It may well be that Notherners and Scots have a greater affection for preserved fruit, they were the main source of Vitamin C in the winter, and in poor families the main source full stop. Older readers will remember Rosehip Syrup, Sloe Gin is also a way of preserving Ascorbic Acid. Glace Cherries will stop you getting scurvy, worth remembering in a nutritional bind, also a good source of vitamin A. So a balanced diet could be Glace Cherries and Marmite, and lots of sunshine.