2. ROLE OF IRON IN HEALTH AND DISEASE

3. Learning Objectives Distribution Daily Requirements Dietary sources
Important functions
Absorption & Metabolism
Deficiency diseases

4. FUNCTIONS Shuttles O2 from lungs to all other tissues and
CO2 back from tissues to lungs.
Ability of Hb molecule to take up O2 and release CO2, is dependent on presence of Fe in Hb.
Without Fe, the Hb. molecule cannot perform this function.
The cytochrome enzyme system functions in energy production.

5. Absorption and Metabolism

6. Absorption Heme iron is better absorbed than non heme iron
During states of iron balance, about 10% of dietary iron is absorbed
Figure can increase by 2 or 3 times, during periods of iron deficiency

7. METABOLISM
When iron is needed by the body, Ferritin gives up its iron to the blood stream.
Fe+++ iron is reduced within the mucosal cell to Fe++ form and released.
The apoferritin in the mucosal cell can then combine with dietary iron absorbed in the intestine.
If all the mucosal cells are saturated, no further absorption.

9. Iron Absorption

11. METABOLISM
Most of iron in blood stream is utilized by bone marrow to synthesize Hb.
Some is used by other tissue in the formation of enzyme

12. Factors affecting Iron Absorption
Absorbed through intestinal mucosa, only when needed
Ferrous (Fe++) is better absorbed than Fe+++ (Ferric)
Better absorbed in Acidic medium, by virtue of conversion of ferric to ferrous state.

13. Absorption Absorption increase with need:
Period of rapid growth in infancy.
Childhood and adolescence
During pregnancy,
As a result of blood loss and
At high attitude.

14. Factors
Absorption is more efficient in presence of Vit C, and other reducing substances
Vitamin C and fructose forms soluble complexes with iron and therefore better absorbed.

15. Factors which reduce the iron absorption
High fiber in diet
Tea , inhibit the absorption of non heme iron
Phosphate, Oxalates, Phytates forms insoluble complexes with iron.

16. IRON DEFICIENCY Hypo chromic anemia:
No of RBCs are either normal or reduced
Amount of circulating Hb is reduced
In each RBC the Hb. content fall
Hb low, oxygen carrying capacity is reduced

17. IRON REQUIREMENTS
Due to efficient conservation and reutilization in the body daily physiologic requirement is small.
Healthy man loses about mg/day iron, while women lose about mg/day
10% of average available dietary iron is absorbed which comes to 5-10 mg/day required for men and mg/day required for women

18. IRON REQUIREMENTS Pregnancy increases iron daily need by 3.5 mg/day
To be taken as iron supplement and not diet – 60 mg/day
Lactation iron losses are 0.5 – 1.0 mg/day
Continuous Supplementation needed for 2 – 3 month after delivery

19. IRON DEFICIENCY Commonest cause of anaemia worldwide
Cause of chronic ill health

20. CLINICAL FEATURES (Symptoms)
Dizziness
Headache
Weakness
Fatigue

21. CLINICAL FEATURES (signs)
Koilonychia
Glossitis

22. CLINICAL FEATURES OF IRON DEFICIENCY Angular Cheilosis or Stomatitis
Pallor
Angular Cheilosis or Stomatitis
                                        

23. Hypochromic microcytic red cells

24. Iron deficiency develops
Poor diet
Chronic blood loss or both
Intestinal parasite
Bleeding Hemorrhoids
Peptic Ulcer
Heavy menstrual losses
Closed space pregnancy
Insufficient proteins
Insufficient calories
B – vitamins. / Ascorbic acid

25. Common situation where Iron Intake is inadequate.
During infancy:
Low iron content of milk
Fe stores at birth which are usually sufficient only for first 6 months.
During rapid growth in child hood and adolescences:
Because of the need of expanding iron stores.

26. Common situation where Iron Intake is inadequate.
During reproductive period: Menstrual losses
During pregnancy, because of increased:
Maternal blood volume
Demands of the fetus and placenta
Blood losses during child birth.

27. Iron overload Total amount of Fe in body can be increased by
Excessive intake.
Abnormalities in iron absorption.
Parenteral administration of iron.
Overload iron by food alone  very difficult because of intestinal mucosal absorption.

28. Deposition of iron in the parenchymal cells of the liver.
Toxic intakes of iron reported in children and adults ingesting medicinal iron supplements.
Lethal dose for
Young Child = 3 grams
Adult = 200 – 250 mg/kg BW.
Overload can also be caused by defect in intestinal mucosa. (Hemochromatosis)
Deposition of iron in the parenchymal cells of the liver.

29. BONE MARROW FILM STAINED FOR HAEMOSIDERIN

30. Advance stage Graying pigmentation of skin Poor liver function
Liver enlargement and scaring
Pancreatic infiltration and resultant diabetes.
Myocardial disease resulting in Heart failure.

31. Things you need to know about Laboratory Testing for Iron Status
Serum ferritin most useful test
Low serum ferritin , a proof that patient is iron deficient
Normal serum ferritin does not always rule out iron deficiency
Certain conditions raise ferritin for reasons unrelated to iron status

32. LABORATORY DIAGNOSIS Elevated % transferrin saturation
Increased serum ferritin
Genetic testing for mutations of HFE gene
Evidence parenchymal iron overload on liver biopsy
Amount of iron removed by venesection

33. WHEN DOES IRON BECOME A PROBLEM?
Normally 3-5 grams of iron in the body.
Tissue damage when total body iron is 7 – 12 g
More than 12 grams is fatal
Total body iron is also increased to variable ammounts at baseline by the ineffective hematopoiesis of MDS which leads to suppressed hepcidin: which leads to excessive intestinal absorption of iron and recycling of catabolic iron from the RES cells 33