LONDON, 20 April 2021:
Women regularly taking multivitamins, probiotics, omega-3, or vitamin D supplements are less likely to contract the coronavirus infection, a new study says.
Contrary to a common belief, the latest study published by BMJ Nutrition Prevention and Health yesterday has found no effect of vitamin C, garlic, or zinc on reducing the risk of getting infected with the virus.
“In women, we observed a modest but significant association between use of probiotics, omega-3 fatty acid, multivitamin or vitamin D supplements and lower risk of testing positive for SARS-CoV-2,” said the researchers of the study.
The study “found no clear benefits for men.”
The authors, however, called for randomised controlled trials “to confirm the observational findings before any therapeutic recommendations can be made.”
Experts had emphasised the benefits of certain nutritional supplements in preventing and treating Covid-19 since the pandemic began last year.
There was a significant increase in the vitamin C and other multivitamin supplement sales in the UK in the run-up to the first lockdown that began on March 23 last year when infections surged.
Dietary supplements have long been associated with maintaining a healthy immune system and reduced the risk of respiratory infections.
But it is not known if supplements may be linked to lowering the risk of contracting the coronavirus.
To establish a possible link, the researchers at Imperial College London investigated whether users of the Covid-19 Symptom Study app who regularly took dietary supplements were less likely to test positive for the coronavirus infection.
The app was launched in the UK, US and Sweden in March 2020 to collect data on the evolution of the pandemic.
On first use, the app recorded self-reported location, age, and core health risk factors.
The participants later provided daily updates on symptoms, healthcare visits, coronavirus test results, and if they were self-quarantining or seeking healthcare.
The researchers analysed information provided by 372,720 UK app users (aged 16–90 years) who self-reported information regarding regular dietary supplement usage and the outcome of a Covid-19 test.
The study sample was predominantly female (66.8%).
The analysis was carried during the first wave of the virus in May, June, and July last year.
Some 47% of the respondents self-reported using supplements regularly since the beginning of the pandemic, while others said they were not taking any supplements.
Of these, 23 521 individuals tested positive for the virus, and 349,199 tested negative between May and July.
The findings showed “a significant association between users of omega-3 fatty acid, probiotic, multivitamin or vitamin D supplements and lower risk of testing positive for (coronavirus) infection.”
“We saw no protective effects of zinc, garlic or vitamin C.” Both zinc and vitamin C have been previously suggested to support the immune system and to prevent respiratory infections.
A meta-analysis of vitamin C showed no preventive benefit but severity reduction and a modest decline in symptom duration.