Awesome story. If black currants are so much richer than oranges in Vitamin C, why didnt the long distance sailors of the Age of Discovery, like the Portuguese going to India or the Spaniards going to the New World, not carry them? They only carried oranges. Puzzled.
The link between Scurvy and Vitamin C was not established until the early 1900s. Before that, pretty much only experimental evidence was able to establish what helped with scurvy, with various things found to be useful, including certain animal meats for arctic expeditions and sauerkraut, and lots of things that definitely didn't cause scurvy were blamed for it, like bad hygiene, tinned meats, alcoholism, etc.
For the British, things were especially bad. Numerous captains and sailors had personally demonstrated and convinced themselves that scurvy could be prevented with fresh citrus, but were unable to convince the "classically trained" physicians who made Naval policy, who were still pushing things like "you need more air in your tissue". One of captain Cook's expeditions had good results with malt and wort preventing scurvy, so that was official practice even as navy admirals demanded lemons.
The connection between citrus and Scurvy was finally proven in an animal model in the early 1920s, before we even understood what "Vitamins" where.
