Dietary iron

Dietary ironIron deficiency is a worldwide problem, even in higher income countries and is the cause of considerable poor health. If food provides insufficient iron to replace the body’s losses, stores are gradually depleted and eventually iron-deficiency anaemia results. Iron deprivation reduces the ability of blood to transport oxygen around the body with many detrimental effects, particularly in terms of cardiovascular, respiratory, neural and muscular function(1). Low iron stores, as measured by blood levels of ferritin (an iron storage protein), can cause significant effects such as tiredness, hair loss, and reduced fertility even in the presence of a normal blood count. In children, iron-deficiency anaemia can delay and sometimes permanently impair mental and motor development. Iron is, therefore, incredibly important in the diet of infants and children.

Recommended iron intakes

In the UK, mean daily dietary intakes for iron are 13mg daily in men and 10mg daily in women(2). These values exceed the Reference Nutrient Intake (RNI) for men but are below the RNI for women - the prevalence of anaemia in women is 8% and higher than that in men (3%)(3). Click here for further information on iron requirements. 

Dietary iron consumption

Iron intakes are best increased by including a variety of iron-containing foods in the diet (see table below). Dietary iron exists in two forms – haem and non-haem iron. Haem iron is found in animal foods and is particularly well absorbed and relatively unaffected by other food components. The absorption of non-haem iron, found in plant foods, is much more variable and influenced by dietary components such as tannins in tea and phytates in some cereals with which it forms insoluble complexes that make it unavailable for absorption(4). However, the absorption of non-haem iron can be enhanced by substances such as vitamin C(4).

Red meat is an important source of the highly bioavailable haem iron in the diet and supplies 17% of the total dietary iron intakes in the UK(3). Research which has evaluated associations between meat consumption and iron intake among British adults reported that people consuming less than 90g/day of red meat are three times more likely to have low iron status than people consuming more than this(5). 

Following simple dietary and lifestyle strategies can help optimise the bioavailability of iron from women's diets, helping to improve their iron status in the longer term(6).

Total iron content of selected foods (edible portion) McCance & Widdowson mg/100g
 

Food
mg/100g Food mg/100g
Calves liver, fried 12.2 Chocolate, plain 2.3
Cocoa powder 10.5 Eggs, chicken boiled 1.9
Cornflakes, fortified 7.9 Cubed lamb, grilled 1.8
Lambs liver, fried 7.7 Bread, white 1.6
Pork liver pate 6.4 Chocolate, milk 1.4
Lentils, green dried, boiled 3.5 Pork spare ribs, grilled 1.4
Lentils, semi-dried, as eaten 3.4 Lean pork tenderloin, grilled 1.3
Lean leg of lamb, roast 3.1 Lean pork leg, roasted 1.2
Sardines, in tomato source 2.9 Pork sausages, roasted 1.1
Lean braised beef 2.7 Broccoli, boiled 1.0
Red kidney beans, dried, boiled 2.5 Chicken, roast meat only, average 0.8
Lean beef rump steak, grilled 2.5 Salmon 0.8
Lean topside, roasted 2.5 Back bacon rashers, grilled 0.7
Beef burgers, grilled 2.5 Bananas 0.3
Soy sauce 2.4 Cod, fillet, baked 0.1
Bread, wholemeal 2.4    


Source: Food Standards Agency. McCance and Widdowson’s The composition of foods. Sixth Summary Edition., 2002 Cambridge: Royal Society of Chemistry.

To download the table or a graph version please click here.


For more information please visit www.meatandhealth.com   


References:
(1) McPhail P. Iron. In: Essentials of Human Nutrition. Eds Mann J, Truswell S. Oxford University Press, 3rd edition, 2007, pp125-138.

(2) Bates B, Lennox A, Swan G. National Diet and Nutrition Survey. Headline results from year 1 of the Rolling Programme (2008/2009). A survey carried out on behalf of the Food Standards Agency and the Department of Health. Available: http://www.food.gov.uk/multimedia/pdfs/publication/ndnsreport0809.pdf  and http://www.food.gov.uk/multimedia/pdfs/publication/ndnstables0809.pdf 

(3) Henderson L, Irving K, et al. The National Diet and Nutrition Survey: Adults Aged 19-64 Years. Volume 3 Vitamin and mineral intake and urinary analytes. London, The Stationery Office, 2003.

(4) Hallberg L., Brune M., Rossander L. The role of Vitamin C in Iron Absorption. Int J Vitam Nutr Res Suppl. 1989;30:103-8

(5) Gibson S and Ashwell M.  The association between red and processed meat consumption and iron intakes and status among British adults. Public Health Nutrition, 6(4), 341–350 2002.

(6) NS626 Derbyshire E (2012) Strategies to improve iron status in women at risk of developing anaemia. Nursing Standard. 26,20,51-57 Date of acceptance: October 28 2011.