Inorganic. Compounds that do not contain carbon, such as minerals and water. “Inorganic” is not synonymous with “synthetic,” as it is sometimes erroneously suggested.
Macronutrients. Vitamins or minerals that are needed in daily amounts of hundreds of milligrams.
Micronutrients. Vitamins or minerals that are needed in daily amounts up to a few milligrams.
Enzymes. These protein molecules, produced by cells, act as catalysts in breaking down carbohydrates, protein, and fats during digestion so that these products can be absorbed; the enzymes remain unchanged in the process. Within all living body cells there are also enzymes that catalyze body metabolism.
Coenzymes or cofactors. Nonprotein substances necessary for the function of some enzymes.
Absorption. A process by which nutrients move from the digestive tract (stomach, small and large intestines) into the bloodstream to be utilized by the body.
Metabolism. A process by which digested nutrients are converted into energy and building blocks for vital processes or body cells.
Nucleic acids. The collective name for the DNA and RNA molecules found in the nucleus of every cell; they are involved in reproduction and cell division.
Hormones. These are substances created in the body and secreted by the endocrine or ductless glands; they regulate enzyme activity of the digestive system and much other cell activity. Hormones are often unfairly blamed for a person being overweight.
Dietary Allowances are consumed daily. Adeficiency in a fat-soluble vitamin may take many more months to develop than a deficiency of a water-soluble vitamin.