Download Dietary Reference Intakes

DIETARY REFERENCE INTAKES
(DRIs):
DRIs): 10 Years Later
Korean Nutrition Society
November, 2004
Allison A. Yates
DRIs
Dietary Reference Intakes
Director,
Nutritional Sciences
ENVIRON Health Sciences Institute
Funding for the DRIs has been provided by the U.S. DHHS (Office of Disease Prevention and Health
Promotion, Food and Drug Administration, Centers for Disease Control and Prevention, and NIH);
USDA; U.S. Army; Health Canada; the Dannon Institute;International Life Sciences Institute-North
America, and the DRI Corporate Donors’ Fund (contributors include Roche Vitamins, Kemin Foods;
M&M/Mars; Mead Johnson Nutritionals; and Nabisco Foods Group)
121-03
Food and Nutrition Board
119-02
Recommended Dietary Allowances
1941
Energy
Protein
2
minerals (Ca, Fe)
6 vitamins (A, C, D, thiamin, riboflavin,
niacin)
159-02
Recommended Dietary Allowances
1989
Energy
Protein
7
minerals (Ca, Fe, P, Mg, Zn, I, Se)
vitamins (A, C, D, thiamin, riboflavin,
niacin, E, K, B6, B12, folate)
Safe and adequate daily dietary intakes
(biotin, pantothenate, Cu, Mn, F, Cr, Mo)
11
160-02
402-01
Definition of RDAs
“. . . levels of intake of essential nutrients
considered, in the judgment of the Food
and Nutrition Board on the basis of
available scientific knowledge, to be
adequate to meet the known nutritional
needs of practically all healthy persons.”
NRC, 1974, 1980, 1989
181-01
FNB 1994 Concept Paper
Focused on Need to Include
•
•
•
•
•
•
Recommendations to meet variety of uses
Concepts of reduction of risk to chronic
disease
Review of other food components
Rationale for functional end points used
Open dialog with interested groups
Estimates of upper limits of intakes
126-01
401-01
Dietary Reference Intakes
Process for Setting DRIs
Standing Committee on the Scientific
Evaluation of Dietary Reference Intakes
Committee
of experts
Literature review
Solicitation of advice
Panels
Ca, Vitamin D, Phosphorus, Mg, F
—Workshops
—Scientific
Meetings
—Correspondence
NRC
Folate, B12, B Vitamins, Choline
Upper Reference
Levels
Subcommittee
Vitamins C and E, Se, ß-carotene
and Other Carotenoids
Vitamins A and K, As, B, Cr, Cu,
Fe, I2, Mn, Mo, Ni, Si, V, Zn
Risk Assessment
Model
Energy, CHO, Lipids, Amino Acids,
Protein, Fiber, Physical Activity
Uses of DRIs
Subcommittee
Assessment
Planning
Electrolytes, Water
review
Other Food
Components?
147-01
Alcohol?
149-05
Top 10 DRI Questions
What’s
wrong with the old RDAs? Can’t
you just update the numbers?
Is DRI the new term for RDA?
What’s the difference between an RDA
and an AI?
142-02
Top 10 DRI Questions
Top 10 DRI Questions
Should
Why
are some of the ULs less than the
new RDAs for the same nutrients?
Why were DFEs developed?
Why were REs changed to RAEs?
How can the UL for sodium be so low?
No one eats such a small amount (2,300
mg)
I be concerned that the current
food label in the U.S. uses 15 mg of zinc
as the DV, and this is more than the new
RDA for adults (11 mg), and twice the UL
for children 1-3 years (7)?
Which DRI should I use to plan diets with?
Why aren’t there different ULs for men and
women?
142-02
Why DRIs?
DRIs?
Conceptual Approach
Criteria for Establishing RDAs
Scientific Database
Quantitative
dietary recommendations
need to address multiple users and
meet multiple needs
Observed
intakes in healthy populations
observations
Balance studies
Depletion/repletion studies
Animal experiments
Biochemical measurements
Epidemiological
—Labeling
—Limits
for fortification
adequacy of diets of population
groups
—Assessing
One
number can’t do it all
142-02
130-01
Dietary Reference Intakes (DRIs)
DRI is a collective term that includes nutrientbased dietary reference values:
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
Acceptable Macronutrient Distribution Range
(AMDR)
199-01
Dietary Reference Intakes (DRIs)
DRI is a collective term that includes
nutrient-based dietary reference values:
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
199-01
Dietary Reference Intakes
Dietary Reference Intakes
EAR
UL
RDA
AI
0.5
0.5
Risk of excess
Risk of inadequacy
Frequency Distribution
of Individual Requirements
2 s.d.
