Flashcards in 1) DRI Deck (108)
What are DRIs?
New references for planning and assessing nutrient intakes
When were DRIs developed? Who developed DRIs?
- In 1997
- Joint collaboration between Health & Welfare Canada, USDA, NIH, and the US Academy of Sciences (FNB of IOM)
What was the issue with the Recommended Daily Allowance (old RDA)?
- Issued a false impression that the recommendation must be met every single day, and that a state of deficiency would occur if not
- The body stores certain nutrients, which may compensate if an individual does not consume an adequate amount in a day
What do the DRIs expand and replace?
- The former RDAs in the US (published since 1941)
- The Recommended Nutrient Intakes (RNIs) in Canada (published since 1938)
What was the RNI previously referred as?
The Recommended Daily Nutrient Intake (RDNI), which was changed in 1983 to reflect an average intake over time
What are the components of the committees regulating DRIs?
- Standing Committee on the Scientific Evaluation of DRIs
- Nutrient Expert Panels
- Upper Reference Level Subcommittee
- Uses of DRIs Subcommittee
What are the functions of the Standing Committee on the Scientific Evaluation of DRIs?
- Oversees the five-year process, coordinating the recommendations from nutrient panels and subcommittees
- Submits the report for review to the National Research Council
What is the major function of Nutrient Expert Panels?
Develop a series of DRI reports, in conjunction with the two subcommittes
What five factors do Nutrient Expert Panels analyze?
1) The role the nutrient plays in each life stage
2) The role the nutrient plays in the development of chronic disease
3) The indicator of adequacy of the nutrient
4) The EAR of the nutrient for each life stage
5) The interpretation of the current intake data of North American population groups
How many Nutrient Expert Panels are there?
What is the mandate of Nutrient Expert Panels?
To determine nutrient requirements for the prevention of nutrient deficiencies AND to consider the levels of intake needed to prevent chronic disease
Why is the Upper Reference Level Subcommittee particularly important in recent years?
Since supplementation and food fortification are now a major source of nutrition
What two factors does the Upper Reference Level Subcommittee analyze?
1) Hazard identification to determine the highest intake of a nutrient without adverse effects
2) Assessment of the actual exposure of the population to determine to what extent there is a risk for toxicity
What is the major function of the Uses of DRIs Subcommittee?
- Deals with appropriate (or inappropriate) applications for reference intakes
- Overall, they help the population interpret and apply the information
What is a nutrient?
Substance that is necessary for proper biological and physiological function, without which deficiency occurs
What are other food components?
Foods that are not considered nutrients (e.g. phytochemicals)
What is the difficulty with applying recommendations for other food components?
The fact that there are no nutrient composition tables
What are the four nutrient-based references of DRIs?
What do DRIs focus on?
Chronic disease prevention
How is chronic disease prevention taken further from DRIs? (4)
1) Looking at RDA values for micronutrients
2) Recommendations are set for deficiency, disease prevention, and chronic disease prevention
3) UL is established due to the common use of nutritional supplements
4) Non-essential food components are being considered for chronic disease prevention
What population groups do RDAs not apply to?
- They do not apply to individuals with specific illnesses
- RDAs are generated as recommendations for a healthy population
What percentage of the population is met with an EAR + 1 standard deviation? What about an EAR + 2 standard deviations?
- EAR: 50%
- EAR + 1SD: 84%
- EAR + 2SD: 97.5%
Which DRI is used for groups? Which DRI is used for individuals?
- EAR: groups
- RDA: individuals
How is the EAR determined?
The intake of the nutrient that provides adequate intake for 50% of individuals in a life stage and gender group
What factors are added to the intake of a nutrient that provides adequate intake for 50% of individuals to produce the EAR?
- Safety factor for optimal tissue stores
- Factor that accounts for accounts for additional needs for growth (e.g. pregnancy, lactation, childhood)
- Factor for bioavailability (if the nutrient has less than 100% absorption)
In addition to usual intake distribution of healthy people, valid studies must be considered concerning what? (3)
- Deficiency states
- Balance studies
- Animal research
What are the four conceptual similarities between DRIs and the former RDAs and RNIs?
They must account for:
1) Individual variability in a population
3) Sex and age differences
4) Physiological state (e.g. pregnancy and lactation)
What curve would a population with a highly variable requirement produce? How would the RDA differ from the EAR?
- A flatter curve with a high standard deviation
- The RDA would be much higher than the EAR
What are the four criteria of adequacy?
1) Biomarkers of exposure
2) Biomarkers of mechanisms or functional outcome
3) Biomarkers of effect
4) Biomarkers of a clinical outcome