title: Growth and micronutrient needs of adolescents.
abstract: OBJECTIVE
  This paper focuses on micronutrients in relation to needs throughout adolescence, a period which involved growth and development that occur through a complex interaction of genetic instructions, hormones and environmental influences, many of them of dietary origin. In the context of micronutrient 'needs' it is of special importance to differentiate between the 'nutritional needs' and 'metabolic needs'. Two main questions arise in relation to the micronutrient needs: (1) why are micronutrients necessary? and (2) how are their needs assessed?
  
  
  RESULTS
  The 'necessary' amount will differ according to the objectives pursued: (a) to achieve a satisfactory rate of growth and development; and (b) to maintain 'optimal health'. The assessment of micronutrient needs and status has proved to be difficult, but when elucidating and establishing them, it is imperative to arrive at the estimates in the light of their interdependent role in metabolism and functions. The knowledge of micronutrient metabolic needs can be approached through epidemiological observations, bioavailability studies and clinical trials. However, there is a nearly total absence of reports on the particular metabolic and dietary needs of adolescents.
  
  
  CONCLUSIONS
  Thus more studies are required in relation to the effect of features associated with adolescence on 'needs', evaluating their impact on bioavailability and turnover (storage and losses), and the interactions among micronutrients in the assessment of metabolic and nutritional needs. Another aim should be to establish static and functional indexes, reference values and cut-off points in adolescence, to be used in clinical and epidemiological studies. Future studies should focus on needs to determine those required to maintain 'optimal functions' and regarding the potential prevention of chronic adult diseases.
authors.affiliation: Servicio de Nutrición, Unidad de Vitaminas, Clínica Puerta de Hierro, Madrid, Spain. bego.olmedilla@nutr.cph.es
authors.forename: B
authors.initials: B
authors.lastname: Olmedilla
authors.forename: F
authors.initials: F
authors.lastname: Granado
mesh_terms: D000293:Adolescent; D017195:Adolescent Nutritional Physiological Phenomena; D005260:Female; D006128:Growth / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D018977:Micronutrients / Q000378:metabolism; D009751:Nutritional Requirements; D014131:Trace Elements / Q000008:administration & dosage
chemical_list: D018977:Micronutrients; D014131:Trace Elements