Lessons Learned and New Challenges: Observations from a User of DRIs

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Lessons Learned and New Challenges Observations
from a User of DRIs

• Susan Whiting
• University of Saskatchewan

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Outline

• Overcoming user problems with existing DRIs
• How to assess using AIs
• Interpretation of UL
• Assessment and planning for Groups
• Looking towards a better DRI
• Setting recommendations using chronic disease
  endpoints

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Overcoming user problems with existing DRIs How
to assess with AIs

• AIs are estimates of RDAs not EARs
• Indicate lack of evidence for setting
  requirements
• Assessment of groups use below EAR
• Assessment of Individuals use ltEAR gtEAR and
  ltRDA, gtRDA
• Suggested that we estimate probabilities for AIs

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Overcoming user problems with existing DRIs How
to assess with AIs

• Suzanne Murphy suggested that we estimate
  probabilities for AIs
• Calcium and vitamin D important nutrients

• Calcium Intake Probability of Inadequacy
• 0-300 mg Probability 100
• 301-600 mg Probability 75
• 601-900 mg Probability 50
• 901-1,200 mg Probability 25
• gt 1,200 Probability 0

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Overcoming user problems with existing DRIs
Interpretation of ULs

• 1. Remembering that UL are by definition safe
  with probability of risk of adverse effects 0
• 2. Understanding heterogeneity of UL derivations
• Not all endpoints were equal
• E.g., Flushing for niacin vs. Liver damage for
  vit A
• 3. The Uncertainly Factor (UF) could bring a UL
  down to a very conservative value.

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ULs

• UL NOEAL/UF or LOAEL/UF
• Intended use of UF convert LOEAL to NOAEL
• Uncertainty factor (UF) subjective value
• E.g., setting UL for vitamin A for young women
  (teratogenic effects 3000 µg) same as for
  men/older women (liver toxicity) by manipulating
  the UF

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DRI Diagram Showing risk of inadequacy curve
steeper than risk of excess
The Development of the DRIs 1994-2004 Lessons
Learned and New Challenges. NAP 2008
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Overcoming user problems with existing DRIs
Assessment and planning for Groups

• Questions that have been raised
• How large is a group?
• 2. To assess a group, should a small group
  actually be treated as individuals
• 3. How should dietary guidelines be set?
• -Canada keep Prevalence of Inadequacy low
• - USA ensure each individual meets RDA

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Looking towards a better DRI

• Setting recommendations using chronic disease
  endpoints

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No DRIs
A few DRIs
Most DRIs
The Development of the DRIs 1994-2004 Lessons
Learned and New Challenges. NAP 2008
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Prevalence of Inadequacy Food Secure (FS) and
Food insecure (FI)
CCHS 2004 data. Kirkpatrick Tarasuk J Nutr 2008