A nutrient is a chemical that an organism needs tae live an grow or a substance uised in an organism's metabolism which must be taken in frae its environment. Thay are uised tae big an repair tissues, regulate body processes an are convertit tae an uised as energy. Methods for nutrient intake vary, wi ainimals an protists consumin fuids that are digestit bi an internal digestive seestem, but maist plants ingest nutrients directly frae the soil through thair ruits or frae the atmosphere.
Organic nutrients include carbohydrates, fats, proteins (or thair biggin blocks, amino acids), an vitamins. Inorganic chemical compounds such as dietary minerals, watter, an oxygen mey an aa be considered nutrients. A nutrient is said tae be "essential" if it must be obtained frae an external soorce, either acause the organism cannae synthesize it or produces insufficient quantities. Nutrients needit in very smaa amoonts are micronutrients an those that are needit in larger quantities are cried macronutrients. The effects o nutrients are dose-dependent an shortages are cried deficiencies.
See healthy diet for mair information on the role o nutrients in human nutreetion.
References[eedit | eedit soorce]
- Whitney, Elanor and Sharon Rolfes. 2005. Understanding Nutrition, 10th edition, p 6. Thomson-Wadsworth.
- FRANCES SIZER; ELLIE WHITNEY (12 November 2007). NUTRITION: CONCEPTS AND CONTROVERSIES. Cengage Learning. pp. 26–. ISBN 978-0-495-39065-7. Retrieved 12 October 2010.
- Audrey H. Ensminger (1994). Foods & nutrition encyclopedia. CRC Press. pp. 527–. ISBN 978-0-8493-8980-1. Retrieved 12 October 2010.