Observed level of intake
EAR
2 s.d.
Increasing Intake
Increase
196-02
194-01
Probability That Specified Usual Iron Intake Would
Be Inadequate to Meet the Needs of a Randomly
Selected Menstruating Woman1
Model for Dietary Reference Values
Frequency Distribution of
Individual Requirements
1
0.9
Probability of
Inadequacy
0.8
Maintain Stores
0.7
0.6
0.5
Maintain Biochemical Function
0.4
0.3
0.2
0.1
Increasing Intake
3 ab
6 ay
9 10
EAR - Based on Indicator
of Adequacy
RDA
Hb > 11.0 g/dl
0
6
195-02
G. Beaton, 1994
It Depends on the Criterion Chosen
0.5
0.5
RDA1
RDA2
Increasing Intake
217-03
10
12
14
16
Usual level of iron intake
(mg/day)
18
20
216-03
Why an EAR?
To
UL
Risk of excess
Risk of inadequacy
EAR1 EAR2
8
establish the recommendation
for an individual
To assess adequacy of population
intakes
Dietary Reference Intakes (DRIs)
Relationship of EAR and RDA
Estimated
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
Recommended
Dietary Allowance (RDA)
= requirement for 97.5% of the
population, so plan diets for individuals
using this DRI
RDA = EAR + 2 SD
(if symmetrically distributed)
199-01
205-02
Dietary Reference Intakes (DRIs)
Model for Dietary Reference Values
Frequency Distribution of
Individual Requirements
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
Increasing Intake
3 ab
6 ay
9 10
EAR - Based on Indicator
of Adequacy
RDA
195-02
199-01
AI
Adequate Intake
Dietary Reference Intakes
Based
EAR
UL
RDA
AI
0.5
0.5
Risk of excess
on observed or experimentally
determined approximations of the
nutrient intake by a defined population or
subgroup that appear to sustain a
defined nutritional state
Used as a guide to nutrient intake for the
individual
Risk of inadequacy
Average Requirement (EAR) =
requirement for 50% of the population
Observed level of intake
207-01
Increase
196-02
UL
Tolerable Upper Intake Level
Dietary Reference Intakes (DRIs)
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
The highest level of daily nutrient
intake that is likely to pose no risks of
adverse health effects to almost all
individuals in the general population
•
•
Not a recommended level of intake
Not a level that is desirable to attain
199-01
211-02
Unique Characteristics of
Nutrients vs. Food Contaminants
Why a UL?
Absence
To
identify when it’
it’s possible to have
adverse effects or toxicity when
consuming too much of a nutrient
of dose-response data
available human or animal chronic
studies
Few surveillance studies to establish NOAEL
(No Observed Adverse Effect Level)
Available databases often concentrate on
supplement intake, not total intake
Significant differences in bioavailability
227-01
Few
Effect of Uncertainty Assessment on UL
Risk Assessment for Nutrients
Risk of Adverse
Effects
Hazard
Identification
Dose-Response Assessment
Exposure Assessment
Risk Characterization (UF)
Risk of Adverse
Effects
Risk Management (FDA)
231-01
RDA
UL
NOAEL
LOAEL
100%
50%
100%
RDA
NOAEL
UL
LOAEL
50%
Increasing Intake
230-03
Population Prevalence of
Inadequate Intakes
Why an EAR?
To
EAR
Frequency
establish the recommendation for
an individual
To assess adequacy of population
intakes
Intakes
Area estimates
prevalence of
inadequacy
Usual Intake (amount/day)
246-03
Vitamin C Intake for Men and Women
Who Don’
Don’t Smoke (Food and Supplements)
Vitamin C Intake for Men and Women
Who Do Smoke (Food and Supplements)
EAR = 60 mg for Women
75 mg for Men
women below EAR = 10%
men below EAR = 21%
Adjusted EAR = 95 mg for Women
110 mg for Men
women below EAR = 30%
men below EAR
= 52%
479-01
480-01
New Units of Expression
Folate
Vitamin
Folate
“Folate”
Dietary Folate Equivalents
E α - Tocopherol
is generic term that includes
food folates (pteroylpolyglutamates)
and synthetic folic acid
(pteroylmonoglutamic acid).
