RNI 2005-IRON
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Transcript of RNI 2005-IRON
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RECOMMENDEDNUTRIENT INTAKE 2005
FOR IRON
SITI HAJAR BINTI MUSTAFFA
MCL, P 62268
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THE ROLE OF IRON IN HUMAN METABOLIC
PROCESSES
As a carrier of oxygen to the tissues from thelungs by red blood cell haemoglobin
As a transport medium for electrons within cells
As an integrated part of important enzyme
systems in various tissues
Iron deficiency
Impair work performance, IDA, preterm birth, LBW,maternal mortality, impaired cognitive development of infants,
neonatal mortality
Food Sources:
Chicken,spinach,egg,wholemeal bread,lean beef meat,soya bean curd,fresh cockles
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1)FACTOR AFFECTING IRON REQUIREMENT
The iron status of the subjects
The body iron stores regulator play an important part in regulatingiron absorption ( absorption when stores are low & when they are
high)
During - iron balance (when absorption is smaller than losses) ironstore 1st depleted (serum ferritin is lowered) which is successively
associated with continuos in dietary iron absorption
When iron store are depleted there will be a concomitant reduction in
the concentration of Hb.T
his reduction is also associated with anincrease in iron absorption
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Heam Iron( derived from Hb &myoglobin of flesh foods- meat,fish
& poultry
Better absorbed (soluble at thepH at small intestine)
People absorbed 15-35% of heam
iron they consumed (Insel et al2003)
Can be degraded & converted tononheam iron if foods are cookedat high temperature for too long.
Non-heam Iron( plant foods:bread,cereal,dark leafy vegetables
& egg)
Less easily absorbed by the body.
Nonheme iron often containphytates :bind to iron and carry it
through the digestive tractunabsorbed.
The foods with high iron contentarent necessarily the bestsources of iron.
By weight, soybeans haveroughly twice the iron of beef.
But only about 7% of the iron insoybeans is absorbed.
Spinach is also high in iron, butless than 2% of the iron in cookedspinach is absorbed (Scrimshaw1991).
2) FACTOR AFFECTING IRON REQUIREMENT
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Enhancers
Ascorbic acid,(nonhemeiron) Vitamin C 25 mg of
ascorbic acid,1/3 glass of
orange juice (Hallberg,1981)*possibly more if the mealcontains many inhibitors of
iron absorption (FAO 2002 &Fidler et al 2009)
Beef(Hurrell et al 2006),Meat(FAO2002) *associated with a lowerprevalence of irondeficiency.
Citric acid (Hallberg L &Rossander-Hulten 1984)
Inhibitors
Phytic acid (grains &legumes)
Mineral : Calcium(Hellberg1998 & Perales et. al
2006)*avoid consume highlevels of calcium (>40 mg)during meals that areintended to boost ironlevels
Soy protein: In infant foodscontaining soy proteins, theinhibiting effect can beovercome by the addition ofsufficient amounts ofascorbic acid (FAO,2002)
For instance, experimentshave demonstrated thatpeople absorb much lessiron from bread when theirmeals include egg protein,tea, peppermint,chamomile, or coffee (Hurrell etal 1999; Hurrell et al 1988).
3)FACTOR AFFECTING IRON REQUIREMENT
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The absorption and utilization of a nutrient by the body /Kadardan batas penyerapan suatu drug/nutrisi daripada bentuk dosejke dalam ruang dalaman tubuh.(Dewan Bahasa & Pustaka)
Diet contain smaller portions of meat + fish ,high pyhtates +some vegetarian meals each week : iron bioavailability 12%
In vegetarians : bio-availability is usually , the absence of meatand fish and a high intake of phytate and polyphenols
In countries or for certain groups in a population with a veryhigh meat intake, the bio-availability may rather be around 18%
The absorption of heam iron varies from 40% during irondeficiency to about 10% during iron repletion
The absorption of non heam iron differs depending on thepresence of other dietary components & physiological conditions
It is important to adjust absorbed iron req according to differenttypes of diet esp. in vulnerable group
4)FACTOR AFFECTING IRON REQUIREMENT
Bioavailability
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SETTING IRON REQUIREMENTS (ADOPTED FROM FAO 2002)
Basal iron losses
Iron for growth
Menstrual iron lossesPhysiologicalrequirements
10% (diet of the poor orvegetarian)
15% (western diet :depending on meat))
The amountiron in thefood+ its
bioavalability
*Related to bodysurface area
*A non-menstruating55-kg women loses
about 0.8 mg Fe/dayand a 70-kg man loses
about 1 mgThe total amount lost
is estimated at 14g/kg body weight/day
(1mg = 1000 g)
Full-term infant, IR will rise markedlyafter age 4-6 months & amount to about
0.7-0.9 mg/day during the remaining partof the first year.
