Implementing food-based dietary guidelines for - United Nations ...

Nutrient intake values (NIVs): A recommended
terminology and framework for the derivation of
values
Janet C. King, Hester H. Vorster, and Daniel G. Tome
Abstract
Although most countries and regions around the world
set recommended nutrient intake values for their populations,
there is no standardized terminology or framework
for establishing these standards. Different terms used
for various components of a set of dietary standards are
described in this paper and a common set of terminology
is proposed. The recommended terminology suggests that
the set of values be called nutrient intake values (NIVs)
and that the set be composed of three different values.
The average nutrient requirement (ANR) reflects the
median requirement for a nutrient in a specific population.
The individual nutrient level (INL x ) is the recommended
level of nutrient intake for all healthy people in
the population, which is set at a certain level x above the
mean requirement. For example, a value set at 2 standard
deviations above the mean requirement would cover
the needs of 98% of the population and would be INL 98 .
The third component of the NIVs is an upper nutrient
level (UNL), which is the highest level of daily nutrient
intake that is likely to pose no risk of adverse health
effects for almost all individuals in a specified life-stage
group. The proposed framework for deriving a set of
NIVs is based on a statistical approach for determining
the midpoint of a distribution of requirements for a set
of nutrients in a population (the ANR), the standard
deviation of the requirements, and an individual nutrient
level that assures health at some point above the
mean, e.g., 2 standard deviations. Ideally, a second set
of distributions of risk of excessive intakes is used as the
basis for a UNL.
Janet C. King is affiliated with the Children’s Hospital
Oakland Research Institute and the University of California at
Berkeley and Davis, California, USA; Hester H. Vorster is affiliated
with North-West University (Potchefstroom Campus),
Potchefstroom, South Africa; Daniel G. Tome is affiliated with
the Institut National Agronomique Paris-Grignon, Paris.
Please direct queries to the corresponding author: Janet C.
King, Children’s Hospital Oakland Research Institute, 5700
Martin Luther King Jr. Way, Oakland, CA 94609, USA; e-mail:
jking@chori.org.
S16
Key words: Nutrient requirements, nutrient recommendations,
recommended dietary allowances, recommended
nutrient intakes
Introduction
Most countries or regions around the world recommend
nutrient intake values for their populations.
These recommendations serve as a basis for national
or regional nutrition policies, nutritional educational
programs, and food regulations and action programs.
Traditionally, these standards have been set at a level
that would cover the requirements of practically all
healthy persons in the population. As new knowledge
of human nutrient requirements becomes available, the
standards need to undergo a reassessment and revision
as appropriate. Most countries or regions review the
status of knowledge and update their nutrient intake
values about every 5 to 10 years.
The amounts of nutrient intakes recommended
vary considerably from country to country. Also, the
terms used to describe the intake values differ. For
example, some countries recommend a single value
that serves as a recommended intake for all members
of a population subgroup, whereas other countries
recommend four different values: a lower reference
intake, an average requirement, a recommended intake
for nearly all members of a population group, and an
upper tolerable level or limit. There is no standardized,
commonly agreed-upon terminology for these terms.
Furthermore, there is no standard method or approach
for deriving these different nutrient intake values.
In this paper, we will review the different terms
and definitions used to describe a set of dietary recommendations
from different countries and regions
around the world. We will then propose a set of terms
and definitions for harmonizing nutrient intake values
worldwide. Finally, we will suggest a theoretical framework
for deriving specific nutrient intake values.
Throughout this paper, a set of dietary intake recommendations
derived from primary research data is
Food and Nutrition Bulletin, vol. 28, no. 1 (supplement) © 2007, The United Nations University.