Vitamins are substances that must be included in the diet to maintain health and prevent certain deficiency diseases. They cannot be synthesized by the body in sufficient amounts. [1] In 1912, biochemist Casimir Funk obtained a water extract of rice polishings that contained what would later be identified as thiamine. Thiamine was indeed an amine, and was later named using the prefix “thia” meaning “sulfur-containing.” Funk thought that there likely were other amines essential to life that were to be found in 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, leading Takaki to conclude that protein prevented the disease. He was wrong.
About 15 years later, physician Christiaan Eijkman, who had been sent by the Dutch government to the East Indies to study beriberi, made a serendipitous discovery. He noted that chickens in his laboratory developed symptoms of beriberi after being fed leftover rice from military rations. Curiously, the symptoms disappeared when a new cook refused to feed military rice to civilian chickens, and rice was purchased from another source. The difference was that military rice was “polished” and had the “hull,” the outside coating, removed. Eijkman surmised that polished rice lacked a dietary component found in unpolished rice, and that beriberi was caused by depriving the body of this component, which he called "the anti-beriberi factor."
It is at this point that Casimir Funk entered the picture. Realizing that the difference between polished and unpolished rice was the presence of the hull in the unpolished rice, he searched there for Eijkman’s anti-beriberi factor and found that a water extract successfully treated beriberi. The active ingredient would turn out to be “thiamine.” Since grain processing removes thiamine, flour and many cereals today are enriched with thiamine. Funk went on to propose that other diseases such as scurvy, pellagra, and rickets may also be the result of a nutritional deficiency that can be prevented or cured by restoring a missing nutrient. It was Eijkman who was awarded the 1929 Nobel Prize in Physiology or Medicine for his discovery that rice hull contains some factor that prevents beriberi, but it is Funk who deserves credit for the creation of the vitamin concept.
A year after Funk identified an amine as Eijkman’s “anti-beriberi factor,” Elmer 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. 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" since 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.
Some supplement manufacturers are trying to capitalize on vitamin mania and are offering products like “vitamin B17,” extracted from apricot pits, which they claim treats cancer. There is no such vitamin. Neither is there any “vitamin O” that is claimed to contain “stabilized oxygen” to boost the blood’s oxygen content. The O might as well stand for "outrageous scam."
NOTE:
[1] Some vitamins can be synthesized by the body, but not necessarily in amounts sufficient to meet our physiological needs. For example, vitamin D can be produced in the skin following exposure to ultraviolet light, and niacin can be synthesized from the amino acid tryptophan. These are the exceptions rather than the rule.
# Reprinted with permission. Dr. Schwarcz’s original article can be found on the OSS website
May be lightly edited for clarity and accuracy
Joe Schwarcz
Dr. Joe Schwarcz is Director of McGill University's “Office for Science and Society” which has the mission of separating sense from nonsense. He is well known for his informative and entertaining public lectures on topics ranging from the chemistry of food to the connection between the body and the mind.