These requirements are therefore veryhigh : relation to body size and energy
intake
Total Absolute Requirements =Requirement for growth + basal losses +
menstrual losses (females only)
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RECOMMENDED INTAKEFOR IRON : RNI
MALAYSIA,2005
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability
10 15
Infants
0-5months a a
6-12 months 9 6
a: Neonatal iron stores aresufficient to meet the iron
requirement for the 6 mons infull term baby, 4-6 mons
provided through breast milk
body iron need due to in basal ironlosses , growth & in iron store from
birthTotal iron req: 0.93mg/day
consideration basal iron losses,0.17mg/day & iron for growth 0.55mg/day
Iron sources : breast milk &complementary food
Iron Supplements Reduce the Risk of Iron DeficiencyAnemia in Marginally Low Birth Weight Infants (
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Group
Age
Bodyweight
Required Ironintakes for
Growth
Basal Ironlosses
Total AbsoluteRequirements
Mean Median Median 95th
percentile
(Years) (kg) (mg/day) (mg/day) (mg/day) (mg/day)
Children 0.5-1 9 0.55 0.17 0.72 0.93
1-3 13.3 0.27 0.19 0.46 0.58
4-6 19.2 0.23 0.27 0.50 0.63
7-10 28.1 0.32 0.39 0.71 0.89
Iron intakes required for children: median basal iron
losses, and total absolute iron requirements (FAO 2002)
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability
10 15
Children
1 - 3 years 6 4
4 - 6 years 6 4
7 - 9 years 9 6
TIR : 0.58mg/day
TIR: 0.63mg/day
TIR: 0.89mg/day
Mean increase of wt from age 2 till onset of
puberty averaged 2.5-2.75kg/yrBasal iron losses : 0.2-0.4mg/day
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GroupAge
Bodyweight
RequiredIron
intakes
forGrowth
BasalIron
lossesMenstrual losses
Total AbsoluteRequirements
Mean Median Median 95th
percentile
Median 95th
percentile
(Years) (kg) (mg/day) (mg/day) (mg/day) (mg/day) (mg/day) (mg/day)
Males 11-14 45 0.55 0.62 1.17 1.46
15-17 64.4 0.60 0.90 1.50 1.88
18+ 75 1.05 1.05 1.37
Females 11-14 b 46.1 0.55 0.65 1.20 1.40
11-14 46.1 0.55 0.65 0.48 c 1.90 c 1.68 3.27
15-17 56.4 0.35 0.79 0.48 c 1.90 c 1.62 3.10
18+ 62 0.87 0.48 c 1.90 c 1.46 2.94
Iron intakes required for males & female (FAO 2002)
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability
10 15Boys
10-14 yrs 15 10
15-18 yrs 19 12
Girls
10-14 yrs b 14 9
10-14 yrs 33 22
15-18 yrs 31 21
b:non-menstruating
amount compared to boysat the same age (take
consideration on themenstrual losses for every
month)
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability
10 15
Men
19-65 yrs 14 9
>65 yrs 14 9
Women
19-50 yrs
(Pre-menopausal)
29 20
51-65 yrs
(Menopausal)
11 8
>65 yrs 11 8
TIR : 1.37mg/day
TIR : 1.13mg/day
TIR : 2.94mg/day
For men & menopausal women : to estimate TIR based on basaliron losses
Menstruating women, the estimate TIR derived from basal ironlosses (0.87mg/day)& menstrual loss( 1.90mg/day)
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Iron requirements(mg)
IRON REQUIREMENTS DURING PREGNANCY 300
Foetus Placenta 50
Expansion of maternal erythrocyte mass 450
Basal iron losses 240
Total iron requirement 1040
NETIRON BALANCE AFTER DELIVERY
Contraction of maternal erythrocyte mass +450
Maternal blood loss -250
Net iron balance +200
Net iron requirements for pregnancy if sufficient maternal iron stores arepresent (1040 - 200 = 840)
840
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IRON REQUIRED DURING PREGNANCY
To increase the haemoglobin mass of the mother, which occurs inall healthy pregnant women who have sufficiently large iron
stores or who are adequately supplemented with iron.
