Scurvy is a strange disease caused by inadequate amounts of vitamin C (ascorbic acid) in the body. Vitamin C is a reducing agent that plays a large role in the hydroxylation of the proline and lysine amino acids in the collagen protein. When there isn't enough vitamin C in the body, the proline and lysine used to form collagen will experience underhydroxylation, which results in the resulting protein structure, collagen, having a lower than usual melting point.
Why is this a big deal? Because collagen is a bonding material that helps hold the body's cells together. When the collagen isn't strong, the body isn't strong. It could be thought of as a cement holding two tires together, representing cells. If the cement is very weak, it will be easy to crack the cement and separate the tires, whereas a strong cement will be much more difficult to break.
Symptoms of scurvy include muscular weakness, pain in the joints, bruises, raised red marks near hair follicles, and pain while chewing. The bruises and red marks are caused by hemorrhaging of cells in the body. The pain while chewing is caused by loosening of the teeth and tooth structure.
James Lind discovered that citrus fruits contained some ingredient that rehabilitated patients with scurvy and convinced the Royal Navy to provide citric juices in daily rations to prevent scurvy from occurring in sailors. Sailors were most susceptible to scurvy since fruit was rarely taken on naval voyages and, if it was taken, rotted quickly. The citric component of daily rations earned the sailors the nickname "limeys", which is still used today. In 1932, Waugh and King, two researchers at the University of Pittsburgh, successfully isolated ascorbic acid and synthesized it, leading the way to vitamin C mass manufacture.
Scurvy is a very rare condition in modern times, since food processors regularly fortify their products with vitamin C and bottles of vitamin C tablets can be purchased at any pharmacy. People today also have greater access to citric fruit at low prices, due to efficient transportation. However, some cases are still found, mainly in people living in poverty, who are unable to buy citrus fruit.