Author: Ms Christa Maria Joel Moderator- Dr. John Paul Department of Internal Medicine Father Muller Medical College 3rd Year MBBS (2016-2017)

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2. Introduction
■ Iron is an important
element present in
hemoglobin
■ Also an important
component in various
enzymes like
cytochrome p450 which
helps in drug
metabolism etc.
■ Must be maintained in
soluble form to prevent
toxicity. 2

3. Iron intake
■ Daily requirement of iron
in males is 10-20 mg,.
■ For women- 30-40 mg
■ Infants require 1 mg/kg
body weight.
■ Dietary iron is in two
forms
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Heme
iron
Non
heme
iron

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5. Absorption of Heme iron
■ Iron bound to proteins is released by acid & proteases in
the stomach.
■ Ferrous iron oxidized to ferric iron.
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6. Structure and function of heme
■ Gives myoglobin and
hemoglobin the ability to
bind oxygen because of
presence of iron atom.
■ Contributes to red
colour found in muscles
and blood.
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7. Absorption of heme
Heme enters the
enterocytes with
the aid of heme
receptors.
Heme is degraded
to free iron,
bilirubin and
carbon monoxide
by action of heme
oxygenase
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8. Absorption of non heme iron
■ Released from food by action of acid either in ferrous or
ferric state.
■ In the alkaline pH of the duodenum ferric salts are
insoluble whereas ferrous iron is soluble. Therefore most
of the absorbed iron is in the ferrous form.
■ Absorption of iron is influenced by the availability of iron
stores and needs of the body.
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9. Factors affecting iron absorption
Factors which increase iron
absorption
■ Haem iron
■ Ferrous iron
■ Acids like ascorbic acid,
citric acid, hydrochloric acid,
gastric secretions.
■ Solubilising agents like
sugars and amino acids.
■ Iron deficiency
■ Increased erythropoiesis.
■ Pregnancy
■ Hereditary
hemochromatosis
Factors which decrease iron
absorption
■ Inorganic iron and Ferric
iron
■ Alkalis like antacids and
pancreatic secretions.
■ Precipitating agents-
phytates like bran, oats, rye,
fibre & phosphates
■ Iron excess
■ Decreased erythropoiesis
■ Infection
■ Dietary calcium 9

10. Utilisation and excretion of iron
■ Most of the iron is utilized for heme synthesis in
erythroblasts.
■ Iron is also taken up by macrophages by the process of
erythrophagocytosis.
■ Excretion of iron occurs through shedding of enterocytes,
exfoliation of skin, sweat and urine.
■ Loss of blood from the body contributes to the major
source of iron loss.
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12. Specific proteins involved in iron
metabolism and their functions
Duodenal
cytochrome b
helps in reduction
from Fe3+ to Fe2+
Divalent metal
transporter 1
helps in transport
to cell
Ferritin binds to
iron and gets
stored in the cell
Hephaestin helps
in oxidation from
Fe2+ to Fe3+
Ferroportin helps
in transport of
iron into
circulation
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13. Hepcidin
■ A 25 AA peptide which was identified in the year 2000
with antimicrobial activity. Since it is produced by liver it
was named hepcidin (hepatic bactericidal protein).
■ It is an iron regulator that appears to communicate the
status of the body’s iron stores and the demand for
erythropoiesis to the enterocytes and thereby regulate
iron absorption.
■ Hepcidin deficiency- results in hereditary
hemochromatosis as patient absorbs excessive iron.
■ Hepicidin excess- results in anemia of chronic disease.
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14. Iron deficiency
■ One of the most widespread nutritional disorders present all over
the world.
■ Bioavailability of iron in the average Indian diet is low. Milk is a
poor source of iron and hence babies fed on unfortified milk
develop iron deficiency within 6-12 months.
■ Clinical symptoms do not appear till the stores are completely
depleted.
■ Stages of iron deficiency- earliest stage is depletion of iron stores
during which condition is asymptomatic and second stage is tissue
iron deficiency. The third stage is iron deficiency anemia.
■ Prevention- prophylactic supplementation in vulnerable group of
people and fortification of food with iron at community level.
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16. Hemosiderosis
■ It denotes excessive accumulation of iron which is seen
in perons who have excessive inputs of iron over
prolonged periods.
■ Iron is deposited in liver and it undergoes fibrosis.
■ Iron overload can occur in persons having thalassemia,
sickle cell anemia or aplastic anemia who are repeatedly
transfused with blood usually more than 100
transfusions.
■ Iron absorption is very high in cases of hemochromatosis
and thalassemia.
■ Elimination of iron can be enhanced by chelating agents
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19. Hereditary disorders of iron overload
■ Hereditary hemochromatosis- autosomal recessive
condition. HFE gene is mutated. In a middle aged man a
triad of clinical features are seen-
Diffuse Hyperpigmentation
Hereditary
hemochrom
atosis Diabetes mellitus
Hepatic
cirrhosis 19

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21. Hereditary disorders
■ Atransferrinemia
■ Acaeruloplasminemia
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Autosomal recessive
conditions

22. THANK YOU
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