Iron, a precious mineral, involves in many physiological processes in our body. Most of the iron in the body is a component of the proteins: Hemoglobin – in red blood cells and Myoglobin – in muscle cells. Body tissues constantly need oxygen to keep the cells cleaned and to function efficiently. Iron helps your cells “Breathe!” Yes, hemoglobin carries oxygen from lungs to tissues throughout the body and myoglobin holds and stores oxygen in the muscles for their use. Iron is also a part of enzymes, particularly those involved in energy metabolism.
Our body hoards iron in liver, spleen and bone marrow. It is a precious mineral to be hoarded!
Despite the fact that iron is the fourth most abundant element in the earth, iron deficiency is the world’s most common cause of anemia. The most common dietary deficiency worldwide is iron that affects women and children even more! Decreased dietary iron, decreased iron absorption, or blood loss is the major cause of iron deficiency anemia. Celiac disease ( sprue), an immune reaction to eating gluten, have shown to impair the iron absorption. Significantly iron deficiency is linked with decreased immune function and resistance to infection, diminished work capacity and increased risk of delivery of pre-term and low birth weight infants. Lead, a pernicious metal, inhibits the iron absorption. It not only influences anemia, it even impairs cognitive development, in children!
The Estimated Average requirements of iron
Teenage boys |
Teenage girls |
Women |
Older |
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women | Men | ||||||||
Age | 14-18 yrs | 14-18 yrs | Pregnant | Breast feeding | 19-50 yrs | Pregnant | Breast feeding | 51+ yrs | 19+ yrs |
Iron/day | 11 mg | 15 mg | 27 mg | 10 mg | 18 mg | 27 mg | 9 mg | 8 mg | 8 mg |
Growing children require sufficient iron, for their increasing red cell mass. People who engage in regular intense exercise like distance runners, female athletes, and vegetarian athletes need more iron in their diet. Lack of iron, can profoundly affect the physical activity performance, by reducing the oxygen flow to the exercising muscles!
Heme iron, found primarily in animal foods, is absorbed more efficiently (35%) from a single meal and its absorption is not affected by any other nutrients. The richest is in the liver, followed by oysters, red meat from luscious beef & lamb and dark meat of poultry (duck and goose). Red meat, and liver are good sources of iron, but are also high in cholesterol and saturated fat. Their intake should be limited, 4-6 oz/day, to promote the heart health.
Iron from plant sources and egg yolks are considered non-heme iron that takes more effort and energy for the body to absorb. Dark green, leafy vegetables, dried fruits, iron-enriched cereals, beans, lentils, chickpeas, are good plant sources of iron. You can get 0.55 mg of iron from 60 g cooked asparagus and 1.05 mg of iron from 150 g/ 1 cup, sauteed, broccoli in few minutes!
Dried-figs, apricots, raisins, quinoa, oats and rye are also considered as good source of iron.
Description | Weight (g) | Common measures | Iron content per measure |
Apricot-dried | 35 | 10 halves | 0.93 mg |
Figs- dried | 92 g | 5 figs | 1.92 mg |
Raisins | 14 g | 1 packet | 0.26 mg |
Almonds | 28.35 g | 10oz/24nuts | 1.05 mg |
Walnuts | 28.35 g | 10oz/14halves | 0.82 mg |
Beet green | 144 g | 1 cup | 2.74 mg |
Beet-cooked | 50 g | 1 beet | 0.40 mg |
Spinach-cooked | 180g | 1 cup | 6.43 mg |
Mustard greens- cooked | 140 g | 1 cup | 0.98 mg |
Mung beans-sprouted | 104 g | 1 cup | 0.95 mg |
Peas | 160 g | 1 cup | 3.15 mg |
Rice- brown/long- grain | 195 g | 1 cup | 0.82 mg |
Beef- top sirloin | 85 g | 3 oz | 1.47 mg |
Oyster-raw | 84 g | 6 medium | 3.87 mg |
Scallop | 85 g | 3 oz | 1.38 mg |
To know the amount of iron in other foods, please click: http://ndb.nal.usda.gov
The bioavailability of iron from some of the iron-rich plant foods are poor because other compounds render it, nonabsorbale. Only 2-20% of iron from plant sources is absorbed in a single meal. Phytates, oxalic acid, tannins and antacids block the absorption of iron. For example, spinach is a good source of iron. But it also contains high levels of oxalic acid bound to iron! Consequently, the bioavailability of iron in spinach is significantly less than the amount it actually contains! Phytates are prominent in wheat and tannins are prevalent in teas (non-herbal).
