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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.