Gill Stannard

Monday, January 19, 2009

iron deficiency anaemia

What is iron and what does it do?

Iron is involved in the formation of haemoglobin, which transports oxygen via the blood to every cell in the body.

While haemoglobin levels are ultimately lowered by iron deficiency, it is not the only type of iron that can be measured. A blood test requesting iron studies may also look at serum iron, transferrin (or iron binding capacity) or TIBC (the concentration of transferrin) and ferritin (iron storage). The first sign of iron deficiency is usually a drop in ferritin levels, followed by a fall in transferrin saturation and rise in transferrin.

We get two different types of iron from our diet haem/heme and non-haem/non-heme. The first is the most easy to absorb and use and is from animal sources, such as meat and seafood. Non-heam comes from plants such as vegetables, grains, legumes and nuts. Although non-heam iron often makes a larger amount of our daily intake (in a healthy diet), it is less bio-available.

Symptoms of iron deficiency anaemia

As iron is involved in transporting oxygen around the body, a deficiency can lead to shortness of breath, an increased heart rate, tiredness and changes in moods. It may also increase susceptibility to infections and cause a sore tongue, dizziness or even headaches. A bizarre, occasional symptom of iron deficiency is pica, which causes cravings to eat things not considered food such as soil or ice.

How do we become deficient in iron?

There are a number of reasons why iron is the most common nutritional deficiency.

The first part of the equation is the form and quantity of iron rich foods in our diet. While this is a large part of the anaemia story, it tends to get the most attention by many sources only focusing on the amount of iron in different foods. While much is made of the apparent difficulty for vegans and vegetarians to get enough iron in their diet from non-haem sources alone, it doesn’t explain why iron deficiency anaemia is also common in the carnivorous population (source).

A number of factors interfere with our absorption and utilization of dietary iron.

First we need vitamin C to help us absorb iron and a deficiency in this vitamin can result in low iron.

Other nutrients and substances can block proper uptake of iron including too much calcium and zinc, tannins (in tea and coffee), caffeine (tea, coffee, “energy drinks”), phytates (in many vegetable sources such as legumes and bran), oxalates (in spinach and rhubarb), phosvitin in egg yolk, polyphenols (in green tea, red grapes - their juice and wine) and some medicines (such as antacids and asprin).

When you look at this list of inhibitors it seems amazing we can absorb any iron at all! Zinc is abundant in some common iron rich foods such as red meat and oysters. While a vegetarian eating the cheese and spinach pie is hampered by oxalates and calcium.

The second part of the equation is how much iron our individual body needs, uses up or looses from other health issues. This is so often overlooked but is an important part of the picture in treating iron deficiency, after all why just pump more iron into the body if something is causing it to block the uptake or use up the iron too fast to replenish it?

Sometimes we just need a higher than usual amount of iron, compared to others. Endurance sport, increased physical work, growth spurts in children and teenagers, pregnancy and lactation all increase our demands on iron.

A common cause of iron loss, resulting in anaemia, is menstruation related. Periods that are heavy, long or too frequent need to be treated rather than focus on iron replenishment alone. In naturopathy we may look at hormonal normalization, uterine astringing and other nutritional deficiencies to correct the underlying problem.

Other forms of blood loss can contribute to anaemia. An internal bleed, such as in the bowel or other organs is a potentially serious problem and needs to be investigated.

Digestive problems, inhibiting iron uptake are also common. Bowel conditions like parasites such as hookworms, chronic diarrhoea, coeliac disease and Crohns can be an issue.

Other illnesses, such as hyperthyroid may contribute to anaemia.

Some drugs including antacids and other prescribed medication for treating ulcers and reflux may inhibit your uptake of iron.

How much iron do we need?

Age mg iron
0-3 months 1.7
4-6 months 4.3
7-12 months 7.8
1-3 years 6.9
4-6 years 6.1
7-10 years 8.7
Men aged 11-18 11.3
Men aged 19 and over 8.7
Women aged 11-50 14.8
Pregnant women 27.0
Postmenopausal women 8.7

Dietary sources of iron

food (quantity) [approx iron content (mg)]

oysters (85 g) [13.2]
beef liver (100 g) [6.5 ]
prune juice (1/2 c) [5.2]
parsley (50g) [4.9]
spinach (100 g) [3.0]
canned sardines (120 g) [3.24]
lean beef (100g) [3.1]
cashew nuts (50 g) [2.5]
lean lamb (100 g) [2.5]
kidney beans (1/2 c) [2.1]
lean pork (100 g) [1.4]
canned tuna (100 g) [1.0]
chicken (100 g) [0.9]

(Sources Queensland Health and University of Maryland)

Supplementing iron

Many GP’s and dieticians in Australia will primarily recommend two sources of iron – dietary in the form of meat or a supplement of ferrous sulphate (produced by pharmaceutical companies). The averages GP gets very little nutritional education in their basic training and at times rely on pharmaceutical industry advice and information via dieticians and other associations. Meat and Livestock Australia are a sponsor of the Dieticians Association of Australia while that may not directly influence the Associations advice, it is a notable commercial partnership.

Ferrous sulphate (Fefol, Ferogradumet etc) commonly causes gut upsets like constipation, nausea, vomiting and dark coloured stools. Because of this naturopaths tend to recommend a more gentle form of iron supplementation such as ferrous fumerate, with added vitamin C, or liquid forms incorporating herbs and nutrients.

Note: Some antibiotics, like tetracycline should not be taken with an iron supplement or an iron rich meal as it may reduce the drug’s effectiveness.


Vegetarian Society fact sheets on iron and raising vegetarian children.

USA Government fact sheet.

Vegan resources

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