Food
Vitamin
A Retinol Activity Equivalents
folates must be hydrolyzed in
the intestine prior to absorption, and
are therefore less bioavailable than
synthetic folic acid.
Folate in Foods, Supplements
Dietary Folate Equivalents:
Serving Size
Food Folate:
50%
1 µg DFE = 1.0 µg naturally present folate
(DFE = 1 x weight)
Folate from Fortified Food:
1 µg DFE = 0.6 µg added to foods
85%
(DFE = 1.7 x weight)
Folate from Supplements w/ water:
>90%
1 µg DFE = 0.5 µg from supplements
(DFE = 2 x weight)
DFE
µg
100
100
400
100
667
167
60
20
400
100
33
800
364-02
B12 RDA for Adults Ages 51+ Years
10-30%
Orange juice
120 g
Ready-to-eat cereals
Highly fortified
30 g
Mod. Fortified
1/2 cup
Noodles, rice, pasta
(cooked)
1 cup
Bread
25 g
Supplement
1 pill
Folate
µg
Vitamin A
adults >50 years:
atrophic gastritis ⇒ ↓ absorption of dietary B12
∴ Bioavailability of food-bound B12 for elderly
may be very low for some
EAR,
RDA: no change with age but foods
fortified with B12 (such as fortified cereals) or
B12-containing supplements should meet
most of the RDA of 2.4 µg of B12
Comparison of 1989 and 2001
Interconversion of Vitamin A and
Carotenoid Units
NRC, 1989
IOM, 2001
1 retinol equivalent (RE)
1 retinol activity equivalent (RAE)
= 1 µg all-trans-retinol
= 1 µg all-trans-retinol
= 2 µg all-trans-β-carotene = 2 µg all-trans- β-carotene in
in oil
oil
= 6 µg all-trans-β= 12 µg all-trans-β- carotene
carotene
= 12 µg other dietary
= 24 µg other dietary
provit. A carotenoids
provitamin A carotenoids
1 µg all-trans-retinol = 3.33 IU vitamin A activity from retinol (WHO, 1966)
Required for normal vision, reproduction,
gene expression, embryonic development,
growth, and immune function
Provitamin A carotenoids:
β-carotene
β-cryptoxanthin
α-carotene
Derivation of Retinol Equivalents
NRC, 1989
Old RE for dietary β-carotene: supplemental βcarotene in oil well absorbed, converts to 1/2
vitamin A by weight; other food β-carotene
only 1/3 absorbed, so conversion of food
β-carotene is 1/3 x 1/2 = 1/6
Vitamin A activity of β-cryptoxanthin and αcarotene is 1/2 relative to β-carotene ∴ 1/12
Derivation of
New Retinol Activity Equivalents
IOM, 2001
RAE for dietary β-carotene: 1/6 (not 1/3) relative
to absorption of supplemental β-carotene (in
oil) × conversion of absorbed β-carotene to
vitamin A (1/2) = 1/12
Vitamin A activity of β-cryptoxanthin and αcarotene still 1/2 relative to β-carotene ∴ 1/24
Adverse Effects Considered in
Setting the Upper Level for
Vitamin A
Bone
mineral density
Liver
toxicity
Teratogenicity
Indicators Considered for Estimating the
Average Requirement for Vitamin A
Dark
adaptation
Serum/plasma
retinol concentration
Isotope dilution
Relative dose-response/modified
relative dose-response
Conjunctival impression cytology
Immune function
Adequate liver stores
Upper Levels for Vitamin A
Women of reproductive age
NOAEL (teratogenicity) = 4,500 μg/day = 3,000 μg/day*
UF
1.5
(women of reproductive
All other adults
age)
Bulging
LOAEL (liver toxicity) = 14,000 μg/day = 3,000 μg/day*
UF
5
fontanel (infants)
* From pre-formed vitamin A sources only
Tolerable Upper Intake Levels for
Vitamin A (µg/day)
