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).


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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


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)


% 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)


% 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)


% 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)


% 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)


% 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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% 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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Documents

RNI 2005-IRON