Vitamin C not consumed. The time frame for onset of symptoms of scurvy in unstressed adults on a completely vitamin C free diet, however, may range from one month to more than six months, depending on previous loading of vitamin C. Notable human dietary studies of experimentally induced scurvy have been conducted on conscientious objectors during World War II in Britain and on Iowa state prisoners in the late 1960s to the 1980s. 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
Scurvy lambs, chickens, and ducks, along with lemons and oranges, due to which "some of our ill were cured of scurvy". Unfortunately, these travel accounts did not stop further maritime tragedies caused by scurvy, first because of the lack of communication between travelers and those responsible for their health, and because fruits and vegetables could not be kept for long on ships. In 1536, the French explorer Jacques Cartier, exploring the St. Lawrence River, used the local natives' knowledge to save his men who were dying of scurvy. He boiled the needles of the arbor vitae tree (Eastern White Cedar) to