This is my alternative theory for scurvy.
Scurvy was found among sailors on ships. But the ship’s wood was treated with arsenic to ward off barnacles and other pests. The sailors maintained the arsenic treatment to the wood. Arsenic was used much as a preservative for the foods that were being shipped back in those days.
Sailors drank arsenic tonic water, as a pepper-upper.
The original scurvy cure was “scurvy grass”, known for its high sulfur content, which combines with heavy metals enabling it to be passed out through the kidneys.
Captain Cook originally used onions (not citrus), also high in sulfur.
The stories about oranges and lemons are a cover-up for the history of scurvy as arsenic poisoning. They threw a bone to the vitamin C loving health nuts who helped to spread the stories.