Life Stage
UL
0–6 mo
7–12 mo
1–3 y
4–8 y
9–13 y
14–18 y
≥ 19 y
600
600
600
900
1,700
2,800
3,000
Preg, Lact
See age group
Vitamin K
Required as a coenzyme for the
synthesis of proteins active in blood
coagulation
and bone metabolism
Special Considerations
Vitamin K – Coumadin interaction
Patients
undergoing anticoagulant therapy are
advised to keep their daily vitamin K intake constant
Adverse Effects Considered in Setting
the Upper Level for Vitamin K
No adverse effects of vitamin K from food
were identified so no UL was set
Vitamin K – vitamin E interaction
Probably
of little consequence in healthy individuals;
patients undergoing anticoagulant therapy should
avoid large intakes of vitamin E
(> 400 IU/day)
Iron
Component of a number of proteins
including enzymes and hemoglobin
Setting the EAR for Iron for
Infants and Children (1–
(1–8 years)
Factorial modeling
Obligatory fecal, urinary, and
dermal (basal) losses
Increase in hemoglobin mass
Increase in tissue (nonstorage) iron
Increase in storage iron
Indicators Considered for Estimating the
Average Requirement for Iron
Serum
ferritin concentration
total iron binding capacity
Serum transferrin saturation
Erythrocyte protoporphyrin
Soluble serum transferrin receptor
Hemoglobin concentration and hematocrit
Erythrocyte indexes
Balance studies
Factorial modeling
Plasma
Setting the EAR for Iron for Children
and Adolescents (9–
(9–18 years)
Factorial modeling
Basal losses
Increase in hemoglobin mass
Increase in tissue (nonstorage) iron
Menstrual iron losses for girls (14–18 years)
Setting the EAR for Iron for
Adults
Factorial modeling
Basal losses
Menstrual losses (premenopausal
women)
Setting the EAR for Iron for
Pregnancy
Basal
losses
Fetal and placental iron deposition
Increase in hemoglobin mass
Adverse Effects Considered for Setting
the Upper Level for Iron*
Zinc
Gastrointestinal distress
Impaired zinc absorption
Cardiovascular disease
Cancer
Major roles:
Catalytic
Structural
Regulatory
UL = LOAEL (gastrointestinal = 70 mg/day ≈ 45 mg/day*
UF
distress)
1.5
*May not protect individuals with hemochromatosis
Adverse Effects Considered in Setting
the Upper Level for Zinc
Immunological response
Serum lipoprotein and
cholesterol concentration
Reduced copper status
Reduced iron absorption
Leukocyte copper concentration
UL = LOAEL (reduced copper = 60 mg/day = 40 mg/day
UF
status)
1.5
Conceptual Framework: Uses of
Dietary Reference Intakes
NUTRIENT
REQT’S
NUTRIENT
INTAKES
PLANNING
DIETS
Group
Indiv.
ASSESSING
DIETS
Group
Indiv.
From: Beaton, 1994
What are the Goals of
Dietary Planning?
Goals are for Intakes
Traditionally, planning
has been for foods
“offered” or “served”
The actual goal,
however, relates to
intakes
This is challenging, as
planners can’t control
intakes
“Optimize prevalence of diets that are
nutritionally adequate without being excessive”
Meet nutrient requirements/recommendations
— for
— for
individuals, low risk
groups, low prevalence
Avoid potential risks of excessive intakes
— for
— for
individuals, low risk
groups, low prevalence
Planning for Individuals
Planning for Individuals
Are there special considerations?
