VegSocUK Information Sheet THE VEGETARIAN SOCIETY ___________________________________ IRON Iron is an essential component of haemoglobin, transporting oxygen in the blood to all parts of the body. It also plays a vital role in many metabolic reactions. Iron deficiency can cause anaemia resulting from low levels of haemoglobin in the blood. Iron deficiency is the most widespread mineral nutritional deficiency both in Britain and worldwide. FUNCTIONS Iron is essential for the formation of haemoglobin, the red pigment in blood. The iron in haemoglobin combines with oxygen and transports it through the blood to the body's tissues and organs. The body contains between 3.5 and 4.5g of iron, 2/3 of which is present in haemoglobin. The remainder is stored in the liver, spleen and bone-marrow. A small amount is present as myoglobin, which acts as an oxygen store in muscle tissue. Iron deficiency can lead to anaemia. Iron stores in the body become depleted and haemoglobin synthesis is inhibited. Symptoms of anaemia include tiredness, lack of stamina, breathlessness, headaches, insomnia, loss of appetite and pallor. All these symptoms are associated with decreased oxygen supply to tissues and organs. Iron also plays an important role in the immune system, people with low iron levels having lowered resistance to infection. Research has also shown iron deficiency to be associated with impaired brain function, and iron deficiency in infants can result in impaired learning ability and behavioural problems. Iron deficiency is the most prevalent nutritional problem both in Britain and worldwide. It has been stated that 2/3 of children and women of child-bearing age in developing countries suffer from iron deficiency, 1/3 suffering from severe deficiency and anaemia. In developed countries, between 10 - 20% of child-bearing age women are said to be anaemic. Iron is the least plentiful nutrient in the typical British diet and anaemia is fairly common in the UK. DIETARY SOURCES Dietary iron exists in two different forms. Haem iron only exists in animal tissues, whilst in plant foods iron is present as non-haem iron. In a mixed omnivore diet around 25% of dietary iron is non-haem iron. Non-haem iron is less easily absorbed by the body than is haem iron. The amount of iron absorbed from various foods ranges from around 1 to 10% from plant foods and 10 to 20% from animal foods. The absorption of iron is influenced by other constituents of a meal. Phytates, oxalates and phosphates present in plant foods can inhibit absorption, as can tannin in tea. Fibre may also inhibit absorption. Vitamin C greatly increases the absorption of non-haem iron. Foods rich in vitamin C include citrus fruits, green peppers, and fresh leafy green vegetables. Citric acid, sugars, amino acids and alcohol can also promote iron absorption. Iron absorption can also be influenced by the amount of iron in the diet. Lowered levels of iron in the diet result in improved absorption. Good sources of iron for vegetarians include wholegrain cereals and flours, leafy green vegetables, blackstrap molasses, pulses such as lentils and kidney beans, and some dried fruits. Good sources of iron (single servings) Spinach, boiled (100 g or 3 1/2 oz.) 4.0 mg Chick peas (200 g or 7 oz.) 6.2 mg Baked beans (225 g or 8 oz.) 3.2 mg Bran flakes (45 g or 1 1/2 oz.) 18.0 mg Muesli (60 g or 2 1/4 oz.) 2.76 mg 8 Dried apricots (50 g or 1 3/4 oz) 2.1 mg 4 Dried figs (60 g or 2 oz) 2.1 mg Black treacle (35 g or 1 1/4 oz) 3.2 mg Fair sources 1 slice wholemeal bread (40 g) 1.0 mg Egg, boiled 1.3 mg Brown rice (200 g or 7 oz) 0.9 mg Avocado (75 g or 2 2/3 oz) 1.1 mg Asparagus (125 g or 4 2/3 oz) 1.1 mg Broccoli, boiled (100 g or 3 1/3oz) 1.0 mg Peanut butter (20 g or 2/3 oz) 0.5 mg Poor sources Cow's milk (1/2 pint) 0.14 mg Hard cheese (30 g or 1 oz) 0.12 mg Yoghurt (150 g or 5 1/4 oz) 0.36 mg Banana (120 g or 4 1/4 oz) 0.48 mg Margarine (7 g or 1/4 oz) 0.02 mg Despite iron from plant foods being less readily absorbed research has shown that vegetarians are no more likely to suffer from iron deficiency than non-vegetarians. Draper & Wheeler (1989) have stated there is no indication of increased prevalence of iron deficiency amongst vegetarians. Anderson (1981) found the iron status of long-term vegetarian women to be adequate, despite a high intake of fibre and phytate. Anderson, B. et al. (1981). The iron and zinc status of long-term vegetarian women. American Journal of Clinical Nutrition v.34 (6) p.1042-1048. Draper, A. & Wheeler, E. (1989). The diet and food choice of vegetarians in Greater London. Centre of Human Nutrition, London. REQUIRED INTAKES The old Recommended Daily Amounts (RDA's) have now been replaced by the term Reference Nutrient Intake (RNI). The RNI is the amount of nutrient which is enough for at least 97% of the population. Reference Nutrient Intakes for Iron , mg/day. Age RNI 0 to 3 months 1.7 mg 4 to 6 months 4.3 mg 7 to 12 months 7.8 mg 1 to 3 yrs 6.9 mg 4 to 6 yrs 6.1 mg 7 to 10 yrs 8.7 mg Men 11 - 18 yrs 11.3 mg Men 19 + yrs 8.7 mg Women 11 - 49 yrs 14.8 mg Women 50 + yrs 8.7 mg In women of child-bearing age, loss of iron from menstruation of blood adds considerably to iron need. These losses can be highly variable. Around 10% of women of child-bearing age will need more iron than is indicated. In men, post-menopausal women, and children iron is efficiently conserved by the body. Iron in haemoglobin is recycled and the amount of iron lost from the body is very small. Infants and children need extra iron to increase blood volume and muscle tissue. Extra iron is also required during pregnancy and breast feeding. MEAL PLAN Sample one day's meal plan to meet the RNI of 14.8 mg for a women aged 11 to 49 years. Breakfast Bowl of muesli with milk 2.76 mg 1 slice of toast 1.0 mg Lunch 2 slices of wholemeal bread 2.0 mg Peanut butter (20 g or 2/3 oz) 0.5 mg 1 banana 0.5 mg Evening meal Brown rice (200 g or 7 oz) 0.94 mg Chick peas (200 g or 7 oz) 6.2 mg Broccoli (100 g or 3 1/3 oz) 1.0 mg Total iron intake 14.9 mg ___________________________________ // This article is copyright to the Vegetarian Society (UK), but may be freely copied for non-commercial use provided it is kept intact, not altered and these lines are included. For futher information contact: The Vegetarian Society, Parkdale, Dunham Road, Altrincham, Cheshire WA14 4QG, England. Tel: (England) 061 928 0793 email: vegsoc@vegsoc.demon.co.uk // [The text of this file was obtained from the Vegetarian Society (UK) in March 1995.]