Passage 2

Vitamins are organic compounds necessary in small amounts in the diet for the normal growth and maintenance of life of animals, including man.  

They do not provide energy, __1__do they construct or build any part of the body. They are needed for   2   foods into energy and body maintenance. There are thirteen or more of them, and if   3   is missing a deficiency disease becomes   4  .

Vitamins are similar because they are made of the same elements — usually carbon, hydrogen, oxygen, and   5   nitrogen. They are different   6   their elements are arranged differently, and each vitamin   7   one or more specific functions in the body.

 __8__ enough vitamins is essential to life, although the body has no nutritional use for __9_  vitamins. Many people,   10  , believe in being on the “safe side” and thus take extra vitamins. However, a well-balanced diet will usually meet all the body’s vitamin needs.

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