No
Plan to meet RDA/AI
Remain below UL
Meet EER
Stay within AMDR
Pyramid not yet
assessed to determine
whether it requires
revision to DRI
recommended intakes
Still the most useful way
to begin planning
individual diets
Yes
(e.g., smoker - Vitamin C)
other nutrients
Plan appropriate
intakes based on
special considerations
Assessment and Planning
are Linked
Planning for
Homogeneous Groups
Assess
Plan
Energy:
Monitor body weight over
time
Nutrients:
To be confident intakes
meet RDA/AI, need many
days of records
Revise plan as necessary
Select goals for each nutrient of interest
Estimate target usual intake distribution
Plan menus to achieve target usual
intake distributions
Assess results
Step 2: Estimate Target Usual
Intake Distribution
Step 1: Selecting Goals
Acceptable prevalence of adequacy/inadequacy
— No
conventions; judgement is involved
adequate (“almost everyone”), or 2-3%
inadequate
— 97-98%
For nutrients with EAR build directly on
approach used in assessment
When certain assumptions are met:
The proportion of a group with usual
intakes < EAR approximates the
proportion with Intakes <
Requirements
Acceptable prevalence of potential risk of excess
Step 3: Planning Menus
Percent of Individuals
Baseline Usual Intake Distribution
EAR
UL
RDA
For nutrients with EAR:
select initial goal based on target usual
intake distribution
— Median
of the distribution is a useful tool
intakes are usually less than amounts
offered; planning goal may need to be slightly
higher than the median
— But
Usual intake of nutrient (amount /day)
For nutrients with an AI:
AI can serve as a goal for intakes
247-02
Step 4: Assess Results
Percent of Individuals
Target Usual Intake Distribution
EAR RDA
UL
Usual intake of nutrient (amount /day)
247-02
Amounts “offered” may not equal amounts
consumed
Baseline intake distribution may have been
obtained from another group
Shape of intake distribution may change
DRIs Macronutrients:
New Concepts
Adverse Effects Reviewed for
Carbohydrate
Behavior
Dental Caries
Blood Lipid Concentrations
Coronary Heart Disease
Diabetes
Obesity
Cancer
No UL set for Carbohydrate
Minimum amount of CHO = 130 g/d
Limitation on added sugars = < 25% of kcal
Quantitative recommendations for fiber in the diet
Ranges for energy sources
— Acceptable
Macronutrient Distribution Ranges (AMDR)
Physical activity levels to decrease risk of chronic
disease & maintain weight
Recommendations for indispensable amino acids
Protein scoring pattern
Added Sugars
Glycemic Index
Insufficient
evidence in healthy
people for setting a UL for
carbohydrate -containing foods
based on Glycemic Index
Definition of Fiber in the Diet
Dietary Fiber consists of nondigestible
carbohydrates and lignin that are intrinsic and
intact in plants
Functional Fiber consists of isolated,
nondigestible carbohydrates that have beneficial
physiological effects in humans
Total Fiber is the sum of Dietary Fiber and
Functional Fiber
Maximal intake of no more than 25 percent of
energy from Added Sugars is suggested based
on ensuring sufficient intakes of other
micronutrients found in low amounts in food
and beverages that are major sources of added
sugars in the U.S. diet
Food Composition Tables
Dietary Fiber ≈ Total Fiber
Based on few novel fibers in foods
at the present time
Physical Activity Levels (PAL)
Criteria and AIs*
AIs* for Total Fiber (g/day)
AI
Life Stage Criterion
0-6 m
7-12 m
1-3 y
Prevent CHD
4-8 y
Prevent CHD
9-13 y
Prevent CHD
14-18 y
Prevent CHD
19 - 50 y
Prevent CHD
> 50 y
Prevent CHD
Pregnancy
Prevent CHD
Lactation
Prevent CHD
Male
ND
ND
19
25
31
38
38
30
Female
ND
ND
19
25
26
26
26
21
28
29
Physical Activity Level (PAL) =
total energy expenditure ÷ basal energy
expenditure
PA = 1.0 if PAL ≥ 1.0 < 1.4 (sedentary)
PA = 1.12 if PAL ≥ 1.4 < 1.6 (low active)
PA = 1.27 if PAL ≥ 1.6 < 1.9 (active)
PA = 1.45 if PAL ≥ 1.9 < 2.5 (very active)
*AI =14 g/1000 kcal x median energy intake for age group
200-01
(kcal/d)
200-01
Physical Activity
Recommended physical activity level (PAL)
= > 1.6 -1.9
Why?
—
—
—
To decrease risk of chronic disease (CVD)
To maintain ideal body weight (BMI = 18.5 to
25)
For lower weight people to meet micronutrient
& fiber intake recommendations
What is a PAL > 1.6?
