Vitamin supplements could reduce the risk of women getting Covid-19, a study has claimed.
King’s College London researchers used data from their Covid Symptom Study app and found taking the daily pills may reduce the virus risk by up to 14 per cent.
But the results were surprisingly specific – vitamin C and zinc, usually associated with the immune system, didn’t help and men didn’t get the same benefit as women.
Women taking vitamin D, multi-vitamins, omega-3 or probiotics appeared to be between nine and 14 per cent less likely to get Covid-19.
This means that, if the average risk of getting Covid was one in 10, those taking supplements could see their risk fall to around one in 12.
But scientists were very unsure of the results and said the study did not prove that the pills actually protected women, but may have been a sign of generally healthier lifestyles. The expert who led the study said people shouldn’t start trying to protect themselves with vitamins.
If women genuinely do get more protection, they suggested, it may be because they have generally tougher immune systems that respond better to supplements.
It comes after the Department of Health last week announced the Government would send out free vitamin D supplements to people at high risk from Covid-19.
Overwhelming scientific evidence suggests the ‘sunshine vitamin’ may offer some protection against severe Covid-19, but some studies have claimed the proof isn’t strong enough.
Some types of vitamin supplements could protect women from developing Covid-19, according to a King’s College London study (stock image)
The study was done on 372,720 users of the Covid Symptom Study app in the UK, who had reported what supplements they were taking at the start of the epidemic.
Around half of the group (175,652) said they regularly took supplements while the rest of the participants did not.
Tracking the volunteers over the course of Britain’s crisis, the researchers found that fewer women in the supplement were testing positive than would have been expected.
They wrote in the study: ‘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 in women.
‘No clear benefits for men were observed nor any effect of vitamin C, garlic or zinc for men or women.’
The study suggested that probiotics offered the biggest protection, with a 14 per cent lower risk of testing positive.
The percentage risk change does not mean that 14 per cent of women taking the supplement would test positive, but that if a group of them were compared to a group of similar women not taking the supplement, the number of positive tests would only be 86 per cent as high.
Multi-vitamins, the researchers found, reduced the positive test rate by 13 per cent, while Omega-3 lowered it by 12 per cent.
Vitamin D led to a nine per cent lower risk of testing positive for coronavirus.
The researchers suggested that women taking vitamins may have stronger immune systems and therefore be less likely to get sick with Covid-19.
They said: ‘Biological explanations include the well documented discordant immune systems between sexes that could respond differently to supplements.
‘Research indicates that females typically possess a more resilient immune system than males with higher numbers of circulating B cells when matched for age, BMI and clinical parameters, as well as a slower age related decline in circulating T- and B-cells.’
T cells and B cells are white blood cells that attack invading viruses and bacteria.
The study was based on positive test results reported by app users, meaning most of the people testing positive would have done so because they got symptoms.
Women may have differences in their immune systems that meant supplements benefitted them more than they did men, the experts said, or they may simply have reported them more accurately.
They tried to rule out the fact that those taking supplements were likely to be healthier overall, but found that the positive effect was still there even when other aspects of their lives were taken out of the equation.
And if it was a simple link to a healthier lifestyle, the researchers said, they would have expected a benefit from vitamin C, zinc or garlic supplements as well.
Professor Tim Spector, an epidemiologist who worked on the study, said: ‘Many people think that taking vitamins and other supplements can help maintain a healthy immune system, but spending your money on supplements in the hope of trying to avoid getting Covid-19 is largely unjustified.
‘You’re better off focusing on getting a healthy diet with diverse fresh vegetables and fruits, which should give you all the nutrients you need for a healthy immune system.
‘Over the weekend, the government announced it would be providing 2.7 million vulnerable individuals in England to be offered free winter supply of Vitamin D.
‘Based on our research, we cannot tell whether vitamin D supplements will have any real impact on these high risk groups.’
Professor Naveed Sattar, a metabolic medicine expert at the University of Glasgow, was not involved with the study but said: ‘These are interesting results but due to the way the study has been conducted, these data absolutely cannot tell us that taking such supplements “protects” against infection from Covid-19.
‘It may be that by being more health conscious, some women are less likely to become infected, so that it’s the behaviours that explain these results not the supplements.
‘The lack of any association in men also suggests the results may be confounded in ways not measured since there is no biological reason to think some supplements should work in women but not men. So, lets await the results of randomised trials.
‘In the meantime, as taking supplements can sometimes provide people with false reassurance, people should be advised that to lessen infection risk, continue to do the things proven to work, especially social distancing until the pandemic passes.
‘Also, keeping active and watching ones weight has more evidence to suggest it may protect against more severe COVID-19, and other chronic diseases. Supplements have no such evidence.’
The King’s research has not yet been reviewed and published in a journal, but was posted online by the scientists who did it.
One study found that 72 per cent of NHS workers in Birmingham who were lacking in the ‘sunshine vitamin’ (left column) tested positive for coronavirus antibodies in the blood — a sign of previous infection. This compared to just 51 per cent for those who had a healthy amount of the vitamin (right column)