Research and Discovery: The Amazingly Young History of Vitamins
Vitamins are vital nutrients that our bodies cannot produce on their own. They must therefore be consumed regularly with food. This is common knowledge these days. But while vitamin deficiency diseases such as scurvy were known as early as 2000 BC, vitamins were not discovered until the beginning of the 20th century. A real boom in vitamin research quickly developed. From a medical point of view, 13 of the 20 known vitamins are now considered essential for humans. Let's take a look back at the exciting history of vitamins.
The discovery of vitamins is closely linked to the fight against deficiency diseases.
The Discovery of Vitamins
The foundation for the discovery of vitamins was laid by the doctor and chemist Nikolai Lunin. In 1881, he was researching artificial nutrition for mice as part of his dissertation. At that time, fat, carbohydrates, proteins and salts were the only necessary nutritional components. Lunin artificially isolated fat, lactose, casein and salts from milk and fed this mixture to a group of mice. A second group, however, received fresh milk. After a while, the first group died. Lunin concluded that milk must contain small amounts of another vital substance.
Spread of Beri-Beri through Polished Rice
The Dutch tropical doctor Christiaan Eijkman made further progress. He was sent to Indonesia in 1886 to investigate the cause of the widespread disease beri-beri. Signs of beri-beri include nerve inflammation and the resulting so-called sheep gait, skin inflammation and edema. Eijkman suspected a bacterial pathogen as the cause. In 1897, he discovered that chickens that ate husked rice were also affected by beri-beri, while chickens that ate unhusked rice were spared. Feeding rice bran to chickens even made the disease go away. He concluded that the rice husk must contain a substance that renders the bacteria or the toxins they produce harmless. His assistant Gerrit Grijns pursued the theory that the polished rice lacked a substance that protects the nervous system.
Food is more than just an energy source
This work gave rise to a new wave of vitamin research. Since 1906, the English physiologist Frederick Gowland Hopkins has been of the opinion that, in addition to the well-known nutritional components of protein, carbohydrates, fat and minerals, other vital factors must be included. In a paper published in 1912, he called these accessory nutritional factors. His work also dealt with the nutrition of rats using artificial milk building blocks. In the course of his research, Hopkins also succeeded in detecting vitamins A and B in milk. Hopkins and Eijkman were jointly awarded the Nobel Prize in 1929 for their discoveries.
The term vitamin is born
However, the term vitamins for accessory nutritional factors goes back to Casimir Funk. He was also inspired by Eijkmans' work and put forward the theory that a lack of certain substances can trigger various diseases. In 1912, he isolated a nitrogen-containing compound from rice bran, i.e. the fine silvery membranes that lie between the rice grain and the outer shell and are no longer present in polished rice. He believed it to be an amine, i.e. a derivative of ammonia. He subsequently coined the term "vital(vita=life) amine" for this and other substances. In fact, his discovery was not an amine, but nicotinic acid, also known as niacin or vitamin B3. Niacin is also ineffective against beriberi, but it is effective against another deficiency disease called pellagra. The term "vitamin", however, became a successful model. Independently of this, the chemist Suzuki Umetaro, who also investigated the ingredients of rice bran, succeeded in isolating the actual beri-beri factor in 1910. He called the substance "arberic acid" and later oryzanin. Today this substance is known as thiamine or vitamin B1.
isolation of other vitamins
This led to a real race to discover and isolate other vitamins. In 1926, thiamine was first isolated in crystalline form from rice bran. By 1936, all 13 essential vitamins had been isolated in their pure form. This was often closely linked to the treatment of diseases caused by their deficiency. For example, it had been known since the 16th century that scurvy can be prevented by eating certain foods, particularly citrus fruits. In 1927, this made it possible to isolate vitamin C from cabbage, peppers, and the adrenal glands. The healing effect of cod liver oil on rickets had been known since 1807. In 1923, the effect of sunlight as a healing factor was also discovered for the first time. Finally, in 1927, Adolf Windaus was able to extract vitamin D2 (ergocalciferol) from ergosterol through photochemical synthesis. By extracting the isolated vitamins, many deficiency diseases could be treated much more easily.
Today, even the very youngest children know how important vitamins are for their health – even if they often prefer to eat chips and chocolate.
The essential vitamins
As early as 1913, Elmer McCollum introduced capital letters as trivial names for vitamins. The first eleven vitamins were initially numbered from A to K. For some substances, it was decided that they should not be classified as vitamins. As a result, there is now a gap between E and K. Other substances with similar effects were grouped together. For example, vitamin H (biotin) became vitamin B7. This results in the list of 13 vitamins that are now considered essential.
- Vitamin A (retinol)
- Vitamin B1 (thiamine)
- Vitamin B2 (riboflavin)
- Vitamin B3 (niacin)
- vitamin B5 (pantothenic acid)
- Vitamin B6 (pyridoxine)
- Vitamin B7 (biotin)
- vitamin B9 (folic acid)
- Vitamin B12 (cobalamin)
- Vitamin C (ascorbic acid)
- Vitamin D (calciferol)
- Vitamin E (tocopherol)
- Vitamin K (phylloquinone)
Vitamins are also divided into water-soluble and fat-soluble. Vitamins A, D, E and K are fat-soluble. This means that they can be better absorbed by the body in meals that contain a little fat. The human body is also able to store these vitamins in the liver and in fat and connective tissue. This means that overdosing on vitamins in this group can have harmful effects. This is not known for the group of water-soluble vitamins (with the exception of pyridoxine). In this case, excess vitamins are simply flushed out via the kidneys.
What is the current situation regarding vitamin supply?
Due to the knowledge gained since the beginning of the 20th century, deficiency diseases such as rickets, scurvy and beriberi have virtually died out in industrialized countries. A normal mixed diet with several portions of fruit and vegetables is sufficient to provide an adequate supply of all vitamins, especially since many foods, from cornflakes to gummy bears, are also enriched with vitamins. Certain lifestyle habits and some illnesses can, however, make an additional supply of vitamins necessary. Smokers, for example, have a need for up to 40 percent more vitamin C. Vegans must also take in B12, as this is only found in animal products. Pregnant and breastfeeding women are recommended to take in additional supplies of vitamins A, C, B1, B2, B6 and folic acid. Since appetite decreases with age and smaller portions are consumed, an additional supply of vitamins can also be useful here. However, the intake of vitamin supplements, especially fat-soluble vitamins, should always be discussed with a doctor.
Current state of research
Vitamins have always been a controversial research topic. While some see them as the solution to most health problems, others think the "vitamin hype" is overrated or even harmful. And so, since the beginning of vitamin research, there has been another study that claims the opposite for almost every opinion and study. Not all of the physiological processes that take place within us have been deciphered, and the influence that other food components might have still needs to be researched. It has also been shown that every person functions differently when it comes to nutrition. So it is basically impossible to make general statements. Except that the topic of vitamins and nutrition will probably remain an exciting research topic for some time to come.
