Vitamins are organic food substances found only in living things, i.e. plants and animals. They are essential for our bodies to function properly, for growth, energy and for our general well-being. With very few exceptions the human body cannot manufacture or synthesize vitamins. They must be supplied in our diet or in man-made dietary supplements. Some people believe that vitamins can replace food, but that is incorrect. In fact, vitamins cannot be assimilated without also ingesting food. That is why it is best to take them with a meal. They are found in very small quantities in food; certain health specialists recommend taking vitamin supplements to increase the supplies in food, while others insist that a well-balanced diet provides all the vitamins that an ordinary person needs. With such vitamins, there may be a danger of taking too much, but in the case of most vitamins, the greatest harm comes from not receiving enough. Vitamin deficiencies can be the cause of rickets, pellagra, and other diseases that have plagued the poor in the Western world and the third world in the past and in the present.
However, they do not in themselves provide energy, and thus vitamins alone do not qualify as a form of nutrition.Organisms require vitamins only in very small amounts: the total amount of vitamin mass a person needs in one day, for instance, is only about 0.5 g. Yet vitamins are absolutely essential to the maintenance of health and for disease prevention.
Numerous vitamin groups are necessary for the nutritional needs of humans, and though only small amounts of each are required to achieve their purpose, without them life could not be maintained. Some vitamins, including A, D, E, and K, are fat-soluble, meaning that they are found in fattier foods and in body fat. Thus, they can be stored in the body; for this reason, it is not necessary to include them in the diet every day. In fact, it could be dangerous to do so, since it is possible that they would build up to toxic levels in the tissues. Other vitamins, the most notable of which are vitamin C and the many vitamins in what is known as the "B complex," are water-soluble. They are found in the watery parts of food and body tissue, and because they are excreted regularly in the urine, they cannot be stored by the body. Instead, they must be consumed on a daily basis. This difference in solubility is extremely important to the way the vitamins function within an organism and in the ways and amounts in which they are consumed.
Vitamins originally were classified in terms of their solubility in water or in fat, and these distinctions remain important for the reasons outlined above. Today, vitamins are known primarily by letters of the alphabet, a fact that goes back to a naming system developed as more and more vitamins were discovered in the early years of the twentieth century.As scientists detected the existence of more vitamins, or what they thought were vitamins, they gave them successive letters of the alphabet: A, B, C, and so on.
In modern life we are used to being told that fat is bad for us, but, that is not necessarily so. Fat is not inherently bad for people; in fact, a certain amount in the diet is essential. The problem with fat today is the type of fat that people consume. There is a big difference between the healthy, natural, unsaturated fats one might find,for example in fresh salmon, and the highly processed and saturated fats in a bag of potato chips. Such fat is extremely harmful, because the body is not able to process it; even so, a certain amount of natural fat in the diet can be highly beneficial. This is true in large part because fat can serve as a medium for the fat-soluble vitamins A, D, E, and K, which are deposited in the body's fat...
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