With around half the French population vitamin D deficient, a group of medical experts say mass supplementation is a low cost and low risk intervention which could save lives and curb the spread of COVID-19.

Dietary supplements containing certain plants can inhibit the immune response to COVID-19 and should not be taken by those showing symptoms of the virus, according to French regulator ANSES.

Diabetics, pregnant women, children, and those with certain food allergies in France should stop taking joint health supplements containing glucosamine and/or chondroitin sulfate due to a risk of adverse events, says national food regulator ANSES. Local supplements industry association Synadiet has insisted the products are safe and cases of adverse reactions rare.