Women, 19-50yrs, consuming a vegetarian diet may need almost 33mg of iron per day, for the bioavailability of iron from plant food sources is much lower when compared to animal food sources!
You will be surprised to learn that the bone-mineral, calcium, inhibits the absorption of iron!
Worried, how to increase your iron level?
Reducing calcium intake doesn’t sound good, for it is needed to increase bone mass to reduce the risk of osteoporosis. It is wise, not to mix calcium and iron rich food in the same meal. A descent separation of calcium and iron rich food will help to improve the iron nutrition.
Cooking spinach, for 2-3 mins, will help reduce the oxalate. Soaking, fermenting and sprouting will help reduce the total phytates. By soaking beans and nuts for 24 hrs followed by cooking you can reduce the phytates level by 50%!
Following a healthy diet including iron-rich foods, and pairing foods for optimal absorption, can help you increase your iron levels, naturally! Yes, iron absorption depends on the type of staple used.
Ascorbic acid (Vitamin C) favours iron absorption in the intestine!
Vitmain C has been shown repeatedly to augment the absorption of non-heme iron in human. Incorporating vitamin C in the form of tomatoes, orange, lime juice, berries, to your meal can help increase the absorption of iron. Make sure that you consume fruits as a source of Vitamin C, minimum 25mg with each meal, to captivate this essential mineral.
Garnish your green salad with toasted nuts/dried fruits and squeeze lime juice over, to balance and increase the absorption of iron.
B vitamins are important for the production of healthy red cells.
- Pyridoxin, vitamin B-6 found in whole grains, bananas, carrots, cabbage helps the blood to carry oxygen and maintain blood sugar levels.
- Riboflavin, Vitamin B-2 in liver, fish, egg, milk, wholegrains and fortified cereals help enhance the response of hemoglobin to iron.
- Cobalamin, vitamin B-12,found in cheese, dairy products, eggs, liver, meat, oysters, salt-water fish, helps in the blood formation. Few foods of vegetable origin like seaweed and tempeh, provide small amounts of B-12. The probiotics in yogurt and other fermented milk products help to produce this B-12 vitamin, right down inside your intestines. Sounds interesting and great, especially for vegans!
After the 1st year, children should be given a varied diet that is rich in sources of iron, B vitamins and vitamin C
Balancing your meal with wholegrains, meat/beans, fruits & vegetables, nuts and probiotic drinks will preclude the negative iron balance. Fruits improve the iron status and the bioavailability, for it is rich in vitamin C. Red meat & oyster are not only a good source of heme iron, also the best form for storing in the body, that help absorb the non-heme iron. It is wise to avoid coffee, tea, milk, soy products in combination with iron-rich/fortified foods.
Iron is more precious than Gold!
References
- James D Cook and Manju B Reddy. Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet. Am J Clin Nutr January 2001 vol. 73 no. 1 93-98
- John Beard and Brian Tobin. Iron status and exercise. Am J Clin Nutr August 2000 vol. 72 no. 2 594s=597s
- Ann Gleerup, Lena Rossander- Hulthen, Elsiabeth Gramatkovski, and Leif Hallberg.Iron absorption from the whole diet: comparison of the effect of two different distribution of daily calcium intake. Am J Clin Nutr January 1995 vol. 61no.1 97-104
- K Madhavan Nair & Vasuprada Iyengar. Iron content, bioavailabilty & factors affecting iron status of Indians. Indian J Med Res 130, November 2009, pp 634-645
- Sandrine Peneau, Luc Dauchet, Anne-Claire Vergnaud, Carla Estaquio, Emmamnuelle Kesse-Guyot, Sandrine Bertrais, Paule Latino-Martel, Serge Hercherg, and Pilar Galan. Relationship between iron status and dietary fruit and vegetables based on their vitamin C and fiber content. Am J Clin Nutr May 2008 vol. 87 no. 5 1298-1305
- http://www.hpb.gov.sg/HOPPortal/article?id=2652
- http://www.womenfirst.net/pdf/ADA/ADA_Iron.pdf
- http://www.irondisorders.org/Websites/idi/files/Content/854266/USDA_National_Nutrient_Database_-_iron.pdf
- http://www.iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrition/DRIs/1_%20EARs.pdf