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Hello. My name's Susan
Fairweather-Tait.
I'm a professor of
human nutrition in
the Norwich Medical School at
the University of East
Anglia in the UK,
and I'm going to be
talking to you about
dietary reference values
for minerals and vitamins.
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Dietary reference values
is an umbrella term
that guides professionals
on the amount of
nutrients needed by
population groups.
They are quantitative
reference values
for nutritional intakes
derived for different
population groups,
and they're based
on health criteria.
There are some
alternative names.
So in the USA,
they use the term dietary
reference intakes, DRIs,
and they used to use
the term recommended
daily allowances, RDAs.
CODEX, for labeling
purposes, used
the term nutrient
reference values, NRVs.
So DRVs are intended
for healthy people.
People with diseases may have
different nutrient requirements
so they're not
appropriate for them,
and they're not nutrient goals
or recommendations
for individuals.
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If we look at the
distribution curve for
nutrient requirements
in a population,
you can see there's quite
a wide range of variation.
So most people
have a requirement
which is close to the average.
But there are a few
number of people who have
very high or very low
requirements for a nutrient.
We assume that the nutrient
requirements are
normally distributed.
If we do that, then the
average requirement is
the requirement that meets
the needs of 50%
of the population.
If we look at
the population reference
intake or the RDA/RNI,
this is the level which meets
the requirements of
97.5% of the population.
A vast majority of the
population will have
enough if the level is
set at a high level.
The population reference
intake, or the RNI,
is set at two
standard deviations
above the estimated
average requirement.
The terminology of
dietary reference values
