• Iron is needed in the body to prevent iron-deficiency anaemia,
• for the immune system,
• for carrying oxygen throughout the body as Haemoglobin
• and for helping with energy production as Cytochromes
• RDA for women under 50 years of age is 18 mgr. and 10 mgr. after age 51

• Iron deficiency affects 50% women under age 45.
• Rare in men
• It can be caused by
• menstrual loss, poor absorption,
• and/or a poor diet.
• Its symptoms are
• fatigue,
• cold hands and feet
• loss of appetite,
• increased irritability,
• poor quality fingernails, headaches, and paleness.

• is the most abundant iron compound in the body
• It is the carrier of oxygen in the blood.
• The body contains 0.750 Kg of haemoglobin and this is replaced every 3 months
• Normal turnover requires 6-8 grams of new haemoglobin daily

• Cytochromes
• Are present in the mitochondria and in the endoplasmic reticulum.
• They participate in ATP synthesis as part of the Electron transport system
• Half of them are replaced 132 hours.
• Catalase and peroxidase remove hydrogen peroxide.
• Protect the body against oxidation by peroxide.
• Half of these are replaced every 20 hours.

• A most men contain about 3.7 grams of iron each.
• Most of this, (70%) is present in haemoglobin.
• Some (28%) is stored as ferritin.
• The remainder is in
• myoglobin,
• the cytochromes,
• other haemoproteins, etc.
• There is no mechanism for excreting excesses iron that accumulates in the body.

• Binds non-specifically to many proteins and destroys their structures.
• Acts catalytically in oxidation of unsaturated lipids in cellular membranes.

• Because of this it is always found in bound form.
• There is very little free iron in blood plasma
• This stops bacteria growing in blood.
• Because it is bound iron is NOT get excreted.

• Only by:
• bleeding
• sloughing off of cells (lining of gut)
• menstrual flow
• transfer to a developing fetus.

• Regulation of The body's iron content is only by controlling absorption.

• Eat lean meat, skinless poultry, and fish
• high in absorbable iron.
• Meat fish and poultry effect
• increases uptake from other sources
• Vitamin C-rich fruits and vegetables
• It can almost double absorption.

• Eat lactose-containing food.

• Avoid tea and coffee 1 hr. before or 2 hr after meals
• Tannin decreases iron absorption up to one-third.

Iron metabolism disorders:

• Iron deficiency and iron overload diseases:
• Afflict more than a billion people worldwide.
• Iron overload,
• Haemochromatosis is the most common human genetic disorder
• Affecting up to 1 in 200 Caucasian Americans,
• Causes diabetes, impotence, arrhythmia and liver failure

• Is done in the intestinal mucosal cells
• These cells make an iron-binding protein, apoferritin.
• When blood iron is low:
• little apoferritin is made
• This allows iron to passes through the cells freely into the plasma.
• When blood iron is high
• more apoferritin is made.
• This apoferritin traps iron the cells as ferritin;
• Bound iron is lost into the intestine with dead cells and no absorption occurs

Oxidation changes during digestion and absorption.

• In the stomach.
• Iron III (Fe⁺⁺⁺) is reduced to iron II (Fe⁺⁺).
• the low pH & Reducing agents,
• such as ascorbic acid & lactose
• iron (II) freed from complexes
• In the duodenum.
• An alkaline environment
• Haem is absorbed directly by the mucosal cells.
• Free iron (II) ions are oxidised to iron (III)
• taken up by the mucosal cells.

• There are two major forms of dietary iron.
• Haem iron,
• found primarily in red meats, is the most easily absorbed form.
• Other forms of iron are tightly bound .
• Cooking increase iron availability.
• In some iron-rich foods it is non-absorbable.
• eg spinach. Has oxalate, -->> non-absorbable.
• Phytates, present in unleavened bread

• Iron that is stored in intestinal mucosal cells or in the liver may be transferred into the blood for transport to other tissues.
• The iron (III) storage form must be reduced to iron (II) in order to cross the plasma membrane.
• In the blood, iron (II) is reoxidised to iron (III) by ferroxidase II.

• Iron (III) is carried by the serum protein, transferrin.
• Normally.
• transferrin is only about 1/3 saturated
• An increased of iron can be handled easily.
• The iron binding capacity of serum is almost entirely provided by transferrin.

• Ferritin is main storage compound
• Mostly in the liver,

• Hemosiderin
• If ferritin is saturated, iron forms hemosiderin
• hemosiderin is deposited in the liver and heart.
• Their function can be damaged
• can causes death.

• Idiopathic hemochromatosis
• excess iron is absorption.

• Multiple transfusions
• beta-thalassemia, needs haem supplied by blood transfusion

• Involves artificial removal of iron from the body.
• Bleeding is the treatment of choice for idiopathic hemochromatosis.
• Blood donation
• Bleeding is No good for beta-thalassemia
• chelators are administered which bind iron.
• Chelated iron is excreted in the urine.

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