Coronavirus: should I take zinc supplements to boost my immune system?

Many people are taking supplements to try and keep COVID-19 at bay. Do they work?

The best way to protect yourself from COVID-19 is to carry out social distancing and regularly wash your hands. But as shops and workplaces reopen, what about bolstering your body by taking other remedies – such as zinc supplements – which have been vaunted as a way to help prevent COVID-19?

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Your body contains around two to three grams of zinc. There are more than 300 enzymes whose activity is linked to zinc, which helps explain why your body needs it for a wide range of roles, including wound healing, protein synthesis and ensuring a fully functioning immune system.

So you certainly need zinc to stay healthy, but is there any benefit from taking supplements?

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The best evidence comes from intervention studies, where scientists have given zinc lozenges to people who are exposed to the common cold. In a meta-analysis published in 2017 in the journal JRSM Open, they looked at people taking zinc lozenges in the form of zinc acetate or zinc gluconate and found that taking zinc had an effect.

In three trials where people were given zinc acetate, or a placebo, the zinc acetate shortened the duration of a cold by 40 per cent. Similarly, in four trials where people were given zinc gluconate, or a placebo, those taking the zinc gluconate found it reduced the duration of a cold by 28 per cent.

© Jason Raish
© Jason Raish

The team behind the meta-analysis concluded that “common cold patients may be encouraged to try zinc lozenges for treating their cold”.

So why did the zinc supplements make a difference? We know that zinc is important for your innate immune system, the part of your immune system that is constantly on the alert for infections and is first to act.

Zinc helps white cells like monocytes bind to infected cells and either phagocytose them (‘eat’ them) or poison them. If you are zinc-deficient there is also a decrease in the activity of white cells called natural killer cells.

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The people who seem to get the most benefit from taking zinc are the over-60s, as zinc deficiency is common in older age groups. Taking zinc supplements has been shown to suppresses the formation of pro-inflammatory cytokines, the sort that can lead to a ‘cytokine storm’. This is when the immune system overreacts and attacks healthy cells – this seems to be what causes death in many older people who get COVID-19.

You get zinc from eating shellfish, fish and meat. You also find it in nuts, seeds and legumes, but in a less absorbable form.

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So should I be taking zinc? I’m sure I get enough in my diet, and there is no real evidence it will help with COVID-19, but if I get symptoms I probably will start taking zinc supplements, just in case. But don’t take more than 40mg per day and consult your doctor if you are taking other medication.