“Vasco da Gama began his expedition to India in 1497 and when his ships arrived on southeast coast of Africa, most of the crew were afflicted with scurvy…As they sailed farther up the east coast of Africa, they met local traders, who traded them fresh oranges, and within 6 days of eating them, the crew recovered.”
da Gama thought healthy air was the cure, but “the crew were convinced that the oranges that they had eaten were powerful curatives, because they particularly asked for them the next time scurvy appeared….
“When Commodore George Anson set out with 8 ships and 1,854 sailors to the South Seas in 1740, he returned in 1744 with only 1 ship and 188 men; the great majority of the rest died of scurvy.”
from: A brief history of vitamin C and its deficiency, scurvy by Harri Hemilä