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


10 mg/day

Menstruating women

18 mg/day

Pregnant women

40 mg/day

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)

Promoting Factors

Inhibiting Factors

Amino acids

Phytates, oxalates

Acidic pH

Alkaline pH

Low Phosphate diet

High phosphate diet

  • 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


  • 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.


  • 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.


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