Iron
DEFINITION
Iron is an essential nutrient that performs a wide range of
functions in the body, including assisting in the transport of
oxygen via the blood.
functions in the body, including assisting in the transport of
oxygen via the blood.
DESCRIPTION
Iron is an essential part of haemoglobin, a substance inside
red blood cells that is designed to carry oxygen around the body.
It is also used to form myoglobin, which is similar in function to
haemoglobin and delivers oxygen to skeletal muscles. Iron is also
an essential part of many enzymes. Enzymes are substances that
speed up chemical reactions within the body. Iron is a component of
the enzymes that break down drugs and other foreign, potentially
toxic chemicals before they can be excreted by the body. Excess
dietary Iron intake is toxic and causes vomiting, diarrhoea and
damage to the intestines. The genetically inherited disease
haemochromatosis is characterised by excess absorption of Iron from
the intestines. It can cause tissue damage as the excess Iron is
deposited in the body organs.
red blood cells that is designed to carry oxygen around the body.
It is also used to form myoglobin, which is similar in function to
haemoglobin and delivers oxygen to skeletal muscles. Iron is also
an essential part of many enzymes. Enzymes are substances that
speed up chemical reactions within the body. Iron is a component of
the enzymes that break down drugs and other foreign, potentially
toxic chemicals before they can be excreted by the body. Excess
dietary Iron intake is toxic and causes vomiting, diarrhoea and
damage to the intestines. The genetically inherited disease
haemochromatosis is characterised by excess absorption of Iron from
the intestines. It can cause tissue damage as the excess Iron is
deposited in the body organs.
DEFICIENCY
Iron deficiency is the most common nutritional deficiency in
the world. It can be caused by inadequate dietary Iron intake,
deficiencies in the ability to absorb iron or by blood loss. The
symptoms and signs of Iron deficiency include iron deficiency
anaemia, where the red blood cells are abnormally small and pale
and have a low content of haemoglobin. This can cause pallor,
fatigue, breathlessness on exertion, palpitations, dizziness and
headache. Other signs include cracks in the corners of the mouth,
sore tongue and brittle fingernails. Often there are no symptoms
and the deficiency may be discovered during routine blood tests.
Vague symptoms of tiredness are common. Iron deficiency in young
children can cause behavioural problems such as reduced attention
span and reduced cognitive performance that may be
irreversible.
the world. It can be caused by inadequate dietary Iron intake,
deficiencies in the ability to absorb iron or by blood loss. The
symptoms and signs of Iron deficiency include iron deficiency
anaemia, where the red blood cells are abnormally small and pale
and have a low content of haemoglobin. This can cause pallor,
fatigue, breathlessness on exertion, palpitations, dizziness and
headache. Other signs include cracks in the corners of the mouth,
sore tongue and brittle fingernails. Often there are no symptoms
and the deficiency may be discovered during routine blood tests.
Vague symptoms of tiredness are common. Iron deficiency in young
children can cause behavioural problems such as reduced attention
span and reduced cognitive performance that may be
irreversible.
SOURCES
There are two nutritional forms of Iron: haem Iron and
non-haem Iron. Haem Iron is much more easily absorbed by the body
than non-haem Iron, although the absorption of non-haem Iron can be
improved when food is eaten with vitamin C and protein. Sources of
haem Iron include meat, poultry and fish. Non-haem iron is found in
cereals, vegetables, pulses, beans and fruit. Other substances that
are present in foods can decrease the amount of non-haem Iron that
the body absorbs. These substances include calcium, soy products
and phytates (found in all grains, seeds, nuts, vegetables and
fruit). Substances called tannins, which are found in tea, coffee
and cocoa, also inhibit Iron absorption. Tea and coffee should not,
therefore, be consumed with a meal as they strongly decrease the
amount of Iron absorbed from the food.
non-haem Iron. Haem Iron is much more easily absorbed by the body
than non-haem Iron, although the absorption of non-haem Iron can be
improved when food is eaten with vitamin C and protein. Sources of
haem Iron include meat, poultry and fish. Non-haem iron is found in
cereals, vegetables, pulses, beans and fruit. Other substances that
are present in foods can decrease the amount of non-haem Iron that
the body absorbs. These substances include calcium, soy products
and phytates (found in all grains, seeds, nuts, vegetables and
fruit). Substances called tannins, which are found in tea, coffee
and cocoa, also inhibit Iron absorption. Tea and coffee should not,
therefore, be consumed with a meal as they strongly decrease the
amount of Iron absorbed from the food.
Iron is a component of many dietary supplements, where it is
usually in the form of what is called ‘ferrous’ iron. The other
form that Iron can exist in is ‘ferric’ iron. Ferrous and ferric
are terms used to describe the positive charge that Iron has.
Ferrous Iron is the form of Iron that is best absorbed by
humans.
usually in the form of what is called ‘ferrous’ iron. The other
form that Iron can exist in is ‘ferric’ iron. Ferrous and ferric
are terms used to describe the positive charge that Iron has.
Ferrous Iron is the form of Iron that is best absorbed by
humans.
DOSAGE
The recommended dietary intake (RDI) for Iron is 7 mg per day
for adult males and 12-16 mg per day for adult females, although
women that are pregnant require and additional 10 to 20 mg per
day.
for adult males and 12-16 mg per day for adult females, although
women that are pregnant require and additional 10 to 20 mg per
day.