1. IRON DEFICIENCY & IDA Abdelaziz Elamin MD, PhD, FRCPCH
Professor of Child Health
College of Medicine
Sultan Qaboos University
Muscat, Oman

2. HIDDEN HUNGER
The term was coined by WHO in 1986 & refers to the problems associated with the deficiency of 3 essential micronutrients:
Iron
Iodine
Vitamin A

3. LEARNING OBJECTIVES At the end of the lecture you will be able to:
Discuss iron absorption, transport & stores
Know the burden of IDA in the world
Identify the causes & consequences of IDA
Know how to diagnose IDA
Recognize the strategies for control & prevention of IDA

4. IRON IN NATURE Iron is among the abundant minerals on earth.
Of the 87 elements in the earth’s crust, Iron constitutes 5.6% and ranks fourth behind Oxygen (46.4%), Silicon (28.4%) and Aluminum (8.3%).
In soil, Iron is 100 times more than Ca, Na & Mg and1000 times more than Zinc and 100,000 times more than Iodine.

5. IRON DEFICIENCY
Iron deficiency is the most common micronutrient deficiency in the world affecting 1.3 billion people i.e. 24% of the world population.
In comparison only 275 million are iodine deficient and 45 million children below age 5 years are Vitamin A deficient.

6. IRON DEFICIENCY /2
Iron deficiency can range from sub-clinical state to severe iron deficiency anemia.
Different stages are identified by clinical findings & lab tests.
Anemia is defined as a hemoglobin below the 5th percentile of healthy population.
Most studies showed this cutoff point to be around 11 g/dl (-2SD below the mean).

7. HB IN IDA

8. AT RISK GROUPS Infants Under 5 children Children of school age
Women of child bearing age

9. PREVALENCE OF ID Region 0-4yr 5-12yr Women South Asia 56% 50% 58%
Africa 56% 49% 44%
Latin Am 26% 26% 17%
Gulf Arabs 40% 36% 38%
Developed 12% 7% 11%
World 43% 37% 35%

10. ETIOLOGY
Inadequate intake of iron & of food, which enhances iron absorption.
High intake of inhibitors of iron absorption
Hookworm infestation.
Blood loss (heavy menses & use of aspirin & NSAID).
High fertility rate in womem.
Low iron stores in newborns.

11. DIETARY IRON
There are 2 types of iron in the diet; haem iron and non-haem iron
Haem iron is present in Hb containing animal food like meat, liver & spleen
Non-haem iron is obtained from cereals, vegetables & beans
Milk is a poor source of iron, hence breast-fed babies need iron supplements

12. IRON ABSORPTION Haem iron is not affected by ingestion of
other food items.
It has constant absorption rate of 20-30%
which is little affected by the iron balance
of the subject.
The haem molecule is absorbed intact and the iron is released in the mucosal cells.

13. IRON ABSORPTION (2)
The absorption of non-haem iron varies greatly from 2% to 100% because it is strongly influenced by:
The iron status of the body
The solubility of iron salts
Integrity of gut mucosa
Presence of absorption inhibitors or facilitators

14. INHIBITORS OF IRON ABSORPTION
Food with polyphenol compounds
Cereals like sorghum & oats
Vegetables such as spinach and spices
Beverages like tea, coffee, cocoa and wine.
A single cup of tea taken with meal reduces iron absorption by up to 11%.

15. OTHER INHIBITORS
Food containing phytic acid i.e. Bran, cereals like wheat, rice, maize & barely. Legumes like soya beans, black beans & peas.
Cow’s milk due to its high calcium & casein contents.

16. INHIBITION-HOW? The dietary phenols & phytic acids
compounds bind with iron decreasing
free iron in the gut & forming
complexes that are not absorbed.
Cereal milling to remove bran reduces
its phytic acid content by 50%.

17. Promoters of Iron Absorption
Foods containing ascorbic acid like citrus fruits, broccoli & other dark green vegetables because ascorbic acid reduces iron from ferric to ferrous forms, which increases its absorption.
Foods containing muscle protein enhance iron absorption due to the effect of cysteine containing peptides released from partially digested meat, which reduces ferric to ferrous salts and form soluble iron complexes.

18. IRON ABSORPTION (3)
Some fruits inhibit the absorption of iron although they are rich in ascorbic acid because of their high phenol content e.g strawberry banana and melon.
Food fermentation aids iron absorption by reducing the phytate content of diet

19. IRON TRANSPORT
Transferrin is the major protein responsible for transporting iron in the body.
Transferrin receptors, located in almost all cells of the body, can bind two molecules of transferrin.
Both transferrin concentration & transferrin receptors are important in assessing iron status.

