Vitamins

/>
A - Levels text

Vitamins
Vitamins are a group of organic substances required in our diets in small amounts for growth and nutrition. They are usually found in foodstuffs or taken as supplements. Yet vitamins probably present a wider gap between myth and reality in the laymans understanding than almost any other area of our diet. Most people have recognition that Vitamin C prevents scurvy, that Vitamin A is found in fish liver oils, or that Vitamin D is found in dairy products; many people believe that Vitamin E preserves youth and prevents sterility or that Vitamin C can present colds and cancer. Beyond this, however, there is still considerable ignorance and widespread myth. The reality behind the common practice of taking vitamin supplements is less dramatic, although vitamins do represent an important component of the necessary human diet.
The word vitamin was formed from the Latin word "vita" ("life") and the Greek word "amine", because 19th century scientists believed that they were formed only from amino acids. Amino acids are the twenty essential code elements which arrange themselves in varied sequences or chains to form complex proteins, the basic foodstuff of life. These organic acids (containing the essential ingredient NH2), in conjunction with the nucleic acids (DNA material being composed of the four bases adenine, guanine thymine and cytosine), "translate" the genetic instructions from the DNA of the chromosome to the RNA transcript, and in turn transfer these instructions from the transcript to proteins. If proteins are the building blocks of life, then amino acids are the building blocks of proteins. Plant cells form amino acids from the compounds which the plant draws up from the grou