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这是一篇关于维生素及其功能的文章。

carbon

hydrogen

oxygen


nitrogen

well-balanced
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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, nor do they construct or build any part of the body. They are needed for transforming foods into energy and body maintenance. There are thirteen or more of them, and if any is missing a deficiency disease becomes apparent. Vitamins are similar because they are made of the same elements -- usually carbon, hydrogen, oxygen, and sometimes nitrogen. They are different in that their elements are arranged differently, and each vitamin performs one or more specific functions in the body. Getting enough vitamins is essential to life, although the body has no nutritional use for excess vitamins. Many people, nevertheless, 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.
维生素是有机化合物，饮食中必须含有​少量维生素以维持动物(包括人)的生存和正常生长。 它们不提供能量，也不构成身体的任何一部分，它们的任务是把食物转变成能量和维持身体健康。至少有 13 种维生素，若缺其中一种，缺乏症疾病便明显可见。 各种维生素都很相似，因为它们由同样的元素构成，一般是碳、氢、氧，有时还有氮。它们的不同之处在于每种维生素内部的元素排列不同，并且每种维生素在人体内都有一种或多种特殊作用。 虽然维生素对人体并无什么营养上的用处，但吸收足够的维生素是必要的。尽管如此，有些人出于保险的想法，还是摄入过量的维生素。不过，均衡的饮食一般能够完全满足身体对维生素的需求。