The COVID-19 pandemic found consumers around the world seeking ways to reduce the risk of contracting the infection, or to mitigate the effects if infected. In fact, consumers with compromised baseline health and comorbidities faced an increased chance of severe disease and death, even when adjusted for age (Front Public Health. DOI: 10.3389/fpubh.2021.584182). Through the last two years, researchers around the globe continue to investigate different compounds that may support immune response and physiological wellness.
Certainly, there have also been promoters of nutritional ingredients for their potential impact on COVID-19. In Europe, food supplements are regulated as a class of food, and as outlined by the European Food Safety Authority (EFSA): “They are not medicinal products and as such cannot exert a pharmacological, immunological or metabolic action. Therefore, their use is not intended to treat or prevent diseases in humans or to modify physiological functions.”
A new review out of the University of Toledo looked at 26 peer-reviewed studies including more than 5,600 hospitalized COVID-19 patients (Clinical Nutrition ESPEN, 2022; DOI: 10.1016/j.clnesp.2021.12.033). They concluded there was no reduction in mortality from the use of vitamin C, vitamin D, or zinc by patients who were already sick and hospitalized with COVID-19; a small subset of individuals who were taking vitamin D prior to infection were examined, but not significant difference in mortality rate was seen. The use of vitamin D was associated with lower rates of intubation and shorter hospital stays, but that was not the case for zinc or vitamin C.
The researchers did acknowledge certain limitations of the study, including a lack of information on micronutrient deficiencies of individuals in the treated and control groups; an inability to assess the effect of other micronutrients; and the small number of studies with a small sample size. “Therefore,” they state, “our findings should be interpreted with caution. … Further research is needed to better understand the clinical significance of these individual micronutrient supplements in patients with SARS-CoV-2 infection.”
In a statement, authors Dr Azizullah Beran and Dr Ragheb Asslay note patients who are malnourished or deficient in micronutrients may benefit from taking supplements to address the issue. "What we're saying is this: If you don't medically need these supplements, don't take them thinking they're protective against COVID-19," Beran said. "They're not going to prevent you from getting it and they're not going to prevent you from dying."