Iron Hertanto W Subagio
Nov 08, 2014
Iron
Hertanto W Subagio
Iron (Fe)
Functions a key attribute of iron is
its ability to take up and release oxygen atoms and electrons. This allows it to participate in carrying oxygen in the blood and transferring electrons in the electron transport chain of the cell mitochondria
• Carrier of oxygen in the blood (Hb).
• Storage of oxygen in muscle (myoglobin)
• Involved in electron transport chain and production of ATP (cytochromes)
Sources
• Heme iron
- animal ( ± 30%)
• Non Heme iron
- vegetable, legumes etc.
Internal cycle of iron
Absorptioniron status regulated through absorption
Increase- Acid in stomach
- Heme iron
- High body demand
- Low body stores of iron
- Meat protein factors (MPF)
- Vit C (converts ferri to ferro)
Decrease- Phytic acid (dietary fibre)
- Oxalic acid
- Polyphenols (tea, coffee)
- Full body stores of iron
- Excess of other minerals (Zn, Mn,Ca)
- Reduction in stomach acid
- Antacid
Iron Absorption
Model of iron absorption
Iron in the intestinal lumen
Enterocytes in the crypts
Enterocyte along the villus
Intestinal iron absorption
Iron in the human body
Transport
- Transferrin is a protein that transports iron in the blood
- When iron stores are adequate all iron binding sites are saturated
-Transferrin can be used as an indicator of overload or deficiency
- Almost all cells in the body have transferrin receptor (TfR)
- Serum soluble Tfr (sTfR) is a good indicator of deficiency.
Sintesis Hemoglobin
Internalisasi besi
Serum transferrin receptor(sTfR)
Storage Ferritin is the primary store of iron
Iron not taken up by transferrin is stored as ferritin in
the intestinal wall (short term store)
also stored in the liver and spleen as ferritin
Hemosiderin is a stable iron-protein compound in the
liver that stores iron when iron exceeds the storage
capacity of ferritin.
Iron Losses average iron loss of 1 mg / day in men and post menopausal
women
sweat and urine = negligible
exfoliation of the skin and GIT
menstruation
Deficiency and excess
Deficiency
IDA – high prevalence Reduced cognitive
functioning Reduce capacity for
physical work Increased maternal
mortality Stages : normal- depletion of
storage- IDE – IDA.
Excess
Haemochromatosis – genetic disorders
Fe deposits cause cell damage in pancreas, liver and heart
Leads to diabetes, liver and heart failure
Tahap deplesi besi dan indikatornya
Table 1. Changes in Laboratory Test in Relation to progression
Of Iron Deficiency
SID IDE IDA Serum Ferritin D D D Serum TfR N I I Serum Iron N D D Total Iron Binding Capasity N I I Transferrin Saturation N D D Erythrocyte Protoporphyrin N I I Mean Cell Volume N N D Red Cell Distribution Width N N I Hemoglobin N N D Hematocrit N N D Adapted from Cook and Finch and Skikne et al, 1990. SID : Storage Iron Depletion IDA : Iron Deficient Erythropoiesis IDE : Iron Deficiency Anemia
Perubahan parameter pada
defisiensi besi
Diagnosis defisiensi besi berdasar feritin dan sTfR
Public health programs
supplementation
fortification
dietary modification
food processing :
reduce inhibitory factors
education
Fig.1. Elements of successful iron supplementation programs
Policy making
Monitoring and Evaluation
Tablet Supply Adequate budget Data Base Ordering number In target group + 25% surplus Timely ordering Distribution System
Delivery System Accessible to Target group Motivated, Well- Trained Approachable staff
Consumer demand Good Quality Supplements Communications To educate Public and Promote Program
Coverage Do intended
Recipients get Supplements?
Compliance
Do recipients take the supplements
Impact
Reduction of Iron Deficiency anemia
Elements of successful iron supplementation programs
Allen et al. 2000
Suplementasi besi gagal karena tingginya prevalensi kurang gizi
kronik dan defisiensi berbagai zat gizimikro lain
Broek dan Lestky 2000
Among anemic pregnant women only 53% showed biochemical evidence of iron deficiency.
That is the maximum proportion of people among whom anemia could be expected to respond to the administration of iron
Prevalensi defisiensi zat gizimikro pada kasus anemia
01020304050607080
vit A Besi Seng B12
Defisiensi besi belum tentu merupakan penyebab dominan anemia
Berapa % anemia yg bisa disembuhkan dengan suplementasi besi ?
Keterangan : Seng dan Cu tak diperiksa di Malawi dan Nepal
Prevalensi defisiensi zat gizimikro pada ibu hamil anemia di Karangawen, Malawi dan Nepal
Pola defisiensi zat gizimikro pada kasus anemia
3.70%
55.60%
37.00%
3.70%
besi besi+gm lain gm lain tdk defisiensi gm
Defisiensi gizimikro tunggal jarang terjadi
Apakah semua yg defisien besi bisa sembuh dg suplementasi besi ?
Perbandingan defisiensi zat gizimikro pada ibu hamil yg anemia di Karangawen dan Malawi
Causes of microcytic anemia
Langsung pakai obat tambah darah untuk mengatasi anemia ?
Perubahan kadar Hb ibu hamil yang mendapat suplementasi
besi