After a couple of years of mask-wearing, social distancing and hand sanitising, the common cold is back. And – according to some people – back with a vengeance. Some are calling it a “super cold” – others, “the worst cold ever”. Fortunately, there may be a way to reduce the duration of a cold: vitamin D supplements. We may suffer more common colds during the winter because we spend more time close to each other indoors. But vitamin D levels might also influence the risk of getting a cold. There are more colds during winter when vitamin D levels are lowest, and fewer colds during summer when vitamin D levels are highest. We get most of our vitamin D from the sun’s rays (80%–100%) and only a small amount from our diet. For people living at latitudes above 30 degrees, such as in the UK, there is a higher risk …