20. STORAGE OF IRON Tissues with higher requirement for iron
( bone marrow, liver & placenta) contain more transferrin receptors.
Once in tissues, iron is stored as ferritin & hemosiderin compounds, which are present in the liver, RE cells & bone marrow.
The amount of iron in the storage compartment depends on iron balance (positive or negative).
Ferritin level reflects amount of stored iron in the body & is important in assessing ID.

21. IRON CYCLE IN THE BODY

22. ROLE OF IRON IN THE BODY Iron have several vital functions
Carrier of oxygen from lung to tissues
Transport of electrons within cells
Co-factor of essential enzymatic reactions:
Neurotransmission
Synthesis of steroid hormones
Synthesis of bile salts
Detoxification processes in the liver

23. DIAGNOSIS OF IDA
Clinical: symptoms (fatigue, dizziness , palpitations..etc) & signs (pallor, smooth tongue, Koilonychia, splenomegaly & dysphagia in elderly women).
Laboratory
Stainable iron in bone marrow
Response to iron supplements

24. LAB FINDINGS IN IDA Microcytic hypochromic anaemia
Low Hb level (< 11.0 g/dl)
Low MCV, MCH, MCHC
Low serum ferritin
High RWD
High iron binding capacity
High erythrocyte protoporphyrin

25. Normal Blood Film

26. MICROCYTES

27. HYPOCHROMIA

28. Consequences of Iron Deficiency
Increase maternal & fetal mortality.
Increase risk of premature delivery and LBW.
Learning disabilities & delayed psychomotor development.
Reduced work capacity.
Impaired immunity (high risk of infection).
Inability to maintain body temperature.
Associated risk of lead poisoning because of pica.

29. MANAGEMENT OF IDA Blood transfusion if heart failure is eminent
IV or IM iron in pregnant women
Oral iron 3-5 mg Fe/kg/day
Treat underlying cause
Dietary education

30. PREVENTION OF IDA Dietary modification Food fortification
Iron supplementation

31. PREVENTION OF IDA /2 Diet & nutrition education
eat more fruits and vegetable
no coffee or tea with meals
programmes should be targeted to
at risk groups
reduce phytic content of cereals and
legumes by fermentation

32. PREVENTION OF IDA /3 Short term approach: Long-term approach:
supplementation with iron tablets.
Long-term approach:
food fortification with iron either for the whole population (blanket fortification) or for specific target groups like infants. It requires no cooperation from users unlike taking iron supplements.

33. FOOD FORTIFICATION
Iron compounds used in food fortification can be divided into 4 groups
Freely water soluble (ferrous sulphate, gluconate, lactate & ferric ammonium citrate).
Poorly water soluble (ferrous fumarate, succinate
& saccharate).
Water insoluble (ferric pyrophosphate, ferric orthophosphate & elemental iron).
Experimental (sodium-iron EDTA & bovine Hb concentrate).

34. Which iron form to use?
The major factors governing the choice of iron compound include:
Bioavailability
Organoleptic problems
Cost
Safety
Ideally we should go for a safe, cheap, highly bioavailable iron, which causes no organoleptic side-effects

35. Which iron form to use?
Freely water soluble iron are the most bio-available, but causes unacceptable colour & flavour change in many foods.
Insoluble iron compounds are inert with no organoleptic effects but it is poorly absorbed
Cost-wise elemental iron is the cheapest, ferrous sulphate costs 10 times more, but most expensive is EDTA
Safety is of concern with EDTA & Bovine Hb only because of potential problems

36. COMMON PRACTICE
Ferrous sulphate is commonly used in Rx & prevention of IDA because of good absorption & high bioavailability, but it has its drawbacks
GIT disturbances & staining of teeth are frequent
Effects on fortified foods may include:
Fat oxidation & rancidity
Colour changes
Metallic taste
Precipitation

37. EXPERIMENTAL COMPOUNDS
EDTA (Ethylene Diamine Tetra-Acetate) molecule has 4 negative charges to which any metal can be attached to form stable complex. The metal incorporated into EDTA can be replaced by a metal of higher affinity or released at a certain PH.
Food is usually fortified by both Fe-EDTA & Na or Ca EDTA.

38. HOW EDTA ACTS?
Fe EDTA is stable in the acidic PH of the stomach, but dissociate in the alkaline PH of the duodenum releasing ferrous ions ready to be absorbed. while the Na-Ca EDTA dissociate in the stomach releasing Na & Ca and taking iron from the food instead to form Fe EDTA which dissociate in the duodenum.

39. ADVANTAGES OF USING EDTA
Iron absorption is 6 times greater than with ordinary methods even in the presence of inhibitors.
No need to add vitamin C or other promoters to enhance iron absorption.
No change in colour or flavour of food with EDTA even when stored for long time.

40. LIMITATIONS of EDTA USE
EDTA fortification is 7 times more expensive than ordinary fortification using iron salts.
Health care providers have little experience with this new technique.