Explanation: Scurvy is a disease caused by Vitamin C deficiency. Thing is, it’s actually pretty hard to get scurvy - most of Europe didn’t have scurvy outbreaks of any kind except during periods of starvation (one account of the Roman Legions with scurvy is noted in Germania, and it was quickly solved just by eating local greens), and in those periods scurvy was usually not recognized as a separate affliction. On account of, you know, starving to death. When scurvy DID become a problem was the Age of Sail - when long-distance voyages on ships became the norm. On a ship, you’d be eating salt pork, hardtack (a kind of particularly unpleasant biscuit), and booze - and after several weeks at sea, THAT particular diet DOES start to drop your Vitamin C levels low enough to be a problem.

Thing is, having not dealt with it in such a long period of time, Europe had no fucking clue what this new disease was, or how to fix it. The cure for scurvy was discovered at least 4 separate times between 1500 AD and 1800 AD, and each time, it was forgotten about because of the low level of communication and information preservation experienced by Europeans in the New World. On at least one occasion, Native American tribes taught the Euros how to deal with it (eat local plants), and the damn ungrateful white man just up and forgot to pass it on.

Eventually the cure was stumbled upon by the Brits - citrus juice. Especially lemon juice. Of course, things couldn’t be that simple, no no no, first, they staggered the ships so that many did NOT carry lemon juice. Why? To keep the secret of curing scurvy from the French and Spanish. After that little period was over, they swapped from lemon juice (very effective) to lime juice (not nearly as effective) because it was cheaper - hence the term ‘Limey’ for a Brit. And, to top it all off they boiled it down to reduce storage space, destroying most of the Vitamin C and ensuring that scurvy still popped up on ships intermittently on long journeys.

All of this contributed greatly to the cause of scurvy STILL not being known until the early 20th century, because of all the confusion around what did and did not cure it. Insanity!