Human Nutrition 3(3+0)

Lesson 38 : Iron

Absorption of Iron

Iron occurs in foods in two forms as

• haem iron in meat and other animal tissues. Haem iron is directly absorbed to an extent of 60 – 70%.

• non haem or inorganic iron in other plant foods.

The inorganic iorn in foods after digestion is converted to ferrous form before absorption through the brush border cells in intestines.

After absorption iron enters the blood and some of it is stored as ferritin in the mucosal cells. Vitamin C enhances Fe absorption.

Distribution of iron to different tissues, Iron is converted to its transport form before being distributed to the various tissues. The ferrous iron absorbed into the plasma is oxidized to ferric state by ferroxidase enzyme. The oxidized/ferric form of iron combines with plasma protein transferrin and is then transported to the bone marrow for incorporation in haemoglobin of RBCs. In haemoglobin, ferric iron is again reduced to ferrous form.