To take or not to take, that is the question often asked about vitamin supplements. Some experts suggest that a balanced diet provides all the vitamins we need, while others claim that a daily multivitamin pill provides nutritional insurance. Then there are those who allege that vitamins can both prevent or cure a variety of diseases while others point to studies that imply vitamins are linked with greater morbidity. Too much confusion to clear up in one short lesson. But the confusion about the term “vitamin” can be addressed. Indeed, it is a misnomer. Vitamins are “vital,” but they are not necessarily amines.
“Vitamin” derives from the Latin “vita” for life and “amine,” the name for a family of nitrogen containing organic compounds. But as it turns out, not all vitamins are amines. The very first one, isolated from rice hulls by biochemist Casimir Funk in 1912 was indeed an amine and was given the name “thiamine.” Funk thought that there likely were other amines essential to life that had to be supplied by the diet and suggested the term “vitamine” be used to describe them. He was right about the existence of other “vitamines,” but when it turned out that they were not all amines, the “e” was dropped from the name.
Funk’s discovery takes us back to the late nineteenth century when the mechanized rice mill was introduced in Asia . It produced attractive white rice, but it also produced a new disease that came to be called “beriberi”. In the native language of Sri Lanka, beriberi means “weakness”, and describes a condition of progressive muscular degeneration, heart irregularities and emaciation. Kanehiro Takaki, a Japanese medical officer, studied the high incidence of the disease among sailors in the Japanese navy from 1878-1883 and discovered 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.
About 15 years later a Dutch physician in the East Indies , Christiaan Eijkman, 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, but he was wrong. And that’s when Casimir Funk entered the picture. The Polish-born biochemist determined that it wasn’t something that was present in white rice that was the problem, it was something that was absent, namely the outer coating, the rice “hulls.” Funk managed to show that an extract of rice hulls prevented beriberi and introduced the term “vitamine” for substances in food that could prevent specific diseases.
A short time later, 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. These “vitamins” had a common function. They formed part of the various enzyme systems needed to metabolize proteins, carbohydrates and fats. Some of the compounds in Funk’s water extract eventually turned out to offer no protection against any specific disease and their names had to be removed from the list of vitamins. As other water soluble substances which were required by the body were discovered, they were added to the B vitamin list.
Other vitamins were subsequently identified and given the designations C, 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 successfully kept alive for many years through total parenteral nutrition ( TPN ) which involves using an intravenous formula that incorporates the known vitamins.
And what then about those daily vitamins that are so heavily advertised? They don’t kill and they don’t cure. But they may fill in some nutritional gaps in a less than ideal diet. And nobody really knows what an ideal diet is.
