Which disease is caused by vitamin C deficiency?

It was the major cause of illness and death in sailors until the 1700's. The British Navy was the first to adopt measures to counteract it, requiring sailors to eat sourkraut and when available, citrus fruits, lemons and limes. The nickname for a British Navy sailor afterwards was 'limey'.

My guinea pigs don't produce their own vitamin C so I give them veg peppers and lots of other vitamin C foods also their pellet food contains vitamin C and they also need lots of fresh hay to keep their teeth from growing

Might be a good idea to lay in a year's worth (or more) since it's certain that fresh fruits and vegetables will be in short supply in the near future.