Estimating the bioavailability factors needed for setting dietary reference values

Susan J Fairweather-Tait, Rachel Collings

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Estimated average requirements for micronutrients are central to deriving Dietary Reference Values. These are used for nutrition policies and programs, and also for regulatory and labeling purposes, and are traditionally devised to cover the needs of virtually all individuals in any population group. In order to estimate the average requirement, an appropriate endpoint (biomarker) is selected which describes the relationship between dietary intake and health. However, for some micronutrients, such as zinc, there are no good biomarkers, and for others, such as iron, the intake-status relationship is confounded by variations in absorption. Average requirements for these nutrients are derived using a factorial approach in which physiological needs for tissue growth and maintenance and endogenous losses are estimated, and the total converted to a dietary requirement by taking into account the overall absorption from the diet; i. e. multiplying the requirement by a bioavailability factor. The latter can be determined using algorithms, or estimates from absorption studies, some of which are described in this short review paper.
Original languageEnglish
Pages (from-to)249-256
Number of pages8
JournalInternational Journal for Vitamin and Nutrition Research
Issue number4-5
Publication statusPublished - Oct 2010


  • Biological Availability
  • Biological Markers
  • Diet
  • Humans
  • Intestinal Absorption
  • Iron, Dietary
  • Micronutrients
  • Nutrition Policy
  • Nutritional Requirements
  • Reference Values
  • Zinc

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