Objective: This paper focuses on micronutrients in relation to needs throug
hout adolescence, a period which involved growth and development that occur
through a complex interaction of genetic instructions, hormones and enviro
nmental influences, many of them of dietary origin. In the context of micro
nutrient 'needs' it is of special importance to differentiate between the '
nutritional needs' and 'metabolic needs'. Two main questions arise in relat
ion 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 pur
sued: (a) to achieve of growth and development; and (b) to maintain 'optima
l health'. The assesment 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 metab
olism and functions. The knowledge of micronutrient metabolic needs call be
approached through epidemiological observations, bioavailability studies a
nd clinical trials. However, there is a nearly total absence of reports on
the particular metabolic and dietary needs of adolescents.
Conclusion: Thus more studies are required in relation to the effect of fea
tures associated with adolescence on 'needs', evaluating their impact on bi
oavailablility and turnover (storage and losses), and the interactions amon
g micronutrients in the assessment of metabolic and nutritional needs. Anot
her aim should be to establish static and functional indexes, reference val
ues and cut-off points in adolescence, to be used in clinical and epidemiol
ogical studies. Future studies should focus on needs to determine those req
uired to maintain 'optimal functions' and regarding the potential preventio
n of chronic adult diseases.