Vitamins are essential for human health. Lack of vitamins in our diet can lead to many diseases such as scurvy and rickets. Isaac Asimov’s “what we found out about vitamins”, describes the experiments that led to the discovery of vitamins. The following are few snapshots of the book that can be used to elicit student’s thinking on how science concepts evolve with time.
Life on the open seas:
On long voyages, sailors ate dry bread and smoked meats. However, sailors often became sick, their gums started to bleed, their muscles hurt and finally many died due to the disease called “scurvy”.
Is there any relation between diet and health?
Scurvy also struck in prisons, and hospitals, wherever the diet was dull. An Austrian doctor, J. G. H. Kramer, noticed that the common soldiers had only bread and beans to eat got sick, but the officers also ate fruit and green vegetables never got. He thought,
“Is there any relation between diet and health?”
What could be the right food to prevent scurvy?
In 1747, a Scottish doctor, James Lind, decided that scurvy could be stopped by the right diet. He added certain foods to the diet of sailors who had scurvy, such as cider to the regular diet, in others vinegar, in still others various fruit juices (orange, lemons or limes). Can you think which one among these could prevent scurvy? He found that the quickest recovery came when juice from citrus fruits was added to the diet.
In 1794, the use of limes on British warships became so common that British sailors were called “limeys”. Finally, from 1795 on, scurvy was wiped out in the British navy.
100 years later, Japanese army faced a similar challenge, but with different disease.
Onset of beriberi:
In 1853, Japanese sailors often fell sick, they became very weak, and their arms and legs were almost paralyzed. Finally, they die. And they found this new illness differs from scurvy, affecting the legs particularly, even when vegetables and fruits are part of the sailor’s diet.
How “B”arley beats “B”eriberi?
The admiral in charge ,K. Takake, knew that the British had beaten the scurvy problem by changing the diet of their sailors and knew that British sailors never got beriberi. He therefore compared the diet of British and Japanese sailors:
Japanese sailors: Vegetables, fish, and white rice.
British sailors: Did not eat rice, but ate other grains such as barley.
Can you imagine how he would have changed the diet of Japanese sailors? Yes, Takake made the Japanese sailors eat barley along with their rice. The result was the disappearance of beriberi from the Japanese navy.
Is there “something else” in the food besides carbohydrates, proteins, lipids and minerals?
Jean Dumas (1870), tried to prepare an artificial food containing carbohydrates, lipids, proteins, minerals and water and hoping it would substitute for the milk for the needed babies. Do you think it worked well? It did not work. Through this, Dumas suggested that there might be something in food besides these that was essential for life and health.
Can microbe be a causative agent for beriberi?
Christian Eijkman (1858-1930), found a flock of chickens showing the symptoms of beriberi. He tested them for microorganisms that he believed were causing the disease. Do you think whether he could find a causative microbe for beriberi? He had no success. Then, he discovered that the old cook was feeding them with unpolished rice, whereas the new cook was feeding polished rice, which resulted in beriberi. When he fed them with unpolished rice, they recovered. Was the polished rice poisonous? Or did the polished rice lack something? Was the magic present in the husk?
Warrior against Beriberi
In 1906, Frederick Hopkins, found the Anti-beriberi substance had a three-atom combination. What probably could these atoms be? Any substance that contained this group was called an “amine”. Oh! Amines… the combination of two hydrogen atoms and one nitrogen…!!So, are these vitamins Nitrogen source?
What might be the other purposes vitamin can serve in the body??..
Funk said that there was a whole series of amines that were needed in small quantities for life and health. Funk called them all “vitamines”- “vita” means “life” in Latin. The name, invented by Funk, became “vitamin” and we have used that name ever since. Can we think of calling them the vital amines too??...
Term: Term 1