The unknown functions of iron: Forget about Hb!!! We know that iron is important
for synthesis of haemoglobin (haem protein).
But what are the non haemoglobin functions of iron in our system???
Q. How can we the old clinicians forget about potential benefits of 1) myo globin , 2) cytochrome enzyme system & 3)
many dozens
of enzymes whose active site has an iron – sulfur center. , So, my dear member iron is not to
be equated with Hb only. –All above quoted
enzymes are synthesized from Fe . So such enzyme store,
activity and quantum are also dependent Fe in body. Yes, it is true that Hb , is an important
messenger protein which carries oxygen
to different parts of body and about 70% of body Fe is utilized in Hb synthesis.,
But we just can’t ignore rest 30% Fe in body.
.
How
many clinicians acknowledge with gratitude about the other actions of iron which is not dependent
on Hb. What I
intend to highlight is that we should not equate Fe Deficincy with poor oxygen
supply to peripheral tissues alone. Such
“ Nosh dependent essential functions of
Fe molecules:- are also essential iron
compounds in the body. Such nosh molecules include 1) Myoglobin and 2) cytochrome enzyme
system .Both these complex proteins are ,
like Hb important for life., .
In addition, there are other 3) number of enzymes
whose active site has an iron – sulfur center.
Admittedly, hemoglobin is the chief
function of Fe and Fe is abundantantly
seen in Hb protein and easily sampled of the heme proteins and accounts for > 65% of body iron. So, we come to know that iron is not for Hb synthesis only . Fe is an important part of many proteins and enzymes
that help the human body function efficiently. A) It is a component of hemoglobin the protein involved
in the movement of oxygen around
the body. It is also required for the
B) control of the cycle
of cell division and C) Cell growth and for cell
differentiation.
·
What does Myoglobin acts?
Myoglobin functions in the
transport and short term storage
of oxygen in muscle cells, helping to match the supply of oxygen
to the demand of working
muscles.
What dews other Fe dependent enzymes
act?? Ans:-Antioxidant and beneficial pro- oxidant functions: Catalase and
peroxidase are heme containing enzymes
that protect cells against the
accumulation of hydrogen peroxide ,
a potentially damaging reactive oxygen species, by catalyzing a reaction that
converts hydrogen peroxide to water
and oxygen.
· What
we need to know about Transferrin??
· Transferrin is synthesized in the liver, brain
and testes as well as other tissues. The amount of transferrin synthesized is inversely related
to the iron supply. Transferrin
is the iron transport protein that carries ferric iron between the sites
of its absorption, storage and
utilization. It binds two atoms of
ferric iron per molecule. Iron is
transferred from the intestinal mucosa to
transferrin proteins and is
carried through the blood
to peripheral tissues containing
receptor sites for transferrin.
There will be more transferrin in times
of low intake, more serum transferrin as such carrier proteins are produced so as
to optimize iron availability.
· What is Ferritin??? Ans:-Once iron enters the cell, it is chelated to a
protein known as
ferritin by the enzyme ferrochelatase. Chelation
of iron to its storage protein occurs
at the outer aspect of the
mitochondrial membrane.
· What is Haemosiderin?? Ans:- Hemosiderin is a form of denatured ferritin which
contains significantly less iron
.
· Let us recapitulate Fe
absorption: Let not prescribe Fe salts with full meals
with Phytate or brands containg Calcium ,Vit D too:
· Do we remember that people with a low
reserve of iron will absorb more iron
compared to those with
sufficient store of iron . This is the
body’s way of trying to maintain adequate
levels of iron while protecting
against iron toxicity.
Methods to
improve iron absorption . There, are however a number of methods to
improve iron absorption . Enhancing factors
1)
Ascorbic acid 2) Meat , 3) fish
4) Fermented vegetables 5) fermented say sauces 6) and other seafoods.
In fact the amount of dietary heme
iron is
especially from the meat which our Indian poor women seldom
consume. But let me warn U that ingesting of calcium along with Rin is a por
prescription.
Absorption
inhibitors : What are the Inhibiting factors
Phytate 2) Calcium 3) Soya
4)
other lower
inositol phosphates
5
)
Tannins 6) Tea : 7) Iron binding
phenolic compounds
· So what we the treating
physician do ???
One of these methods is to include
foods rich in vitamin C in the diet.
Good sources of vitamin C include citrus fruits and juices, tomatoes, strawberries, melons,
dark green leafy vegetables and potatoes. To have an effect, these foods must be
consumed along with the
iron source. The different
factors that influence iron absorption
Absorption
of Heme iron
:Factors determining
iron status of subject :
Q.. Factors controlling “Non heme
iron absorption”??
Factors determining iron status
of subjects
Amount of potentially available
non heme iron
Satiety is important part of life but that should not compromise the Fe
absorption. Balance between the
following enhancing and inhibiting
factors
Is absorbed
is meant for Hb synthesis only??? To
what extent of absorbed Fe is utilized as Hb ?? Ans:- Iron, as we understand we equate to Hb
synthesis. It is far from so. Iron has many different other roles
to play in the body . Function 1:--About 65-75%
of the body’s iron is in the blood
in the form of hemoglobin .
Hemoglobin is a protein in red blood cells that transport oxygen
to tissues in the body. Function 2: Acts as Myoglobin, the compound that carries oxygen
to the muscle cells, also requires
iron. In addition, Function 3 : part of different enzymes; iron
is involved in reactions within
the body that produce energy.
Function 4(Stored Iron) :- Any excess
iron is stored in the body as a reserve. Don’t sit idle like
Delhi Plice !!!! Identify the Individuals
who are at an Increased Risk
of Iron Deficiency
· Infants and children between the ages of 6 months
and 4 years :
Iron stores of a full – term infant
are sufficient to last for 6 months. High iron requirements are due to
the rapid growth rates sustained
during this period.
· Adolescents: Early adolescence is another
period of rapid growth . In females
the blood loss that occurs with
menstruation adds to the increased
iron requirement of adolescence.
· Pregnant women : The iron
requirement is significantly increased
during pregnancy due to increased
iron utilization by the developing
fetus and placenta , as well as blood
volume expansion.
· Individuals with chronic blood loss : Chronic
bleeding or acute blood loss may
result in iron deficiency . A
common cause of chronic blood loss and iron deficiency in developing countries
is intestinal parasitic infection. Individuals who donate
blood frequently,
especially menstruating women, may need
to increase their iron intake
to prevent deficiency because
each 500 mL of blood donated contains between 200 and 250 mg of iron .
· Individuals with celiac
disease :
Celiac disease is an
autoimmune disorder. When people with
celiac disease consume foods or products
that contain gluten, the immune
system response damages
the intestinal villi, which
may result in nutrient
malabsorption and iron deficiency
anemia.
· Individuals with Helicobacter pylori infection: H. pylori infection
is associated with iron
deficiency anemia especially in children, even in the absence of gastrointestinal bleeding .
· Individuals who have
had gastric bypass surgery
: Some types of gastric
bypass surgery increase the risk
of iron deficiency by causing malabsorption of iron among
other nutrients.
· Vegetarians : Because iron
from plants is less efficiently absorbed than that
from animal sources, it has been
estimated that the bioavailability of iron from
a vegetarian diet is only 10
% while it is 18%
from a mixed diet.
· Individuals who engage in regular intense
exercise
: Daily iron losses have been
found to be greater in athletes
involved in intense endurance
training due to the increased
microscopic bleeding from the
gastrointestinal tract or increased
fragility and hemolysis of red blood
cells,
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