Do vitamin supplements decrease the risk of contracting Covid-19?

A large-scale study published on April 19 by the online scientific journal BMJ, which specializes in health and preventive nutrition, indicates that the use of multivitamins, omega-3s, probiotics and vitamin D supplements may decrease the risk of testing positive for the SARS-CoV-2 virus, responsible for Covid-19. The effect, however, was only felt in women. Nor are all vitamin complexes showing good results: the use of vitamin C, zinc and garlic supplements in the composition did not indicate a lower risk of contracting the virus.

Although vitamin supplements help the immune system, there is still no scientific confirmation regarding any compound that could actually decrease the risk of contracting the virus responsible for Covid-19 – more studies still need to be done.

How the research was done

The researchers used data from 372,720 users of a Covid-19 symptom analysis application available for adults in the UK as a source for the study. The information was provided by the population during the evolution of the pandemic, since March 2020, when the app was launched.

The application received data such as location, age and the main risk factors for the health of its users, initially. As the pandemic progressed, daily information was also requested about events related to Covid-19, such as symptoms, disease detection tests and health care being taken – even users without symptoms were encouraged to keep the app up to date.

The survey data were obtained using an app. Majority was women.The survey data were obtained using an app. Majority was women.Source: Pixabay

The mechanism used by the research was to correlate the answers about the use of dietary supplements with the results of tests for detection of Covid-19 made by the users. The data chosen for analysis were collected during the first pandemic wave recorded in the United Kingdom, between May and July 2020.

A total of 175,652 users of the app took supplements regularly, compared to 197,068 who preferred not to use multivitamins and the like. About 67% of respondents were women, more than half slightly overweight (with a body mass index of 27). In all, 23,521 of the participants tested positive for SARS-CoV-2 during the study period.

Main results

Taking into account factors that could influence the results, such as pre-existing health conditions and the usual diet, the research came to the following result: probiotics were the champions – decrease the risk of SARS-CoV-2 infection by 14%; multivitamins were in second place, decreasing the risk by 13%; omega-3s, on the other hand, decreased the risk by 12%, while vitamin D supplements reduced the risk of infection by 9%. Vitamin C, zinc and garlic supplements in the composition did not obtain significant results in the study.

Analyzing the sex, weight and age of the researched population, the team concluded that the decreased risk of infection by Covid-19 with the use of supplements was only observed in women. To validate the study, the researchers also analyzed the database of users of the application from two other countries: 45,757 from the United States and 27,373 from Sweden. The results were similar. In the United States, probiotics obtained an 18% decrease in the risk of infection, while multivitamins reached 12%; omega-3 obtained 21% and vitamin D 24%. In Sweden, the risk reduction found was 18% in the use of probiotics, 22% with multivitamins, 16% with omega-3 and 19% with vitamin D.

Probiotics, multivitamins, omega-3 and vitamin D had positive results.Probiotics, multivitamins, omega-3 and vitamin D had positive results.Source: Pixabay

As it is an observational study, it was not possible to establish the cause of the risk decrease. There are also limitations, such as the fact that the study is based on data sent by users and did not take into account doses or all the ingredients in the composition of the supplements. However, the researchers note that their effects are significant and may offer a therapeutic line in the future, as long as large clinical trials are carried out.

“So far, there is little convincing evidence that taking nutritional supplements has any therapeutic value other than maintaining the body’s normal immune response,” says Professor Sumantra Ray, one of the owners of the online magazine in which the study was published, in the article, the BMJ. Ray further warns that more rigorous studies are needed before conclusions can be drawn.

Leave a Comment