Iron metabolism

• Total iron content in body is 3-5 g
• 70% is in RBCs and 5% in myoglobins
• Present as Hemoglobin, myoglobins, transferrin, ferritin, hemosiderin , etc

• Hemoglobin and myoglobin constituent
• Cytochrome contains iron, necessary for cellular respiration
• Peroxidase and Catalase enzymes have iron

BEST –Organ meat

GOOD – leafy vegetables, pulses, cereals, Apple, fish, dry fruits

POOR – Milk, week, polished rice

• Iron found in foods is in the ferric form and is bound to proteins or organic acids.
• But iron in the ferric state is not soluble and difficult to absorb
• Hydrochloric acid in the stomach releases this ferric ion
• Reducing substances such as Vitamin C and cysteine convert ferric Ion to ferrous ion which is taken inside the intestinal cell
• Inside the cell ferrous ion is again converted into ferric form by ferroxidase. Ferric Ion then combines with apoferritin to form ferritin. This is the temporary storage.
• When iron enters the plasma from the intestinal cells it is free from apoferritin and is in the Ferrous form again.
• In the plasma it is again converted into its ferric form buy a copper containing protein called ceruloplasmin.
• Now, this ferric ion in the plasma binds with a protein called as transferrin
• On reaching various tissues iron is free from transferrin and stored again in the form of ferritin.

(Hemosiderin is another storage protein which functions the same)

• Iron is not excreted into urine
• Excretory modes include bile ,sweat , etcwhich is very low ( 1-3 mg/day )
• Thus in order to equilibriate the input with the output, only that much amount is absorbed

Iron deficiency Anemia

• Most common anaemia in the country
• Occurs due to either inadequate intake or impaired absorption of iron or due to heavy blood loss
• It is characterized by microcytic hypochromic anaemia
• It is treated by supplementation of iron along with Folic acid and Vitamin C to aid the absorption process

Hemosiderosis

• It occurs due to presence of excess of iron in the body
• Due to high iron levels the protein hemosiderin is used for storage of iron since iron is not easily excreted.

Hemochromatosis

• It is a condition in which iron is directly deposited in the tissues
• This condition sometimes accompanies hemosiderosis
• It leads to a condition clinically called as bronze diabetes.