Macromineral iron - Introduction, Biochemical role, Recommended dietary Allowance of iron, dietary sources of iron, Deficiency diseases of iron - Hemochromatosis, hemociderosis.
3. Iron - Introduction
• The total content of iron in the adult body is 3-
5 g.
• About 70% of this occurs in the erythrocytes
of blood as a constituent of hemoglobin.
• Atleast 5% of body iron is present in
myoglobin of muscle.
4. Iron - Introduction
• Heme is the most predominant iron-containing substance.
• It is a constituent of several proteins/enzymes
(hemoproteins) - hemoglobin, myoglobin, cytochromes,
Xanthine oxidase, catalase, tryptophan pyrrolase,
peroxidase.
• Certain other proteins contain non-heme iron e.g.
transferrin, ferritin, hemosiderin.
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6. Iron – Biochemical Functions
I. Iron mainly exerts its functions through the
compounds in which it is present.
o Hemoglobin and myoglobin are required
for transport of O2 and CO2.
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10. Iron – Biochemical Functions
II. Cytochromes and certain non-heme proteins
are necessary for electron transport chain
and oxidative phosphorylation.
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12. Iron – Biochemical Functions
III. Peroxidase, the lysosomal enzyme, is
required for phagocytosis and killing of
bacteria by neutrophils.
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15. Iron – Daily Requirements
Adult men - 10 mg/day
Menstruating woman - 18 mg/day
Pregnant and lactating woman - 40 mg/day
19. Iron – Disease states
I. Iron deficiency anemia: This is the most prevalent
nutritional disorder worldover, including the well
developed countries (e.g.USA).
Several factors may contribute to iron deficiency
anemia.
These include inadequate intake or defective
absorption of iron, chronic blood loss, repeated
pregnancies and hookworm infections.
20. Iron – Disease states
• Strict vegetarians are more prone for iron
deficiency anemia.
• This is due to the presence of inhibitors of iron
absorption in the vegetarian foods besides a
relatively low content of iron.
21. Iron – Disease states
• Iron deficiency anemia mostly occurs in growing children,
adolescent girls, pregnant and lactating women.
• It is characterized by microcytic hypochromic anemia with
reduced blood hemoglobin levels (<12 g/dl).
• The other manifestations include apathy ( dull and
inactive) sluggish metabolic activities, retarded growth and
loss of appetite.
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24. Iron – Disease states
II. Hemosiderosis: This is less common disorder and is
due to excessive iron in the body.
• It is commonly observed in subjects receiving repeated
blood transfusions over the years e.g. patients of
hemolytic anemia, hemophilia.
• As already stated, iron is a one-way compound.
• Excessive iron is deposited as ferritin and
hemosiderin.
26. Iron – Disease states
III. Hemochromatosis: This is a rare disorder
in which iron is directly deposited in tissues
(liver, spleen, pancrease).
• Hemochromatosis, sometimes causes a
condition called bronze diabetes.