But if you are feeling run down, is supplementation the best thing to do? Rest and a well-balanced diet aside, O’Shaughnessy says that he recommends taking vitamin C and D (the latter being the only supplement the NHS advises most of us to take during the winter months).

“I also like to take beta glucans, which are from fungi and have some immune supportive properties,” he says. Those beta glucans are a type of soluble fibre thought to help activate the immune cells and protect against infection.

While there are probably loads of things you could do to make yourself feel a bit better (quitting your job not being an option), there’s nothing wrong with taking supplements only when you’re feeling a bit grim. But once you’re out of the woods, it might be worth getting checked by your GP to see if you’re actually deficient in anything, and working out how you might make up any lower levels over a sustainable period of time. It’s important not to blindly take supplements, so if you do that, be sure to assess a few months down the road to see if you still need to take them.

Can you overdose on supplements? Here’s why it’s fine to only supplement when you’re feeling run down