Maintaining a healthy weight, exercising, being Vitamin D sufficient, moderating alcohol consumption and not smoking all have beneficial effects on general health and may reduce the risk of poor outcomes from Covid-19, the health watchdog has said.
It published its advice to the National Public Health Emergency Team on public health interventions and modifiable health-related risk factors to prevent Covid-19 or to reduce the risk of serious disease.
The Health Information & Quality Authority examined 46 studies which focused on modifiable health-related risk factors and found mixed results reported.
Interventions considered included drug (excluding vaccines) and non-drug interventions.
HIQA found that there was a lack of high quality evidence to suggest that any of the examined interventions were effective at reducing the risk of COVID19.
It said there was insufficient evidence on whether ivermectin (conventionally used to treat parasitic worm infestations) or bamlanivimab (an immune therapy) can be safely used to prevent or reduce the severity of Covid-19.
It therefore has advised these drugs should not be used outside of well-designed, regulated clinical trials.
The European Medical Agency has strongly advised against the use of ivermectin to prevent or treat Covid-19.
While bamlanivimab has been approved by the EMA for emergency use in treating patients with severe Covid-19 disease, it is not approved to prevent Covid-19.
Dr Máirín Ryan, HIQA's deputy CEO and Director of Health Technology Assessment, said the regulator cannot make a population recommendation that Vitamin D will prevent people from acquiring Covid-19 infection or having a poorer outcome.
But she said it is common sense that taking Vitamin D boosts the immune system, and a healthy immune system ensures that people are better prepared if they encounter the virus.
Speaking on RTÉ's Drivetime, Dr Ryan said that Vitamin D deficiency is associated with poorer outcomes such as contracting Covid-19 in the first place, or having a more severe strain of the disease, but it is association and not causation data.
She said the public health advice on Vitamin D is that those at risk of being deficient in the vitamin, especially frail, older people, who may not spend that much time outdoors, should take a supplement.
