Vitamins and Minerals
Structure and Functions (Magill’s Medical Guide, Sixth Edition)
Vitamins are organic compounds (that is, compounds made up of carbon, oxygen, nitrogen, sulfur, or hydrogen) that are constituents of food and that are crucial to the maintenance of life and good health. They make possible the production of energy and the formation of coherent body tissues from the macronutrients normally consumed in a regular diet. They are, among other things, coenzymes that serve as oxidizing, reducing, and transfer chemicals at the active sites of enzymes. Vitamins are part of the one hundred or so organic compounds that are of the proper size and stability to be absorbed from the digestive tract into the bloodstream without digestion or breakdown. Nevertheless, they are not produced in the body in amounts large enough to keep a person healthy—because they have always been available in food, there was probably no need for the human metabolism to produce them. Vitamins are synthesized by plants, and therefore plants constitute the principal natural source of these compounds.
Vitamins are divided into two main groups: the water-soluble and the fat-soluble vitamins. Structural differences account for the two types of solubility. Fat-soluble vitamins (such as vitamins A, D, E, and K) consist mainly of hydrocarbon groupings (nonpolar hydrocarbon chains and rings compatible with nonpolar oil and fat) and are structurally similar to fats, whereas water-soluble vitamins have polar hydroxyl (-OH) and...
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Vitamin deficiencies are not common in the United States and other Western countries. A well-balanced diet provides ample vitamins of all kinds. Megadoses of vitamins can create harmful effects, however, as a toxic dose exists for many vitamins. For example, vitamin A, when taken in excess, can cause headache, nausea, vomiting, fatigue, swelling, hemorrhage, pain in the arms and legs, and birth defects. An acute deficiency of the vitamin, however, can impair vision and eventually cause blindness. Consequently, there must be a balance in vitamin intake. This balance can be achieved by following the recommended daily (or dietary) allowances (RDAs).
In the United States, the Food and Nutrition Board of the National Academy of Sciences and the National Research Council determined the daily needs for some vitamins and minerals. The Food and Drug Administration (FDA) made these findings the basis for its list of RDAs. These allowances are presented in units of grams or milligrams, and these amounts are determined using international units of biological activity. (Some vitamins come in several forms, all of which are physiologically equivalent.) RDAs do not cover every single vitamin and mineral needed for good health, nor do they cover the more extreme nutritional requirements that result from illness or unusual genetic makeup. They just serve as general guidelines for healthy individuals. For some substances lacking specific...
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
Vitamin deficiency diseases such as scurvy, beriberi, and pellagra have plagued the world at least since the existence of written records. The concept of a vitamin or “accessory growth factor” was developed in the early part of the twentieth century. In 1912, Casimir Funk, a Polish biochemist, isolated a dietary growth factor from the outer covering of rice grains and found that, when added to the food of those who had beriberi, it cured the disease. The factor was an organic compound called an amine (that is, a compound containing nitrogen combined with carbon and hydrogen). Funk coined the term “vitamine” (meaning “life-giving amine”) for the compound, which is now called thiamin or vitamin B1. In the next five decades, there was an exciting era of the isolation, identification, and synthesis of vitamins. It was soon found that these compounds were not all amines, and the term was changed to “vitamins.” As more information on the structure of vitamins was obtained, names changed from general ones (such as vitamin C) to more specific ones (such as ascorbic acid). These discoveries led to the availability of inexpensive synthetic vitamins and to a dramatic reduction in overt vitamin deficiency disease.
Small amounts of vitamins are essential for good health, but the benefits of taking megadoses of certain vitamins to prevent or cure certain ailments are often debated. Even so, there is evidence that...
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
Balch, James F., and Phyllis A. Balch. Prescription for Nutritional Healing: A Practical A to Z Reference to Drug-Free Remedies Using Vitamins, Minerals, Herbs, and Food Supplements. 4th rev. ed. Garden City Park, N.Y.: Avery, 2008. A guide to nutritional, herbal, and complementary therapies. Includes the latest research and theories on treatment of aging, HIV, and a host of other subjects.
Duyff, Roberta Larson. American Dietetic Association Complete Food and Nutrition Guide. 3d ed. Hoboken, N.J.: John Wiley & Sons, 2007. The official recommendations of this organization.
Lieberman, Shari, and Nancy Bruning. Real Vitamin and Mineral Book. 4th ed. New York: Avery, 2007. Discusses what vitamin and mineral supplements are and why they are needed to protect against disease and aid in mental and physical well-being. Chapters provide factual information on common vitamins, minerals, and other supplements and give recommendations for use with daily nutrition.
Murray, Michael. The Pill Book Guide to Natural Medicines: Vitamins, Minerals, Nutritional Supplements, Herbs, and Other Natural Products. New York: Bantam, 2002. An excellent guide that answers questions about the effectiveness and safety of more than two hundred popular natural remedies. Examines what the product is for and how it works; rates products for safety and effectiveness; discusses possible side effects...
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Vitamins and Minerals (Science Experiments)
Fats and water
Experiment 2 Hard Water: Do different water sources have varying mineral content?
VitaminsOrganic substances that are essential for people's good health; most of them are not manufactured in the body. and are substances that are essential for people to grow, develop, and remain healthy. Vitamins are organicMade of, or coming from, living matter., meaning that they contain carbon and come from living organisms. Minerals are , meaning that they do not contain carbon or come from living organisms. Except for two vitamins, humans cannot make any of their own vitamins and minerals. People must get these nutrients from foods. Diseases characterized by lack of nutrients are called deficiency diseasesA disease marked by a lack of an essential nutrient in the diet..
There are hundreds of vital functions that require proper vitamins and minerals. Maintaining strong bones and muscles, ensuring good vision, healing wounds, providing energy, and fighting infections are a few examples of how the body uses these substances. For years researchers focused their work on determining the amount of each...
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