Author
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Hunt, Curtiss |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 7/15/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Problems encountered in establishing the appropriate range of dietary intakes of a given nutrient include insufficient characterization of either the physiological requirement or intoxication threshold. The problem is compounded by the obligation to build in a margin of safety into the Recommended Daily Allowances (RDAs) which raises concern that actual requirements are overestimated. Also, overlap sometimes occurs between nutrient intakes considered necessary for chronic disease prevention and those intakes that induce direct or indirect pharmacologic and toxic effects in certain subpopulations. Identifying the causes of variation in "endpoint" variables is critical in establishing either nutrient requirements or intoxication thresholds. The reality that RDAs rely heavily on data obtained from complex, chaotic (not random) systems, that current indeterminacies in the data sets are permanent, not temporary, and that there is often remarkable uncertainty or imprecision in available experimental observations argues for consideration of mathematical methods that account for graded degrees of abnormality (fuzziness) in the data sets or that embed, not externalize randomness, and thus characterize nonlinear systems. Fuzzy set theory allows data without sharp cutoff points between normality and abnormality to be incorporated into the decision-making model. Nonlinear dynamic modeling helps describe various biological phenomena that exhibit chaotic oscillation. Application of fuzzy set theory and nonlinear dynamic theory may be particularly useful in defining nutrient requirements and intoxication. |
