Vitamin D, omega-3 and probiotics lower risk of testing positive for COVID-19: BMJ
Women taking probiotics, vitamin D supplements, omega-3 fatty acids, and multivitamins are at a slightly lower risk of testing positive for SARS-CoV-2, finds a recent study in the journal BMJ - Nutrition, Prevention & Health. Further, the researchers found no clear benefits for men or any effect in those taking zinc, vitamin C or garlic.
Since the beginning of the current coronavirus pandemic, many prominent medical entertainment personalities on television and social media have been promoting the use of specific dietary supplements in both prevention and acute treatment of infection with SARS-CoV-2. However, there is a lack of a scientific evidence supporting the role of dietary supplements in ameliorating SARS-CoV-2 infection.
Against the above background, Cristina Menni, Department of Twin Research and Genetic Epidemiology, King's College London, London, UK, and colleagues aimed to investigate whether users of the COVID-19 Symptom Study app who regularly took dietary supplements were less likely to test positive for SARS-CoV-2 infection.
For the purpose, the researcher conducted an app-based community survey. 445 850 subscribers of an app that was launched to enable self-reported information related to SARS-CoV-2 infection for use in the general population in the UK (n=372 720), the USA (n=45 757) and Sweden (n=27 373).
They were asked to give information on self-reported regular dietary supplement usage (constant use during previous 3 months) in the first waves of the pandemic up to 31 July 2020.
Key findings of the study include:
- In 372 720 UK participants (175 652 supplement users and 197 068 non-users), those taking probiotics, omega-3 fatty acids, multivitamins or vitamin D had a lower risk of SARS-CoV-2 infection by 14%, 12%, 13% and 9%, respectively, after adjusting for potential confounders.
- No effect was observed for those taking vitamin C, zinc or garlic supplements.
- On stratification by sex, age and body mass index (BMI), the protective associations in individuals taking probiotics, omega-3 fatty acids, multivitamins and vitamin D were observed in females across all ages and BMI groups, but were not seen in men.
- The same overall pattern of association was observed in both the US and Swedish cohorts.
"Given the interest in supplements during the pandemic, large randomised controlled trials of selected supplements testing their protective effects, and also possible adverse effects, on disease severity are required before any evidence-based recommendations can be made. We eagerly await the result of ongoing trials, including of vitamin D, omega-3 fatty acids and probiotics and COVID-19 risk," wrote the authors.
The study titled, "Modest effects of dietary supplements during the COVID-19 pandemic: insights from 445 850 users of the COVID-19 Symptom Study app," is published in the journal BMJ - Nutrition, Prevention & Health.