The increased haemoglobin mass is directly proportional to the
increased need for oxygen transport during pregnancy and is oneof the important physiologic adaptations that occurs in pregnancy
Iron absorption during pregnancy is determined
The amount of iron in the diet
Its bio-availability (meal composition)
The changes in iron absorption that occur during pregnancy
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability10 15
Pregnancy
1st trimester e e
2
nd
trimestere e
3rd trimester e e
1st trimester : iron needs remain atthe level of replacing basal iron losses
since there is no menstrual loss
2nd trimester: iron absorption isincreased by about 50 percent
3rd trimester it may increase by up to
about four times
An adequate iron balance can be achieved if iron stores of 500 mg areavailable (uncommon to have iron stores of this size)
e:It is recommended that iron supplements in tablet form be given to allpregnant mother because of the difficulties in correctly evaluating iron status
in pregnancy with routine laboratory methods.In the non-anemic pregnant woman , daily supplement 100mg of iron given
during 2nd half of pregnancy are adequateIn anemic women higher doses are usually required
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Malaysia (2005)
Age group RNI(mg/day)
% Bioavailability
10 15
Lactation
0-3 months 15 10
4-6 months 15 10
7-12 months 15 10
7-12 months h 32 21
In lactating women, the daily iron loss inmilk is about 0.3 mg. Together with the
basal iron losses of 0.8 mg, the total iron
requirements during the lactation periodamount to 1.1 mg/day.
h: Lactating women with menstruation
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Age group RNI(mg/day)
% Bioavailability
10 15
Infants
0-5months a a
6-12 months 9 6
Children
1 - 3 years 6 4
4 - 6 years 6 4
7 - 9 years 9 6
Boys
10-14 yrs 15 10
15-18 yrs 19 12
Girls
10-14 yrs b 14 9
10-14 yrs 33 22
15-18 yrs 31 21
Men
19-65 yrs 14 9
>65 yrs 14 9
Women
19-50 yrs 29 2051-65 yrs 11 8
Pregnancy
1st trimester e e
2nd trimester e e
3rd trimester e e
Lactation
0-3months 15 10
4-6 months 15 10
7-12 months 15 107-12 months h 32 21
Malaysia 2005
Age group RDI (mg/day)
Infants
< 1 yrs none
Children
1 - 3 years 10
4 - 6 years 10
7 - 9 years 10
Boys
10-12 yrs 10
13-15 yrs 18
16-19 yrs 18
Girls
10-12 yrs 10
13-15 yrs 24
16-19 yrs 28
Men
20-39 yrs 9
40-49 yrs 9
50-59 yrs 9
>60 yrs 9
Women
20-39
yrs 2840-49 yrs 28
50-59 yrs 9
>60 yrs 9
Pregnancy
1st trimester g
2nd trimester g
3rd trimester g
Lactation
1st 6 mons g2nd 6 mons g
Malaysia 1975
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DISCUSSION
In RDI 1975, no recommended iron for infant
Children 1-6 years RNI 2005 recommended lowerthan 10mg/day in RDI 1975
Adolescent , RNI 2005 for both boys & girls for allage groups are higher than the RDI 1975.Thistrend continued in the adult men & women
Pregnancy, both RNI 2005 & RDI 1975 , no ironrecommendation : iron supplement
RDI 1975 no recommendation for lactatingmother, RNI 2005 recommendation depending onbioavailability
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