dietary reference values Flashcards
how can we tell if people manage sufficient amounts of nutrients to maintain adequate health
by comparing their intakes with recommendations
who were DRVs published by in 1991
DoH
whys it important to set standards for nutrient intake
To prevent deficiency symptoms.
To optimise body stores of a nutrient. E.g. to optimise vit D stores
To optimise a biochemical or physiological function. E.g. need sufficient amount of nutrient if its maybe a cofactor for an enzyme to work
To minimise risk factor for some chronic disease. E.g. reducing sat fatty acid intake reduces levels of cholesterol so reduce CHD
To minimise incidence of a disease. E.g. increase fibre intake reduce risk of colorectal cancer
what was the name of the USAs first version od dietary standards produced in 1943 by the national research council
the Recommended Dietary Allowances (RDAs).
what did the RDAs in 1943 aim to provide
a yardstick against which diets or food supplies could be assessed to determine their adequacy.
how many nutrients did the RDAs provide info on in 1943
10 nutrients
Modern day equivalents provide info on about 30 or more nutrients.
when were the UK Recommended Daily Intakes (RDIs) and the UK Recommended Daily Amounts (RDAs) introduced
1969 UK Recommended Daily Intakes (RDIs)
1979 UK Recommended Daily Amounts (RDAs)
what happened to the name of the RDAs in 1991
Nomenclature changed – ‘recommended’ led many to believe it represented min desirable intake for health.
so name changed to UK Dietary Reference Values (DRVs) published.
what did the DRVs apply to
Apply to the range of intakes based on an assessment of the distribution of requirements for each nutrient.
who did the DRVs apply to
heathy people
Not appropriate for those with disease or metabolic abnormalities.
DRVs for 1 nutrient presuppose what
that requirements for energy & all other nutrients are met.
e.g. prot & vit A – If vit A req met but not prot, insufficient RBP to transport vit A. – nutrients work together
why do you need to use caution when assessing diets of individuals with the DRVs
so making sure that you don’t use any strong statements
what are uses of DRVs
Assessing diets of individuals - Use caution!
Assessing diets of groups of people and populations.
For providing guidance on composition of meals and diets.
Food labelling e,g, reference intake on food packaging are based on DRVs
name the 3 levels that the UK 1991 COMA (Committee on Medical Aspects of Food Policy) panel set for DRVs
Estimated Average Requirement (EAR)
Lower Reference Nutrient Intake (LRNI)
Reference Nutrient Intake (RNI)
what is the EAR
Estimated Average Requirement (EAR)
Average requirement that Will meet the needs of 50% of the whole population.
half od pop will usually need > EAR. half will need less.
what is the LRNI
Lower Reference Nutrient Intake (LRNI)
Will meet the needs of 2.5% of the whole population.
Situated 2 SD below EAR.
LRNI equivalent to 1969 RDI.
In many countries LRNI is only figure used.
what is the RNI
Will meet the needs of 97.5% of the whole population.
Situated 2 SD above EAR.
RNI includes margin of safety – individuals with intake just below RNI may have sufficient intake.
if nutrient intake is greater then RNI then the individuals intake can be classed as
almost certainly adequate
if individuals intake is <EAR and < RNI then their intake can be classes as
likley to be adequate
If intake is > LRNI and < EAR then the individuals intake can be classed as
likely to be inadequate
If intake is < LRNI then individuals intake can be classed as
almost certainly inadequate for most individuals
why can we say someone is deficient if they’re nutrient intake is below the RNI and even well below the EAR
as it may be sufficient to their needs
If mean for group is around the RNI most subjects should be what
okay
if mean for a group is around the EAR then subjects might be what
all subjects might be OK but more likely some will not be.
