Factors Affecting Iron Absorption

The factors increasing and inhibiting Iron absorption are as follows:

   Factor Increasing Iron Absorption

  1. Conditions Associated with a Higher Apoferritin Level in Mucosal cells of the small Intestine: These includes the following:
    After Hemorrhage: This causes and increased rate of blood cell formation which puts excessive demands on the iron stores of the body. The ferritin of the intestinal mucosal cells (as well as that of other body tissues) gives up its iron thus liberating apoferritin.
    Iron Deficiency Anemia: Here again apoferritin content of the intestinal mucosal cell is high.
    On going to high altitudes: This also causes and increased red cell formation which results in a depletion of iron contained in ferritin and thus liberates apoferritin in the intestinal mucosal cells. Repeated Administration of Iron: This stimulates the synthesis of apoferritin in the intestinal mucosal cells and thus iron absorption is increased. Unnecessary iron medication over prolonged periods can thus lead to excessive iron absorption which be harmful.

  2. Taking Ascorbic Acid, Succinic Acid and Sorbitol Along with Iron: Ascorbic acid favors reduction of Fe+++ to Fe++; the latter is more readily absorbed.

  3. Intake of Inorganic Iron: More iron is absorbed if it is ingested in inorganic form.

  4. Pathological Conditions: Hemochromatosis is a pathological condition in which an unknown mechanism causes an increased rate of iron absorption. The excess of iron thus absorbed is deposited in body tissues which interferes with their functions. In this disease body iron content may be up to 50 grams as against a normal content of only 3 to 5 grams. More iron is also absorbed in cirrhosis, portacaval shunts and some forms of pancreatic insufficiency.

  5. Administration of cobalt and erythropoietine and the later stages of pregnancy.

   Factors Inhibiting Iron Absorption

  1. Malabsorption Syndromes: These include steatrorrhea, sprue, and celiac disease.

  2. Diarrheal Diseases: In these conditions there is less time for Iron absorption.

  3. An excess of Phosphates, oxalates or phytic acid: These form complexes with iron which are insoluble and cannot be absorbed. Vegetable food have an excess of phosphates and interfere with iron absorption.

  4. Subtotal gastrectomy: There is interference with the reduction of Fe+++ which normally occurs mainly in the stomach.

  5. Surgical removal of the upper small intestine: This results in a loss of surface concerned with iron absorption because most of the iron is normally absorbed here.

  6. Food intake along with Iron: Less medicinal iron is absorbed if ingested along with food especially eggs because of the formation of insoluble iron complexes.

  7. Antacid therapy: Iron absorption is also decreased by a simultaneous intake of antacids; achlorhydria has also the same effect.

  8. Chronic infections can also be the cause.