- A study found that probiotics, vitamin D, omega-3 fatty acids and multivitamins may decrease one's chances of testing positive for Covid-19
- Vitamin C, garlic or zinc did not appear to have the same benefits
- Supplements worked better for women than for men
New research has found a small but significant link between the use of probiotics, omega-3 fatty acids, multivitamin or vitamin D supplements, and a lower risk of testing positive for SARS-CoV-2, the virus that causes Covid-19.
However, according to the study published in BMJ Nutrition, Prevention & Health, these benefits were experienced by women, but not by men.
The researchers used data from people who self-reported regular dietary supplement use during the three months up to 31 July 2020.
The Covid-19 Symptom Study app was used by 445 850 subscribers from the United States, United Kingdom and Sweden to self report their supplement usage.
Which supplements work?
The study’s findings show a significant association between users of omega-3 fatty acid, probiotic, multivitamin or vitamin D supplements and a lower risk of testing positive for infection with SARS-CoV-2.
The study further found that taking vitamin C, zinc, or garlic supplements was not linked with a lower risk of testing positive for the virus.
No clear benefits for men
The researchers observed that while there was a small but significant association between the use of probiotics, omega-3 fatty acid, multivitamin or vitamin D supplements and a lower risk of testing positive for SARS-CoV-2 in women, there were no clear benefits for men.
Regarding vitamin D specifically, there was a modest protective effect on infection, with a 9% reduction in the risk of testing positive for SARS-CoV-2 in the UK, 24% in the US cohort and 19% in the Swedish group.
The protective effect in those taking multivitamin supplements was a 13% reduction in risk of testing positive for SARS-CoV-2 in the UK, 12% in the US and 22% in Sweden.
According to the scientists, there may be a number of factors that make these supplements work better in women than in men.
“It is therefore plausible that: (i) supplements could better support the immune system of females than males, although the lack of consistency between countries is problematic; (ii) differences in body weight and body composition between males and females could mean that supplement dosing on a per body weight basis may be higher in females; (iii) there could be residual confounding due to sex differences in health-related behaviours, including Covid-19."