1. ROLE OF IRON IN HUMAN HEALTH
Arun Malik and Hariom Yadav
NATIONAL AGRI-FOOD BIOTECHNOLOGY INSTITUTE, MOHALI , PUNJAB, INDIA

2. WHY DO WE NEED IRON Iron is a mineral found in every cell in the body.
It is vital for both physical health and
mental well-being.

3. Iron has three main functions :
carrying oxygen from the lungs to the rest of
the body.
maintaining a healthy immune system.
(Body protects itself from antigens, which includes virus, bacteria and
foreign substances that make sick)
aiding energy production.
(Iron is constituent of several enzymes including : iron catalase,
peroxidase, and cytochrome enzymes)

4. INSUFFICIENT DIETARY IRON CAN RESULT IN IRON DEFICIENCY
fatigue
lethargy
more frequent infections
reduced resistance to cold
impaired learning
Hypoferrimia

5. TYPES OF IRON There are two types of iron in food:
Heme iron, derived from the hemoglobin and myoglobin found in meat tissue
Non-heme iron, derived mainly from cereals,
legumes, fruit and vegetables.

6. HEME IRON meat is approximately 40% heme iron and 60% non-heme
Heme iron is found only in animal foods. The iron in
meat is approximately 40% heme iron and 60% non-heme
iron. Plant foods do not contain any heme iron .
Heme iron is well absorbed and relatively unaffected by other
factors .
It is influenced to some extent by the body’s iron stores.
The average absorption of heme iron in meat is about 25%.

7. NON-HEME IRON It is not as well absorbed as heme iron and is affected
Non-heme iron is found in plant foods.
It is not as well absorbed as heme iron and is affected
by both the iron status of an individual, and components
in foods eaten at the same time.
Absorption of non-heme iron can vary from under 1% in
an individual with replete stores to 20% in an individual
with depleted iron stores .
Generally non-heme iron absorption is less than 5%.

8. VITAMIN C IMPROVE NON-HAEM IRON ABSORPTION
Vitamin C can increase the absorption of non-haem
iron by two to three times.
There is a dose-related effect; the more vitamin C in a meal, the greater
the iron absorption - up to a limit of around 100mg vitamin C .
Vitamin C is found in fruit and vegetables. Both heat and air reduce
vitamin C content, so care should be taken when cooking and storing fruit
and vegetables.

9. FACTORS AFFECTING NON-HAEM IRON ABSORPTION
IMPROVE ABSORPTION
INHIBIT ABSORPTION
CAULIFLOWER
TANNINS IN TEA
TOMATOES
DIETARY FIBRE
KIWIFRUIT
SOY PROTEINS
MEAT, FISH, POULTRY
PHYTATES IN WHOLEGRAINS
TAMARILLOS
POLYPHENOLS
CITRUS FRUIT (ORANGES, GRAPES)
OXALATE

10. IRON SUPPLEMENTS Iron supplements should only be used when advised
by a dietitian or prescribed by a medical practitioner for
diagnosed iron deficiency.
Iron supplements should be used
cautiously as they may interfere with the absorption of
other nutrients such as zinc and calcium.

11. IRON ABSORPTION IN HUMAN BODY

12. LIBERATED WITH IN ENDOSOME
HEME IRON UPTAKE
HEME IRON
HEME IRON TRANSPORT
ENDOCYTOSIS
FERROUS IRON
LIBERATED WITH IN ENDOSOME

13. NON-HEME IRON UPTAKE FERRIC IRON REDUCED BY ASCORBIC ACID
INCLUDE DUODENAL CYTOCHROME B
FERROUS IRON
TRANSFERRIN
FERROPORTIN
HEPHAESTIN

14. HEPCIDIN REGULATES IRON ABSORPTION
Hepcidin is 25 amino-acid peptide hormone.
Hepcidin is synthesized by hepatocytes.
Hepcidin binds to ferroportin1 and causes
its internalization and degradation thereby
decrease iron transfer to blood.
Hepcidin function to regulate(inhibit)
iron transport across gut mucosa there by
preventing normal iron level.

15. HOW HEPCIDIN REGULATES IRON ABSORPTION

16. Hepcidin regulation by Inflammation
IL-6 a prominent inducer of hepcidin, through STAT-3 dependent transcriptional mechanism.
Other cytokines may also induce hepcidin independent of IL-6.
Macrophage also express hepcidin in response to
micobial stimulation.
Hepcidin may function in autocrine manner to degrade macrophage ferroportin,
causing local retention of iron in macrophages.

