By Alice Leader2020-12-18T00:01:00+00:00 Source: Unsplash As Covid-19 took hold in the spring, shoppers frantically stocked up with products they believed would strengthen their immune systems. Yoghurt sales rose, interest grew in functional food, and sales of vitamin C supplements more than doubled in March. Own-label fruit juice benefited too. After a rotten 2019, when The Grocer reported a slump of almost £28m, private label has added a refreshing £7.7m. Volumes are up by 3.6%. And yet the category has suffered 2020’s fourth-biggest decline by absolute value: £50.2m. Own label’s gains have been consumed by the vast losses of brands. They’ve shed £57.9m and sold 23.4 million fewer litres.