Iron is an essential element for the human body since it plays a pivotal role in several life processes. Iron indeed participates in the formation of the red blood cells, in addition to this, it is a component of many enzymes such as that responsible for energy production. This trace element should be introduced though diet but not all the ingested iron is then absorbed by the body. In fact, the percentage of iron absorbed by the small intestine ranges from 5 to 35% on the basis of the conditions and the type of iron. In human body there is indeed a feedback mechanism that modulates the absorption of iron by increasing or, on the contrary, decreasing it in case of iron deficiency or excess. As for the type of iron, the iron that comes from animal sources is more easily assimilable by body than that with a plant based origin. There are also other factors that contribute to increase, or decrease, iron assimilation, for example, vitamin C and citric acid facilitate the absorption of iron, for this reason the advice is to season vegetables and legumes with lemon juice or to eat at end of a meal a vitamin C rich fruit such as oranges or kiwi fruits. On the contrary, there are also other substances, such as phytates present in cereals and legumes and some phenols of coffee and tea that may counteract iron absorption (Abbaspour et al, J Res Med Sci, Feb 2014 - Johnson-Wimbley, Therap Adv Gastroenterol, May 2011 - Geissler et al, Nutrients, Mar 2011). A possible iron deficiency may be due to the type of diet, but may be also caused by bleedings, intestinal inflammatory problems or renal impairment, pregnancy, in this period in fact the need of iron increases. A lack of iron in the body may cause tiredness, a poor resistance to physical and mental fatigue, poor concentration, irritability and higher risk of developing infections. In case of demonstrated iron deficiency then taking supplements may be useful, a good choice, in order to avoid intolerances, is to take small amount of iron, 5 mg three times a day (Natural Medicine From A to Z, Bruno Brigo), but this should be done only after medical advice and in the riskier cases such as in small children, during pregnancy, breastfeeding, in women of childbearing age and elderly. In case of iron it is very important to ask always your doctor for advice because, although this mineral is essential to life, it produces also free radicals and an excess of iron may damage the tissues. For this reason, except cases in which the iron deficiency is well demonstrated, for the others a good choice is to take iron through diet by changing often the sources in order to get the optimal intake and to avoid in this way an iron excess. Let’s see the main sources of iron, both of animal and plant based origin, the data refers to 100 grams of product and come from USDA Food Composition Database.
Animal source
Liver (30 mg) and red meat, seafood such as clams (10 mg) and mussels (2 mg), fat fish, for example salmon (0,8 mg) and anchovies (2,4 mg).
Plant based source
Dry apricots (about 2,6 mg), leafy greens, for example lettuce (about 1,2mg), kale (1,6 mg) and spinach (2,71 mg), parsley (6,20 mg), legumes, for example lentils (6,5 mg) and cannellini beans (2 mg), tofu (1,7 mg), quinoa (1,49 mg), beet root (0,8 mg) and dark chocolate (17 mg).
