Sailors, Scurvy, and the Missing Vitamin
Sailing ships once spent months at sea with no way to keep fresh food. Sailors ate hard biscuit, salted meat, and dried peas. Over a long voyage, many crew members developed a disease called scurvy. They grew weak and tired, and their gums became sore. On some voyages, scurvy was a more serious danger to the crew than storms.
For centuries, nobody understood the cause. People blamed bad air, laziness, or spoiled food. Yet sailors and ship doctors noticed that crews recovered when they reached land and ate fresh fruit and vegetables. In the 1700s, a Scottish naval doctor named James Lind ran a careful comparison aboard a ship. He divided sick sailors into small groups and gave each group a different remedy. The group that received oranges and lemons recovered fastest.
Lind's results were slow to be accepted, but eventually the British navy began to supply citrus juice to its crews.
The full explanation came much later. Scientists discovered that the body needs a nutrient called vitamin C to build and repair connective tissue, the material that holds skin, gums, and blood vessels together. Humans cannot make vitamin C themselves, so it must come from food. Citrus fruits, peppers, strawberries, and potatoes are good sources. A crew eating only preserved food was missing it almost entirely. Today, scurvy is rare because fresh food is easy to ship and store.