These ideas received wide and influential backing, when James Cook set off to circumnavigate the world (1768–1771) in HM Bark Endeavour, malt and wort were top of the list of the remedies he was ordered to investigate. The others were beer, Sauerkraut (a good source of vitamin C) and Linds rob. The list did not include lemons.Cook did not lose a single man to scurvy, and his report came down in favour of malt and wort, although it is now clear that the reason for the health of his crews on this and other voyages was Cooks regime of shipboard cleanliness, enforced by strict discipline, as well as frequent replenishment of fresh food and greenstuffs. Another beneficial rule implemented by Cook was his prohibition of the consumption of salt fat skimmed from the ships copper boiling pans, then a common practice elsewhere in the Navy. In contact with air, the copper formed compounds that prevented the absorption of vitamins by the intestines.The first major long distance expedition that experienced virtually no scurvy was that of the Spanish naval officer Alessandro Malaspina, 1789–1794. Malaspinas medical officer, Pedro González, was convinced that fresh oranges and lemons were essential for preventing scurvy. Only one outbreak occurred, during a 56-day trip across the open sea. Five sailors came down with symptoms, one seriously. After three days at Guam all five were healthy again.
There have been outbreaks of the condition in refugee camps. Case reports in the developing world of those with poorly healing wounds have occurred. Human trials
Notable human dietary studies of experimentally induced scurvy were conducted on conscientious objectors during World War II in Britain and in the United States on Iowa state prisoner volunteers in the late 1960s. These studies both found that all obvious symptoms of scurvy previously induced by an experimental scorbutic diet with extremely low vitamin C content could be completely reversed by additional vitamin C supplementation of only 10 mg per day. In these experiments, no clinical difference was noted between men given 70 mg vitamin C per day (which produced blood levels of vitamin C of about 0.55 mg/dl, about 1⁄3 of tissue saturation levels), and those given 10 mg per day (which produced lower blood levels). Men in the prison study developed the first signs of scurvy about 4 weeks after starting the vitamin C-free diet, whereas in the British study, six to eight months were required, possibly because the subjects were pre-loaded with a 70 mg/day supplement for six weeks before the scorbutic diet was fed.Men in both studies, on a diet devoid or nearly devoid of vitamin C, had blood levels of vitamin C too low to be accurately measured when they developed signs of scurvy, and in the Iowa study, at this time were estimated (by labeled vitamin C dilution) to have a body pool of less than 300 mg, with daily turnover of only 2.5 mg/day.