...The loss of knowledge has been attributed to several factors. Firstly, Lind showed in his work that there was no connection between the acidity of the citrus fruit and its effectiveness at curing scurvy. In particular, he noted that acids alone (sulphuric acid or vinegar), would not suffice. Despite this, it remained a popular theory that any acid could be used in place of citrus fruit. This misconception had significant consequences.
When the Royal Navy changed from using Sicilian lemons to West Indian limes, cases of scurvy reappeared. The limes were thought to be more acidic and it was therefore assumed that they would be more effective at treating scurvy. However, limes actually contain much less vitamin C and were consequently much less effective. Furthermore, fresh fruit was substituted with lime juice that had often been exposed to either air or copper piping. This resulted in at least a partial removal of vitamin C from the juice, thus reducing its effectiveness.
The discovery that fresh meat was able to cure scurvy was another reason why people no longer treated the condition with fresh fruit. This discovery led to the belief that perhaps scurvy was not caused by a dietary problem at all. Instead, it was thought to be the result of a bacterial infection from tainted meat. In fact, the healing properties of fresh meat come from the high levels of vitamin C it contains.
Finally, the arrival of steam shipping substantially reduced the amount of time people spent at sea, therefore the difficulties in carrying enough fresh produce were reduced. This decreased the risk of scurvy so that less effective treatments, such as lime juice, proved effective enough to deal with the condition most of the time. Unfortunately, this meant that knowledge of the most effective treatment for scurvy was gradually lost....
Ah thanks