—
—
—
How Activities Compare
Metabolic equivalents (METS)
— Walking ~4 mph
4.5
— Golf (with cart)
2.5
— Cycling (leisurely)
3.5
— Golf (without cart)
4.4
— Aerobics
6.0
— Jogging (10-min miles)
10.2
— Swimming
7.0
— Gardening
4.4
— Household tasks, moderate effort 3.5
— Climbing hills
6.9
Maintaining PAL of > 1.6
total activity equivalent to walking at 4
mph for 60 minutes
gardening for 60 minutes
climbing hill for 30 minutes
All activities contribute to increasing
the PAL
Protein Recommendations
RDA = 0.8 g/kg body weight/day using
meta-analysis of nitrogen balance studies
— Same
for men and women based on body
weight
— No differentiation for animal versus vegetable
protein, assumes complementary protein
consumption
— No differentiation for age based on body
weight (thus declining LBM)
200-01
Protein Digestibility Corrected Amino
Acid Scoring Pattern1
Amino Acid
mg/g protein
Histidine
Isoleucine
Leucine
Lysine
Methionine + cysteine
Phenylalanine + tyrosine
Threonine
Tryptophan
Valine
1Based
Dietary Fat
18
25
55
51
25
47
27
7
32
Total Fat
Saturated Fat
Monounsaturated fatty acids
n-6 Polyunsaturated fatty acids
n-3 Polyunsaturated fatty acids
Trans fatty acids
Cholesterol
on reqts for 1-3 y for indispensable amino acids
200-01
Dietary Reference Intakes
No ULs Set for
EAR
UL
RDA
0.5
0.5
WHY?
Risk of excess
Total Fat
Saturated Fat
Monounsaturated Fat
n-6 Polyunsaturated Fats
n-3 Polyunsaturated Fats
Trans Fat
Cholesterol
Risk of inadequacy
Observed level of intake
Increase
200-01
Increasing Intake of Cholesterol on Serum Total Cholesterol
3
Defined Diets (Data from Table 1)
Self-Selected Diets (Data from Table 2)
2.5
Change in Serum TC (mmol/L)
Trans Fatty Acid and Saturated Fat
Intake and LDL:HDL Cholesterol Ratio
196-03
Linear (Defined Diets (Data from Table 1))
Linear (Self-Selected Diets (Data from Table 2))
2
1.5
y = 0.0008x + 0.1737
R2 = 0.1844
1
y = 0.0004x + 0.0108
R2 = 0.1942
0.5
0
-0.5
-1
0
200
400
600
800
Change in Dietary Cholesterol (mg/d)
1000
1200
Dietary Reference Intakes (DRIs)
Primary Fat Recommendations
DRI is a collective term that includes nutrientbased dietary reference values:
Minimize consumption of
Saturated Fatty Acid
Trans Fatty Acid
Cholesterol
while consuming a nutritionally adequate diet
200-01
AMDR
Acceptable Macronutrient
Distribution Range
Recommended range of macronutrient
intakes in a healthy diet
Associated with reduced risk of chronic
disease while providing adequate
intakes of essential nutrients
Given as a percent of energy intake
Example of Amount by Weight of
Macronutrients in a 2,000 kcal Diet
Nutrient
AMDR
Selected Amount Amount for
2,000 kcal
Fat
20–35%
30%
67 g
Linoleic acid*
5–10%
7%
16 g
α-Linolenic acid* 0.6–1.2%
0.8%
1.8 g
Protein*
10–35%
15%
75 g
Carbohydrate*
45–65%
55%
275 g
*More than the AI or RDA for most individuals
Estimated Average Requirement (EAR)
Recommended Dietary Allowance (RDA)
Adequate Intake (AI)
Tolerable Upper Intake Level (UL)
Acceptable Macronutrient Distribution Range
(AMDR)
199-01
Macronutrients with an AMDR
For adults:
Protein
Fat
Carbohydrate
10 - 35%
20 - 35%
45 - 65%
n-6 polyunsaturated fatty acids 5 - 10%
n-3 α-linolenic acid 0.6 – 1.2%
To Obtain Publications and Tables
National Academies Press
1-800-624-6242
http://www.nap.edu
download pdf files
at FNB website:
www.iom.edu/fnb
JADA November 2002 vol. 102, pp. 1621-1630
JADA March 2001 vol.101, pp. 294-301
JADA June 2000 vol.98, pp. 699-706