Dietary supplements to reduce symptom severity and duration in people with SARS-CoV-2: study protocol for a randomised, double-blind, placebo controlled clinical trial.

INTRODUCTION: COVID-19 has caused morbidity, hospitalisations and deaths worldwide. Despite four approved vaccines for COVID-19 in Canada, there is still a need for effective treatments, especially for people in the community. Vaccine efficacy is not 100% and long-term efficacy is still unknown. Furthermore, there are challenges to herd immunity including vaccine hesitancy and underlying conditions preventing vaccination. We aim to explore if the nutrients vitamin C, vitamin D, vitamin K2 and zinc are an effective treatment option for outpatients diagnosed with COVID-19. The primary outcome is the difference in participant-reported overall health; secondary outcomes include the effect on health status, symptom severity and duration, frequency and length of hospitalisations and mortality. METHODS AND ANALYSIS: This study is a two-arm, parallel-group, double-blind, placebo-controlled, phase III randomised controlled trial. 200 patients will be recruited remotely from COVID-19 test centres in Ottawa, Canada associated with The Ottawa Hospital. Overall health will be measured using the EuroQol Visual Assessment Scale; health status will be measured using the EuroQol 5-dimension 5-level questionnaire; symptom severity and duration will be measured using an independently developed questionnaire; analyses will use an area under the curve approach and compare mean scores using unadjusted t tests. Study data will be recorded on electronic case report forms using the Research Electronic Data Capture platform. An independent data safety and monitoring board will perform ongoing review of the study for feasibility and safety. ETHICS AND DISSEMINATION: This study has received ethical approval from the research ethics boards of the Canadian College of Naturopathic Medicine and the Ottawa Health Sciences Network, as well as regulatory approval from the Therapeutic Products Directorate and Natural and Non-Prescription Health Products Directorate of Health Canada. Results will be published in a peer-reviewed scientific journal with open access. TRIAL REGISTRATION NUMBER: NCT04780061.

Elderberry for prevention and treatment of viral respiratory illnesses: a systematic review.

BACKGROUND: Elderberry has traditionally been used to prevent and treat respiratory problems. During the COVID-19 pandemic, there has been interest in elderberry supplements to treat or prevent illness, but also concern that elderberry might overstimulate the immune system and increase the risk of 'cytokine storm'. We aimed to determine benefits and harms of elderberry for the prevention and treatment of viral respiratory infections, and to assess the relationship between elderberry supplements and negative health impacts associated with overproduction of pro-inflammatory cytokines. METHODS: We conducted a systematic review and searched six databases, four research registers, and two preprint sites for studies. Two reviewers independently assessed studies for inclusion, extracted data from studies, assessed risk of bias using Cochrane tools, and evaluated certainty of estimates using GRADE. Outcomes included new illnesses and the severity and duration of illness. RESULTS: We screened 1187 records and included five randomized trials on elderberry for the treatment or prevention of viral respiratory illness. We did not find any studies linking elderberry to clinical inflammatory outcomes. However, we found three studies measuring production of cytokines ex vivo after ingestion of elderberry. Elderberry may not reduce the risk of developing the common cold; it may reduce the duration and severity of colds, but the evidence is uncertain. Elderberry may reduce the duration of influenza but the evidence is uncertain. Compared to oseltamivir, an elderberry-containing product may be associated with a lower risk of influenza complications and adverse events. We did not find evidence on elderberry and clinical outcomes related to inflammation. However, we found evidence that elderberry has some effect on inflammatory markers, although this effect may decline with ongoing supplementation. One small study compared elderberry to diclofenac (a nonsteroidal anti-inflammatory drug) and provided some evidence that elderberry is as effective or less effective than diclofenac in cytokine reduction over time. CONCLUSIONS: Elderberry may be a safe option for treating viral respiratory illness, and there is no evidence that it overstimulates the immune system. However, the evidence on both benefits and harms is uncertain and information from recent and ongoing studies is necessary to make firm conclusions.