February 19th, 2013
Iron is a mineral, that helps transport oxygen around the body with the aid of red blood cells called haemoglobin. It is predominantly stored in ferritin complexes in the liver, bone marrow and spleen. Most healthy people have 4-5 g of iron in their bodies.
Primary Iron Deficiency tends to affect:
- Vegetarians, the elderly, and people with protein calorie malnutrition
- It is also more common during periods of growth, due to the expansion of blood volume, which occurs in infancy, adolescence and pregnancy
- It is the most common cause of anaemia, although this is the last stage of iron deficiency
- Enzymes involved in energy production and metabolism requiring iron are the first to be affected by low iron stores (Braun and Cohen, 2005), often leaving people feeling tired for months. If you are concerned about your iron and energy levels, testing your serum ferritin levels is the best way to determine body iron stores.
Secondary Iron Deficiency is a result of:
- blood loss, gastrointestinal problems affecting absorption (coeliac disease), and increased destruction of red blood cells
- excessive menstruation is the most common cause
- Iron deficiency is the most common deficiency in the world
Some Deficiency Signs and Symptoms
- fatigue and lethargy
- cardiovascular and respiratory changes
- pale inner eyelids and palm creases
- pale nail bed
- brittle hair
- decreased resistance to infection
- poor mental and motor function
- reduced thyroid function
- difficulty maintaining body temperature in the cold
Vegetarians and Iron Stores
- The Dietary Reference Intakes recently suggest that vegetarians need to increase dietary iron by 80% to compensate for the lower iron bioavailability of 10% from a vegetarian diet (Hunt, 2003).
- The recommendations of 33 mg of iron for a vegetarian woman of childbearing age is difficult to meet with foods alone, especially when most assessments of their dietary intake fall in the range of 11-18 mg/d (Hunt, 2003).
- However the vegetarian food guide pyramid calculated on a (2000 kcal) diet would be most beneficial for vegetarians trying to obtain 32-36 mg Fe/d (Hunt, 2003).
- Haeme iron – found predominantly in animal sources: lean red meat, liver, poultry, fish, oysters, clams, shellfish. It is absorbed 2-3 times better than non-haeme forms.
- Non – haeme iron – found in plant and dairy products: nuts, legumes, vegetables, fruit, dried fruit, grains and tofu.
Factors that Enhance Non-Haeme Iron Absorption
- Acids – 20mg of ascorbic acid has been shown to increase levels by 39% (Braun & Cohen, 2005). Pizzorno & Murray, (1998) suggest 500 mg of Vitamin C with each meal.
- Red meat increase absorption by 85% (Braun & Cohen, 2005).
Factors that Inhibit Non-Haeme Iron Absorption
- Iron from a vegetarian diet is likely to be substantially less available for absorption because of the different form of iron and other constituents that inhibit iron absorption
- Polyphenols found in tea and coffee, red and white wine
- Phytic acid (whole grains), and oxalic acid (spinach, chocolate, berries)
- Calcium (milk) can reduce absorption by up to 70%, also other dairy products and eggs
- Zinc competes for absorption
- Achlorhydria and antacid use
- There are many drug interactions with iron, tetracycline antibiotics, antacids and L-dopa to name a few
Recommended Daily Allowance
Children (1-11 years) 6-8 mg
Children (12- 18 years) 10-13 mg
Men >19 years 7mg
Women (19 to menopause) 12-16 mg
After menopause 5-7 mg
Before taking any iron supplements get your iron levels tested and consult your naturopath or doctor. Supplements are used to treat or prevent iron deficiency but need to be used with caution because excess use can be dangerous and lead to organ damage.
Inappropriate iron supplementation in children can inhibit growth in non deficient children
Braun, L, & Cohen, M. 2005 Herbs and Natural Supplements An Evidenced Based Guide, Elsevier, Australia
Hunt, J 2003 ‘Bioavailability of Iron, Zinc, and Other Trace Minerals from Vegetarian Diets’ AJCN, Vol 78, No 3, 633s-639s, viewed 27th February 2007 http://www,ajcn.org