Vitamins
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[ Missing Letters of the Vitamins | Beriberi, A Mysterious Disease | How the Word Vitamin was Formed | Antivitamins | Our Vitamin Needs | Food Sources of Vitamins ]
You may have taken vitamin pills and known that oranges are a rich source of vitamin C. Besides vitamin C, there are many other vitamins, such as vitamin A, B, C, D, E. So, what are vitamins?
All proteins are similar to each other in their chemical structure and so are all carbohydrates. Vitamins, on the other hand, are a group of organic substances quite unrelated to each other in their chemical structure. Some common features shared by all vitamins are that they are not digested or broken down for energy, they are not built into body structures, they are essential in very small quantities for normal health, and that they are needed for chemical reactions in the cells, working in association with enzymes. Some vitamins and enzyme partners help to form body parts such as bones, body tissues, blood cells, and the body genes. Some vitamins help in forming the body’s defense against disease-causing bacteria and viruses.
Each vitamin has a chemical name and a letter. For example, vitamin C is also known as ascorbic acid. Fat-soluble vitamins include A, D, E and K. There are nine other vitamins which are water soluble: vitamin C and eight B vitamins: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine(B6), folacin, cobalamin (B12) and biotin.
Missing Letters of the Vitamins
A... B... C... D... E... K... wait! where’s F, G, H and I? And why are there so many Bs? The first vitamins were discovered and named in alphabetical order, until a Danish researcher discovered and named vitamin K. He named it after the Danish word for clotting, Koagulation, because vitamin K helps the blood to clot. Meanwhile scientists had found that what they thought was a single vitamin B was really a group of vitamins that are usually found together in the same foods. So numbers were attached to the B. By this time, the last B vitamins were discovered and the system of letter naming was out of style. Thus, some of the B vitamins are called only by their chemical names.
Beriberi, A Mysterious Disease
Beriberi is a disease that affects the heart and nervous system and can cause paralysis and death. (Its name means "I can’t, I can’t!", a good way to describe how tired and weak people feel when they are suffering from the disease.)
In 1884 the director of the Naval Medical Bureau, Baron Kanehiro Takaki, sent two ships on a 287-day voyage during which the men on one ship are served a diet of meat, cooked fish, and vegetables, while the men on the other ship get the usual Japanese diet of polished white rice and raw fish. Some 160 men out of 360 come down with beriberi on the second ship and 75 died, while on the first ship nobody died. The 160 cases of beriberi were found to occur only among men who refused to accept the prescribed diet. Takaki ordered Western-style rations to be served aboard all Japanese naval vessels.
What was missing in the diet of the men on the second ship was actually thiamin (vitamin B1). Beriberi can be treated by adding thiamin to the diet.
How the Word Vitamin was Formed
In 1911, a Polish chemist Casimir Funk ,discovered which nutrient was missing in white rice. With just a milligram of this substance, he cured a pigeon paralyzed by beriberi. The mystery nutrient was a chemical in the amine family. (Members of the amine family contain nitrogen.) Funk suggested that there was a whole group of chemicals in foods that prevented various diseases when they were eaten in small amounts. He named them vitamines (Vita means "life", so "vitamines" are amines needed for life.) In 1926, the substance discovered by Casimir Funk was identified as thiamin. But as more "vitamines" were identified, most of them were not amines. Hence,scientists dropped the "e" and called them vitamins.
Antivitamins can be found in some foods, and they prevent vitamins from working in the body. Some kinds of fish contain the enzyme thiaminase which breaks down thiamin into forms the body can’t use. Heat destroys the enzyme, so when fish is cooked, its thiamin can be used by the body. But when people eat raw fish, the thiamin can’t be used.
The total amount of vitamins that we need is very small, only milligrams or micrograms of each one per day. An ounce of vitamin B12 would provide the daily requirement for more than nine million people! All the vitamins a person needs each day add up to about an eighth of a teaspoon.
Plants can make these vitamins in their leaves, but animals have to take them in ready-made, either from plants or from other animals. We will develop vitamin-deficiency diseases due to low levels of any vitamins in our diet. Fortunately, most diseases can be cured in their early stages by adding the vitamin to the diet. So, choose a wide variety of food to have enough of the vitamins.
| Food Sources of Vitamins By eating a variety of food, we get the
vitamins we need. Different foods contain vitamins.
Fruits contain Vitamin C. Vitamin K can be found in leafy
vegetables and many other foods. Animal foods contain
Vitamin A and D. Vitamin B is present in vegetables and
meat. Do you know that vitamins can
help to keep you young? Refer to this site: Back to Top |
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This page has been authored for participation in
the 1997 Thinkquest Competition.
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