Scurvy was a disease found in humans, resulting from a deficiency of Vitamin C, and common among sailors on Earth. On Safehold, the Book of Pasquale, when properly followed, prevented the onset of scurvy in all but the most desperate situations.
After their capture, the crew of the Charisian galleon HMS Dancer suffered from scurvy due to a meager diet that blatantly violated Pasquale's laws. (HFAF)