QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Carriquiry, A. L. Articles by Camaño-Garcia, G. Search for Related Content PubMed PubMed Citation Articles by Carriquiry, A. L. Articles by Camaño-Garcia, G.

---

Supplement: Understanding Tolerable Upper Intake Levels

Evaluation of Dietary Intake Data Using the Tolerable Upper Intake Levels^1–3,

Department of Statistics, Iowa State University, Ames, IA 50011

⁴ To whom correspondence should be addressed. E-mail: alicia{at}iastate.edu.

We discuss the problem of assessing nutrient intake relative to the tolerable upper intake levels (UL) for the nutrient proposed by the Institute of Medicine and focus on 2 important topics: the estimation of usual nutrient intake distributions and the extent to which intakes above the UL can be considered risky. With the information that is currently available for most nutrients, it is not possible to estimate the proportion of individuals in a group with intakes that place them at risk. This is because the shape of the dose-response curve needed to carry out a risk assessment is unknown for most nutrients. Thus, intakes above UL cannot be declared to be unsafe. Intakes below the UL, however, are likely to pose no risk to individuals in the group. Because determining the proportion of individuals with intakes below the UL requires estimation of an upper-tail percentile of the intake distribution, the use of 1-d intake data or otherwise unadjusted intake data are likely to lead to severely biased estimates. It is important to remove within-individual variance in intakes from daily intakes so that the tails of the usual intake distribution are accurately estimated. Underreporting of the amount of nutrients consumed will tend to shift the estimated usual nutrient intake distribution downwards. In this case, the true proportion of individuals with intakes below the UL is likely to be overestimated.

KEY WORDS: • upper level intakes • usual intake distributions • total nutrient intake • day-to-day variability in intake • under-reporting of calories