A Narrative Review of the Safety of Anti-COVID-19 Nutraceuticals for Patients with Cancer

Abstract

Interest in dietary supplements and their efficacy in treating and preventing disease has increased greatly since the outbreak of the COVID-19 pandemic. Due to the risk of severe COVID-19 in patients with cancer, we conducted a narrative review aiming to better understand the data on the safety of the most efficacious “anti-COVID-19” nutraceuticals for patients with cancer. We conducted a PubMed database search aimed at identifying the most effective nutrients for use against COVID-19. For the identified nutraceuticals, we searched PubMed again regarding their safety for patients with cancer. Fifty-four total records (52 independent studies) were retrieved, pertaining to vitamin D, vitamin C, selenium, omega-3 fatty acids, and zinc. Vitamin D results from 23 articles indicated safe use, but two articles indicated potential harm. All 14 articles for vitamin C and five out of six articles for selenium indicated the safety of use (one study for selenium suggested harm with high-dose supplementation). Results for omega-3 fatty acids (seven articles) and zinc (one article), however, were rather mixed regarding safety. We conclude that vitamin D, vitamin C, and selenium supplements are likely safe or even beneficial at typically recommended doses; however, caution is urged with omega-3 fatty acid supplements, and zinc supplements should likely be avoided. More experimental research is needed, and nutraceutical use by patients with cancer should always be under the supervision of a healthcare team.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges

“…A growing body of evidence based on meta-analyses, observational prospective and retrospective studies, and interventional studies has shown associations between hypovitaminosis D and the occurrence of acute severe COVID-19, including an elevated risk of admission at the ICU, length of stay at the ICU, need for mechanical ventilation and mortality [ 75 , 273 , 274 ]. Vitamin D presents well-known extra-skeletal properties, including the regulation of both innate and adaptive immunity as well as enhanced activity against viruses, bacteria and fungi through the induction of cathelicidin and defensins [ 275 , 276 , 277 ]. Moreover, the beneficial effects of vitamin D have been consistently acknowledged in cardiometabolic, respiratory, neurocognitive and musculoskeletal health [ 278 , 279 , 280 , 281 , 282 , 283 ].…”

“…Interestingly, microbiota transfer from individuals with LC provoked a decline in brain cognitive properties and dysfunctional lung defense in mice, which was partially prevented by the administration of the commensal probiotic Bifidobacterium longum [ 292 ]. Probiotics, prebiotics and synbiotics, which have shown beneficial metabolic and immunologic properties [ 277 , 288 , 293 , 294 ], could be used as adjunct therapeutic tools in LC in the future. Finally, although there are no data on mycobiota alterations in LC, a study has found increased levels of fungal translocation from the gut and/or the lung epithelia, determined by β-glucan, a fungal cell wall polysaccharide, in the plasma of individuals of LC, suggesting the important role of fungal translocation in chronic immune activation due to gut barrier permeability [ 295 ].…”

The Challenges of COVID-19 with Obesity-Related Cancers

“…Several studies have demonstrated a shift towards healthier behavior after cancer diagnosis or treatment [178][179][180][181][182][183]. Whereas the majority of evidence on lifestyle changes after cancer diagnosis or treatment has been drawn from female breast cancer survivor cohorts [180,183,184], several studies have focused on hematologic malignancies [180,[185][186][187][188].…”

Perspectives and Challenges of COVID-19 with Obesity-Related Cancers

“…The lack of medications for COVID-19 in the early phases of the pandemic led the public to seek alternative therapies, including nutraceuticals. Bader-Larsen et al evaluated the safety of “anti-COVID-19” nutraceuticals in patients with cancer [ 61 ]. They reported that the use of vitamin C, vitamin D and selenium supplements is likely safe at typically recommended doses.…”