Livro DRI 2006 (Micronutrientes)

Livro DRI 2006 (Micronutrientes)


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as the median
of the current intake distribution, plus (or minus) the amount that the distribu-
tion needs to shift to make it the target usual intake distribution.
In the current example, although the baseline intakes at the 10th percen-
tile and the median differ among the three surveys, the estimates of the medians
TABLE 8 Identification of the Target Median Intakea of Vitamin B6 to Obtain
a 10 Percent Prevalence of Inadequacy in Older Women
Intake Difference Target
at 10th (EAR \u2013 intake Median Median
EAR Percentile at 10th Intake Intake
Study (mg/day) (mg/day) percentile) (mg/day) (mg/day)
Survey A 1.3 1.04 0.26 1.53 1.79
Survey B 1.3 0.88 0.42 1.41 1.83
Survey C 1.3 0.6 0.7 1.0 1.70
a The target median intake is estimated by adding the difference between the Estimated Average
Requirement (EAR) and the intake at the acceptable prevalence of inadequacy (in this case, 10 percent) to
the observed median intake.
Copyright © National Academy of Sciences. All rights reserved.
Dietary Reference Intakes: The Essential Guide to Nutrient Requirements
http://www.nap.edu/catalog/11537.html
PART I: APPLYING THE DIETARY REFERENCE INTAKES 65
of the target usual intake distributions are quite similar, as shown in Table 8.
Assuming that a 10 percent prevalence of intakes below the EAR was consid-
ered acceptable, a median intake for vitamin B
6
 of 1.7 to 1.8 mg/day would be
the planning goal. Accordingly, the menu would need to be planned so that
vitamin B
6 
intakes would be at this level.
Estimates of target nutrient intakes must be converted to estimates of foods
to purchase, offer, and serve that will result in the usual intake distributions
meeting the intake goals. This is not an easy task. Meals with an average nutri-
ent content equal to the median of the target usual nutrient intake distribution
may not meet the planning goals, as individuals in a group tend to consume less
than what is offered and served to them. Thus, the planner might aim for a
menu that offers a choice of meals with a nutrient content range that includes,
or even exceeds, the median of the target usual nutrient intake distribution.
STEP 4. ASSESS IMPLEMENTATION OF THE PLAN
Ideally, after the menu had been planned and implemented, a survey would be
conducted to assess intakes and determine whether the planning goal had been
attained. This would then be used as the basis for further planning.
KEY POINTS FOR WORKING WITH GROUPS
ASSESSING NUTRIENT INTAKES
3 The goal of assessing nutrient intakes of groups is to determine
the prevalence of inadequate (or excessive) nutrient intakes
within a particular group of individuals.
3 Assessment of groups should always be performed using
intakes that have been adjusted to represent a usual intake
distribution.
3 The probability approach and the EAR cut-point method are
two statistical methods of determining the prevalence of
inadequacy in a group. The EAR cut-point method is a simpler
method derived from the probability approach.
3 For nutrients in which it is appropriate to do so, the EAR can be
used as part of the EAR cut-point method to determine the
prevalence of nutrient inadequacy within a group. Otherwise,
the probability approach can be used.
3 The AI has limited application in assessing a group\u2019s nutrient
intakes. For nutrients with an appropriately estimated AI,
groups with mean or median intakes at or above the AI can
generally be assumed to have a low prevalence of inadequate
intakes.
Copyright © National Academy of Sciences. All rights reserved.
Dietary Reference Intakes: The Essential Guide to Nutrient Requirements
http://www.nap.edu/catalog/11537.html
66 DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS
3 The UL can be used to estimate the proportion of a group at
potential risk of adverse effects from excessive nutrient
intakes.
3 The RDA should not be used in the assessment of a group\u2019s
nutrient intakes. Comparing mean or median intake with the
RDA is inappropriate.
3 To assess the energy adequacy of an individual or group diet,
information other than self-reported intakes should be used
because underreporting of energy intake is a serious and
pervasive problem. Body weight for height, BMI, or other
anthropometric measures are suitable for use in assessing
long-term energy intake.
PLANNING NUTRIENT INTAKES
3 The goal of planning nutrient intakes for groups is to achieve
usual intakes that meet the requirements of most individuals,
but that are not excessive.
3 The DRIs present an approach to planning that involves
consideration of the entire distribution of usual nutrient intakes
within a group.
3 The basic steps in planning for groups are as follows: First the
practitioner decides on an acceptable prevalence of
inadequacy. The distribution of usual intakes in the group must
then be estimated using the distribution of reported or
observed intakes. Finally, a target usual intake distribution is
determined by positioning the distribution of usual intakes
relative to the EAR to achieve the desired prevalence of
inadequacy.
3 For nutrients with an EAR, the planning goal is to aim for an
acceptably low prevalence of intakes below the EAR.
3 The RDA is not recommended for use when planning nutrient
intakes of groups.
3 For nutrients with an AI, this value is used as the target for the
mean or median intake when planning for groups.
3 For nutrients with a UL, the planning goal is to achieve an
acceptably low prevalence of intakes above the UL.
3 When planning a group\u2019s energy intake, the goal is for the
group\u2019s mean intake to equal the EER.
Copyright © National Academy of Sciences. All rights reserved.
Dietary Reference Intakes: The Essential Guide to Nutrient Requirements
http://www.nap.edu/catalog/11537.html
PART I: APPLYING THE DIETARY REFERENCE INTAKES 67
SUMMARY
The DRI values can be used by nutrition professionals to assess and plan the
nutrient intakes of individuals and of groups. Table 9 summarizes the chapter
discussions on the appropriate uses of each of the DRI values to achieve these
goals.
Copyright © National Academy of Sciences. All rights reserved.
Dietary Reference Intakes: The Essential Guide to Nutrient Requirements
http://www.nap.edu/catalog/11537.html
68 DRIs: THE ESSENTIAL GUIDE TO NUTRIENT REQUIREMENTS
TABLE 9 Using the DRIs to Assess and Plan the Nutrient Intakes of
Individuals and Groups
EAR RDA AI UL
When Assessing Diets
For individuals: Usual intake Not recommended Usual intake at Usual intake above
below the EAR for use when or above the AI the UL may place an
likely needs to assessing nutrient has a low individual at risk of
be improved. The intakes of probability of adverse effects.
probability of individuals. inadequacy.
adequacy is 50
percent or less.
For groups: Used as part of Not used when Limited Used to estimate the
the EAR cut-point assessing nutrient application. proportion of a group
method to intakes of groups. Groups with mean at potential risk of
determine the or median intakes adverse effects from
prevalence of at or above the excessive nutrient
nutrient AI can generally intake.
inadequacy within be assumed to
a group. have a low
prevalence of
inadequate
intakes.
When Planning Diets
For individuals: Intake at EAR Low probability of Intakes at AI will Low probability of
has 50 percent inadequate intake likely meet or adverse effects from
probability of not at RDA. Therefore, exceed an excessive
meeting often used as a individual\u2019s consumption so
requirement. guide. requirement. average intake
should not exceed
the UL.
For groups: Aim for an Not used when Use as a target Aim for an
acceptably low planning the for the mean or acceptably low
prevalence of nutrient intakes median intake. prevalence of intakes
intakes