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Amino Acids. The building blocks that make up proteins. Humans need 20 different amino acids to function properly. Some are made by the body. Others, called essential amino acids, must be obtained from foods.

Antioxidant. Substances, like vitamins A, C, E, and beta-carotene, that protect your body from the damage of oxidation caused by free radicals.

Botanicals. Substances obtained from plants and used in food supplements, personal care products, or pharmaceuticals. Other names include “herbal medicine” and “plant medicine.”

Daily Value. Found on food and drink nutrition labels, this number tells you the percentage of the recommended dietary allowance provided by one serving of the food or drink in question.

Fat Soluble. The fat-soluble vitamins are A, D, E, and K. Your body stores excess fat-soluble vitamins in your liver and body fat, then uses them as needed. Ingesting more fat-soluble vitamins than you need can be toxic, causing side-effects like nausea, vomiting, and liver and heart problems.

Fortify. To increase a food or drink's nutritional value by adding vitamins, minerals, or other substances. For example, milk is fortified with vitamins A and D.

Free Radicals. An atom or molecule with at least one unpaired electron, making it unstable and reactive. When free radicals react with certain chemicals in the body, they may interfere with the ability of cells to function normally. Antioxidants can stabilize free radicals.  

Herb. Herbs are plants used as flavorings and spices in cooking, but herbs can also be used as supplements for health or medicinal reasons.

Megadose. Supplements that provide more than 100% of the daily value of the body's required vitamins and minerals.

Micronutrients. The name given to vitamins and minerals because your body needs them in small amounts. Micronutrients are vital to your body's ability to process the "macronutrients:" fats, proteins, and carbohydrates. Examples are chromium, zinc, and selenium.

Minerals. Nutrients found in the earth or water and absorbed by plants and animals for proper nutrition. Minerals are the main component of teeth and bones, and help build cells and support nerve impulses, among other things. Examples include calcium and magnesium.

Multivitamin. A pill, beverage, or other substance containing more than one vitamin.

Oxidation. A chemical reaction in which oxygen combines with a substance, changing or destroying its normal function. Oxidation can damage cell membranes and interfere with a cell's regulatory systems, but it is also part of our normal-functioning immune system.

Phytochemicals. Compounds found in fruits, vegetables, and other plants that can be health-protecting. Phytochemicals (sometimes called phytonutrients) include beta-carotene, lycopene, and resveratrol.

Prenatal Vitamins. Specially formulated multivitamins that ensure a pregnant woman gets enough essential micronutrients. Prenatal supplements generally contain more folic acid, iron, and calcium than standard adult supplements.

Recommended Dietary Allowance (RDA). The amount of nutrients needed daily to prevent the development of disease in most people. An example is vitamin C; the RDA is 70 milligrams, below which, for most people, there is the risk of developing scurvy.

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