Iron Deficiency and Anaemia

by Meredith Beil BPharm MNutr & Alice Downing APD, MDiet & BHumNutr
Dietary Iron
The mineral iron has many
essential functions in the human body. These
essential functions include the generation of energy in our cells, the formation of haemoglobin in red blood cells to transport oxygen throughout the
body and muscles cells, and immune system function.
Consequences
of Iron Deficiency
- Tiredness, fatigue, irritability, loss of appetite and
pica (eating non-food substances)
- Reduced attention span, poor learning and impaired
performance
- Reduced exercise stamina and muscle strength
- Impaired body temperature regulation (sensitivity to
cold)
- Reduced immune system functioning and susceptibility
to infection
Susceptibility to Iron Deficiency
Iron deficiency is one of the most
common nutrient deficiencies in Australia. Iron deficiency is particularly
prevalent in infants, toddlers and
pre-schoolers; as well as adolescents
during periods of rapid growth; and women during their reproductive years. A baby’s iron stores become depleted by
around six months of age, so sufficient iron-rich foods need to be introduced
to support development. Young children and adolescents often do not meet minimum
dietary iron requirements due to the increased demand during periods of rapid
growth. Adolescent females and young
women require significantly more dietary iron than their male counterparts,
whilst a pregnant woman’s daily requirement of iron are triple that of
men. It is difficult for pregnant women
to obtain sufficient iron through dietary sources and most require a daily iron
supplement on recommendation of their doctor.
Recommended
Dietary Intake of Iron (Per Day)
AGE
|
RDI (mg)
|
AGE
|
RDI
(mg)
|
7-12
months
|
11mg
|
Adult
Male 18 years
|
8mg
|
1-3
years
|
9mg
|
Female
19-50 years
|
18mg
|
4-8
years
|
10mg
|
Female
>51 years
|
8mg
|
9-13years
|
8mg
|
Pregnancy
|
27mg
|
Male
14-18 years
|
11mg
|
Lactation
14-18 years
|
10mg
|
Female
14-18 years
|
15mg
|
Lactation
19-50 years
|
9mg[AD2]
|
Common Causes
of Iron Deficiency and Anaemia
·
Diets
low in iron-rich foods (vegetarian/vegan diet, low energy diets, fad diets,
disordered eating practices, very high carbohydrate diets)
·
Pregnancy
or recent pregnancy
·
Intensive
training programs (athletes have higher
requirements and suffer higher losses)
·
Impaired
absorption or bleeding in the gastro-intestinal tract (Irritable Bowel Syndrome
or Coeliac Disease)
·
Medications
that reduce acid production in the stomach (iron requires an acidic environment
for absorption)
·
Medications
such as tetracycline and antacids that bind with iron (preventing absorption)
·
Blood
loss; or blood donations where iron stores are not adequate
If iron deficiency is not treated adequately it may
progress to the more serious condition of anaemia in which iron stores are
depleted and there are insufficient healthy red blood cells for transporting
oxygen.
Dietary Sources of Iron
Dietary iron is present as either haem or
non-haem iron, with haem-iron being 2-3 times more easily absorbed than
non-haem iron. Haem iron is found only
in animal products and constitutes approximately 40% of the iron in these
foods. Non-haem iron is present in plant foods such as green leafy vegetables,
legumes, nuts, wholegrain breads and iron-fortified products. Although non-haem iron is found in many foods,
absorption of non-haem iron is influenced by other dietary components.
Major Dietary
Sources of Iron
Food
|
Iron (Mg /
Serve)
|
Serving
Size
|
Lamb (lean, cooked)
|
5.4
|
100g
|
Beef (lean, cooked)
|
3.4-3.7
|
100g
|
Pork (lean, cooked)
|
1.5
|
100g
|
Chicken (lean, cooked)
|
0.8-1.2
|
100g
|
Fish
|
0.8-1.2
|
100g
|
Egg
|
0.9
|
55g
|
Green leafy
vegetables
|
0.8-3.2
|
100g eg ½ cup
broccoli
|
Iron
fortified breakfast cereals
|
3.0
|
30g eg 2
whole wheat biscuits
|
Legumes
|
2.5
|
125g eg 2/3
cup lentils
|
Tofu, firm
|
2.9
|
100g
|
Nuts
|
2.5
|
50g eg 25
cashews
|
Dried
apricots
|
1.6
|
50g eg 10
halves
|
Seeds
|
0.7
|
15g eg 1 tbsp
sunflower seeds
|
Strategies for enhancing the absorption
of non-haem iron include
the use, as well as the avoidance of, certain combinations of foods.
To
enhance
the absorption of the iron in foods:
- Add a small
portion of lean beef or lamb, to a salad, sandwich or stir-fry
- Eat vitamin C
containing foods with meals (citrus fruit, tomato, capsicum)
Food
components and combinations that reduce the absorption of iron:
- Tea, coffee
and red wine are best consumed away from meal times (tannins and
polyphenols bind to iron)
- Dietary
calcium, calcium supplements taken with dietary iron , calcium and iron
supplements taken simultaneously (Take
iron and calcium supplements separately)
Supplementation
Iron supplements should
only be taken on recommendation from a doctor who has performed blood tests and
investigated possible causes of low iron. It takes time to recover depleted
iron stores. Recovery from anaemia can take months or years using dietary iron
and supplementation, depending on the severity. Always optimise dietary iron
intake in combination with iron supplementation.
If your iron levels are
low, remember it is the combinations of the foods you consume and the frequency
of your iron consumption that is most important. Eating a big steak on one
occasion will not improve your iron levels.
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