1 - DRIs Flashcards
(48 cards)
expand RDA by current and past definitions. when were RDAs first published?
current: Recommended Dietary Allowances
past: Recommended Daily Allowances
published: 1941
expand RNI. when first published?
Recommended Nutrient Intakes
published: 1938
why did the D change from daily to dietary in RDA?
daily is a misnomer bc in reality, your body can use stores of nutrients. the specified amount is averaged out over days/months.
what largely determines a vitamin’s turnover rate in the body?
water/fat solubility
when were RNIs, safe levels of intake, and RDAs last reviewed?
RNI: 1990
Safe Level of Intake: 1985
RDA: 1995
why are upper reference levels made?
came about as a result of toxicity associated with recent fortification/supplementation
How many nutrient-based references are there for DRIs? what are they?
four: EAR, RDA, AI, UL
what is EAR?
Estimated Average requirement (from which RDA is determined)
what is RDA?
recommended Dietary allowance, which replaces the former RDA and RNI
what is AI?
Adequate Intake (alternative reference when EAR and consequently RDA are not available)
what is UL?
Tolerable Upper Intake Level
True or false: a nutrient without an EAR has an RDA
false
what percentage of people will receive sufficient nutrition by consuming an EAR?
50%
what percentage of people will receive sufficient nutrition by consuming an RDA?
97.5%
how is an RDA determined?
2 standard deviations above an EAR
true or false: not all nutrients have an RDA
true
RDAs are determined on experimentation on a (compromised/healthy) population
healthy - RDAs are usually deficient for sick people
RDAs are based on estimation of a minimal requirement to achieve some ______ _____
measurable outcome
what are some limitations of RDAs?
since it’s based on young/healthy ppl, it poses risk to elderly which have different needs
extrapolation downward for childhood is also a limitation, potentially becoming deficient due to their growth needs
what is a balance study?
finds point of input that leads equal output
what kind of studies to RDAs consider in addition to healthy people?
- deficiency states
- balance studies
- animal research
what must an RDA account for?
- individual variability in a population
- bioavailability
- sex and age differences
- physiological state
what’s coefficient of variation?
CV = sd/mean
what is a limitation of Canada’s RDAs regarding bioavailability?
they are based on the fact that animal proteins are a normal part of the diet. it does not account well for vegetarian diets. on this bases, the values of absorption need to be much higher for vegetarians or vegans, esp because of phytates, tannins, & oxalates which are more prevalent here.