ScienceGermanyNot enough Vitamin C? To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoScienceGermany09/17/2021September 17, 2021The market for vitamin C is booming, especially in winter, as it's considered key to a robust immune system. But the belief in a vitamin c deficiency actually stems from an ad campaign – and still brings companies large profits.https://p.dw.com/p/40RA8Advertisement