates that optimal status of essential nutrients is crucial in supporting both the early viraemic and later hyperinflammatory phases of COVID-19. Micronutrients such as vitamin C, D, zinc, and selenium play roles in antioxidant, antiinflammatory, antithrombotic, antiviral, and immuno-modulatory functions and are useful in both innate and adaptive immunity. The purpose of this review is to provide a high-level summary of evidence on clinical outcomes associated with nutritional risk of these micronutrients observed in patients with COVID-19. A literature search was performed on PubMed and Google Scholar to obtain findings of crosssectional and experimental studies in humans. The search resulted in a total of 1212 reports including all nutrients, but only 85 were included according to the eligibility criteria. Despite the diversity of studies and the lack of randomized clinical trials and prospective cohorts, there is evidence of the potential protective and therapeutic roles of vitamin C, D, zinc, and selenium in COVID-19. The findings summarized in this review will contribute to guide interventions in clinical practice or in future clinical studies.

The Perception of Minerals and Their Prevalence in Fortified Foods and Supplements in Japan

“…Therefore, it is important to strengthen the immune system against SARS-CoV-2 infection [42,43]. It is well-known that malnutrition attenuates the immune system and might be a risk of infection and exaggeration of COVID-19; especially, the association with deficit of vitamin C, vitamin D, zinc, and selenium has been thoroughly studied [44,45]. In the case of each mineral, deficiency or lower plasma levels of zinc [46,47], calcium [47], and selenium [48,49] in COVID-19 patients was reported.…”

Vitamin D prescribing practices among clinical practitioners during the COVID‐19 pandemic

“…[4][5][6][7][8] Interestingly, some of these factors have also been linked to higher risk of vitamin D deficiency, 9 while a large number of studies regarding the possible association between vitamin D levels and the risk of COVID-19 contraction and worse outcomes have been published. [10][11][12][13][14][15] This link between vitamin D levels and COVID-19 outcomes can be explained based on the immunomodulatory actions of calcitriol, the interaction with the renin-angiotensin-aldosterone system (RAAS), as well as its protection against endothelial dysfunction and thrombosis. [16][17][18] Moreover, vitamin D suppresses cytokine production by simultaneously boosting the innate immune system, thus reducing the SARS-CoV-2 load, and decreasing the overactivation of the adaptive immune system to immediately respond to the viral load.…”

“…Several factors have been studied as possibly affecting the transmission and outcomes of COVID‐19, including age, ethnicity, metabolic diseases, as well as environmental and social parameters such as temperature and air pollution 4–8 . Interestingly, some of these factors have also been linked to higher risk of vitamin D deficiency, 9 while a large number of studies regarding the possible association between vitamin D levels and the risk of COVID‐19 contraction and worse outcomes have been published 10–15 . This link between vitamin D levels and COVID‐19 outcomes can be explained based on the immunomodulatory actions of calcitriol, the interaction with the renin‐angiotensin‐aldosterone system (RAAS), as well as its protection against endothelial dysfunction and thrombosis 16–18 .…”

COVID-19 Disease and Outcomes among Critically Ill Patients: The Case of Medical Nutritional Therapy

“…Are there any data on best nutrition support practices? Unfortunately, there are no data from randomized clinical trials, with the exception of some micronutrient supplementation studies with immunomodulating actions [ 11 ]. Although reduced levels of vitamin C, D, Zinc and selenium may be considered as a risk factor for patients with COVID-19, data from published studies so far highlight the lack of well-designed clinical intervention, evaluating the effect of the administration of either individual nutrients or their combination [ 11 ].…”

“…Unfortunately, there are no data from randomized clinical trials, with the exception of some micronutrient supplementation studies with immunomodulating actions [ 11 ]. Although reduced levels of vitamin C, D, Zinc and selenium may be considered as a risk factor for patients with COVID-19, data from published studies so far highlight the lack of well-designed clinical intervention, evaluating the effect of the administration of either individual nutrients or their combination [ 11 ]. Kakavas et al, in the present SI hypothesized that immunonutrient administration could be associated with a reduction in the de novo synthesis and/or release of histamine and other mast cell mediators that could mediate, at least in part, the immune and microvascular alterations present in COVID-19 [ 12 ].…”