17. EFFECT OF MUTATION OF SPECIFIC PROTEINS
IRON OVERLOAD
IRON DEFICIENCY
Hypotransferrinanemia - recessive
TMPRSS6 mutation - IRIDA
HFE gene mutation
Ferroportin mutation – autosomal dominant
Hepcidin mutations
Hemojuvelin mutations
H ferritin mutation - dominant

19. HUMAN DISEASE ASSOCIATED WITH IRON
CARDIOVASCULAR DISEASE
HEMOCHROMATOSIS PROTEIN HFE
THE FRIEDRICH’S ATAXIA PROTEIN
MELANOTRANSFERRIN

20. CARDIOVASCULAR DISEASE
Heme iron are associated with cardiovascular diseases(CVD) risk.
Such as saturated fats or other dietary and lifestyle factors associated with meat intake.

21. HEMOCHROMATOSIS PROTEIN HFE
Hereditary hemochromatosis is inherited disorder that results from an excess accumulation of iron in many organs which is manifested by liver cirrhosis, cardiomyopathy, diabetes mellitus, arthritis, skin pigmentation and if left untreated death.
The gene responsible for hereditary hemochromatosis is closely linked to locus for the human leukocyte antigens and has been identified as major histocompatibility complex-encoded class-1 like HFE.
Hereditary hemochromatosis is more prevalent than other inherited diseases such as cystic fibrosis, sickle cell anemia, phenylketonuria and Tay-Sachs disease.

22. THE FRIEDRICH’S ATAXIA PROTEIN
Farataxin is mitochondrial protein which involved in mitochondrial iron homeostasis.
Farataxin deficiency is due to hyper-expansion of polymorphic GAA trinucleotide repeat which inhibits transcription and falls in levels of mature faratxin mRNA.
Farataxin deficiency in patients leads to develop Friedrich’s ataxia which is a progressive neurological disorder and cardiomyopathy and finally leads to death.

23. MELANOTRANSFERRIN
Melanotransferrin reported to expressed in amyloid plaques in brain of patients with Alzheimer’s disease.
Melanotransferrin mRNA widely expressed in tissue and also in salivary glands.
Levels of melanotransferrin mRNA do not change in presence or absence of an iron chelators or iron source.
Functional studies shown that melanotransferrin transports iron from iron-citrate complexes but not from iron-transferrin complex.
Melanotransferrin has minor role in iron uptake from iron citrate complexes.

24. IRON BIOAVAILABILITY IN VEGETABLES
IRON IN /mg
Mushroom, pleurote
1.74
Potatoes
0.76
Cabbage, Collards
0.19
Cabbage, Green
0.59
Roasted Pumpkin and Squash Seeds 15
Spinach
2.71
Sesame Butter(Tahim) and Seeds
14.8
Sundried Tomatoes
9.1
Dried Apricot
2.2
Lentils
6.20

25. IRON BIOAVALABILITY IN FRUITS
IRON IN/mg
Apples, without skin
0.07
Blackberries
0.57
Dates
1.15
Pears, without skin
0.25
Pineapple
0.37
Raspberries

26. IRON BIOAVALABILITY IN GRAINS
SERVING
IRON IN /mg
Wheat Flour, White Cake, Enriched
1 cup
10.03
Wheat, Soft White
9.02
Wheat, Hard White
8.76
Sorghum
8.45
Corn flour, Masa, Enriched White
8.22
Corn flour, Masa, Enriched Yellow
Millet
6.02
Oats
7.36
Quinoa
2.36
Rice Bran, crude
21.88

27. MORE HEME IRON RICH FOODS
Meat
IRON IN/mg
Beef Lean Chuck
2.9mg
Turkey Meat(Dark)
2.3mg
Chicken Leg(Roasted)
1.3mg
Tuna(Bluefin)
Halibut
Pork Chops(Loin)
1mg
White Tuna
0.9mg
Shrimp(Prawns/Camarones)
Liver
30.5mg
Clams, Oysters and Mussels
28mg

28. RECOMMENDED DIETARY IRON INTAKE
IRON mg per Day
Infants (7-12 months) 11
Children (1-13 years)
8-10
Boys (14-18 years)
Girls (14-18 years) 15
Women (19-50 years) 18
Pregnant Women 27
Breastfeeding Women
9-10
Women over 50 years 8
Men over 19 years

29. CONCLUSION Heme and non-heme iron are absorbed differently.
Meat, fish, poultry and vitamin C improve the absorption
of non-heme iron.
Tannin, oxalate, phytates and dietary fibre all reduce the
absorption of non-heme iron.