The term “food accessory factor” was coined by British biochemist Frederick Gowland Hopkins in 1906 after he demonstrated that rats fed a diet of proteins, fats, carbohydrates and minerals failed to grow. Although these substances were known to be the major components of the food supply, they were not sufficient to maintain health. Something was missing. When Hopkins supplemented the diet with minute amounts of milk, the rats thrived. There was something in the milk in addition to the usual nutrients, some “food accessory factor” that was necessary for growth.Â
Hopkins was not the first to make such an observation. Between 1878 and 1883, Kanehiro Takaki, a Japanese medical officer, had studied the high incidence of “beriberi” among sailors in the Japanese navy. This was a terrible disease characterized by muscular degeneration, heart irregularities and emaciation. The term had been coined from an expression in the native language of Sri Lanka, meaning “I cannot, I cannot,” referring to the progressive lack of mobility experienced by those afflicted. Takaki found that on a ship where the diet was mostly polished rice, among 276 men, 169 cases of beriberi developed, and 25 men died during a nine-month period. On another ship, there were no deaths and only 14 cases of the disease. The difference was that the men on the second ship were given more meat, milk and vegetables. Takaki thought this had something to do with the protein content of the diet, but he was wrong.Â
About 15 years later, Christiaan Eijkman a Dutch physician working in Java, noted that chickens fed mostly polished rice also contracted beriberi but recovered when fed rice polishings. He thought that the starch in the polished rice was toxic to the nerves, and that the bran contained an anti-toxin, but he was also wrong. Casimir Funk, a Polish biochemist who had come to America, read an article by Eijkman in which he described that people eating brown rice were less vulnerable to beriberi than those who ate only the fully milled product. Funk attempted to isolate the substance responsible and in 1912 finally succeeded. The compound turned out to belong to a family of molecules called amines, and Funk, thinking these were vital to life, introduced the term “vitamine.”
Funk suggested that diseases such as rickets, pellagra and scurvy were also vitamine deficiency conditions, an idea that had also occurred to Dutch researcher Gerrit Grijns who had followed up on the work of Eijkman. This turned out to be correct, but the deficiency factors were not all amines, and the ending “e” from “vitamin” was dropped to avoid confusion. In 1929, Hopkins and Eijkman shared the Nobel Prize in Physiology and Medicine for their work on vitamins, but Grijns and Funk were passed over. Funk, perhaps justifiably, protested that the Nobel committee had given the prize to Hopkins for “his discovery of the growth-stimulating vitamins.” Hopkins himself, however, never claimed to be the discoverer of vitamins. Indeed, there was no single discoverer, many scientists contributed to the knowledge we now have about vitamins.
In 1913, E.V. McCollum and Marguerite Davis at the University of Wisconsin discovered that rats given lard as their only source of fat failed to grow and developed eye problems. When butterfat or an ether extract of egg yolk was added to the diet, growth resumed, and the eye condition was corrected. McCollum suggested that whatever was present in the ether extract be called fat soluble “A,” and that the water extract Funk had used to prevent beriberi, be called water-soluble factor “B.” When the water-soluble extract was found to be a mixture of compounds, its components were given designations with numerical subscripts. The specific anti-beriberi factor was eventually called vitamin B1 or thiamine.
Vitamin B3, or niacin, was destined to join the club when in 1914 Dr. Joseph Goldberger, working for the United States Public Health Service, solved the puzzle of pellagra that was epidemic in the southern states, especially in cotton growing areas. Described as the disease of the four D’s, diarrhea, dermatitis, dementia and death, the disease was thought to be connected to cotton either in the form of some germ or toxin in the plant. Goldberger demonstrated that the disease was actually due to a diet that consisted mostly of corn and that it could be cured by adding fresh vegetables, milk and eggs. Finally, in 1937 Conrad Elvejhem identified niacin as the nutrient absent in corn that was needed to prevent pellagra.
Perhaps the most famous vitamin, vitamin C, was identified in 1932 by Albert Szent Gyorgyi as the substance that was needed in the diet to prevent scurvy. He had extracted the compound from paprika and suggested it be named ascorbic acid. A year later, British chemist Walter Haworth determined the compound’s molecular structure. Long before the identification of ascorbic acid, Scottish physician James Lind in his “Treatise on Scurvy,” published in 1753, had described experiments demonstrating that scurvy could be prevented by consuming citrus fruits. This led to sailors on British ships being supplied with lime juice.
Other vitamins were subsequently identified and given the designations D and E in order of their discovery. Vitamin K was so called because its discoverer, the Danish biochemist Henrik Dam, proposed the term "Koagulations Vitamin" because it promoted blood coagulation. Are there still unrecognized vitamins? Not likely. Patients have now been kept alive for many years through total parenteral nutrition (TPN), which involves using an intravenous formula that incorporates the known vitamins. However, ongoing research aims to investigate whether vitamins may have some benefit beyond preventing nutritional deficiency diseases. There have been suggestions that vitamin C can prevent the common cold, vitamin E may reduce the risk of cardiovascular disease, and vitamin D is a virtual cure-all. None of these claims are backed by compelling evidence but that has not prevented vitamin supplements from blossoming into a multi-billion-dollar industry.
