People long suspected that certain foods would prevent or cure illnesses; but proof was lacking until modern times. During the 14th and 15th centuries, sailors at sea died by the hundreds from the vitamin C-deficiency disease scurvy, and ships often returned to port with only a third of their crew. In 1601, however, when the English East India Company sent out its first ship, most of the seamen survived the arduous voyage because the captain had seen to it that each of them received three teaspoons of lemon juice daily. Although many sea captains probably knew that citrus cured scurvy, they did not know why and thus went on experimenting with cheaper and less perishable foods while lives continued to be lost. Finally, at the end of the 18th century, the British Admiralty made it a rule that lemon juice be given to sailors each day, starting with the fifth or sixth week at sea, and mortality rates dropped dramatically. When limes from the West Indies were substituted for lemons in the mid-19th century, British sailors acquired their famous nickname “limeys.” However, people still did not know that it was the vitamin C content of lemons (or limes) that prevented or cured scurvy; indeed, no one had ever heard of vitamins.
It wasn’t until 1913 that two American biochemists actually isolated the first vitamin. In the course of experimenting with the effects of a specific type of diet on young rats, E.V. McCollum and his associate Marguerite Davis discovered a substance they called simply “fat-soluble A.” Just a year earlier, across the Atlantic in England, Casimir Funk, a Polish biochemist who became an American citizen, had partially isolated one of the B vitamins. For this substance he coined the word vitamine (for vital amine), amine being the group of chemical compounds that Funk believed essential for the prevention or cure of such diseases as scurvy, beriberi, pellagra, and rickets. Although Funk was proved wrong about the chemical compounds (some subsequently isolated vitamins contained no amine), the word caught on and continued to be used, but without the e.
In 1922 McCollum identified vitamin D, and from that time on discoveries came in rapid succession. By 1948 scientists had identified the 13 vitamins now considered essential to good human health (see chart on pages 36-37). This was great progress indeed, considering the special challenges of vitamin research: because the amounts of vitamins in thebody are so small, they are extremely difficult to detect and track.
The discovery of vitamins was linked at the very beginning to the prevention of disease. In fact, shortly after the turn of the century, Funk and the Englishman Frederick G. Hopkins enunciated the theory of vitamin deficiency disease. And scientists quickly accepted the idea that certain substances in food could prevent disease, adding to the knowledge, learned a century earlier, that diseases were caused by food-borne germs or by infections. Vitamin deficiency diseases are now almost entirely wiped out in this country. Nonetheless, health scientists continue to stress the preventive role vitamins play in warding off deficiency diseases.