What is iron (food)?
In organisms iron plays an important role. The protein hemoglobin owes its activity of iron ions and iron is also an important component of many enzymes.
This iron in food sources such as meat, fish, cereals, potatoes, legumes, beans and other vegetables.
The divalent iron rate Fe2 +, the so-called heme iron, is well absorbed by the body and is found in meat. The trivalent iron Fe3 +, the so-called non-heme iron, which is found in vegetables, must first be converted into the divalent iron before it can be absorbed by the body. This takes place in an acidic environment. Therefore, it is recommended to steel pills, which consist of the divalent ferrous fumarate, to be taken in, for example, orange juice with vitamin C or a tablet. Vitamin C prevents oxidation of divalent iron to the trivalent form. Milk and milk products interfere with the conversion to divalent iron, in that they make it less acidic gastric juice. In an iron deficiency can also organic iron compounds such as iron aminochelate be ingested, which have a better effect.
Required Daily Allowance
The daily amount of iron will depend on the age and sex. By menstruation women lose on average twice as much iron as men. Also during pregnancy is the need for iron greater. The Dutch Health Council is the recommended daily allowance (RDA) for men set between 22-50 years to 11 milligrams for adult women and 15 milligrams.
With a shortage of iron (for example, during pregnancy) can occur anemia, this is because there is not enough iron is available to keep the hemoglobin synthesis levels. Iron deficiency is, in addition to shortage by menstruation, however, usually a result of chronic blood loss from the gastro-intestinal system such as, for example, inflammations, gastric and duodenal ulcers, tumors (usually of the colon), and sometimes also hemorrhoids. Sometimes, an iron deficiency is a result of lack of iron in the diet. It may also be that iron is not well absorbed by the small intestine, for example, as a result of small intestine operations or inflammation, for example, by a gluten allergy (celiac disease). A fixed iron deficiency is always cause to find out the cause, apart from (some) iron deficiencies in women who are menstruating.
Toxicity and overdose
Too many to Fe2 + ions react with peroxides, which free radicals are created.
About 1 gram of iron in the blood gives a two year old child already severe poisoning and three grams can be fatal. In an adult male occurred at approximately 2.5 grams of iron in the blood poisoning on. Prolonged causes too much iron hemochromatosis, an iron storage disease, wherein the excess iron is stored in the liver. In secondary siderosis the iron is stored in the liver macrophages (Kupffer cells) of the liver. Also can cause damage to other organs. An excess of divalent iron can cause neurodegenerative diseases in the brains under special conditions, such as Parkinson's disease or Alzheimer's Disease.
Enzymes
In addition to the occurrence of iron into hemoglobin and myoglobin it also occurs in many enzymes in the form of iron-sulfur complexes (Iron-sulfur cluster-), for example in nitrogenasen and hydrogenases. Then there are the so-called non-heme iron enzymes, such as the methane monooxygenase, ribonucleotide reductase and hemerythrine. These proteins provide for different organisms to oxygen activation, oxygen transport, redox reactions and hydrolyses. Similarly, it is important the trivalent iron as the central ion in the enzyme catalase, which in the peroxisomes of the cells responsible for the degradation of the toxic for the cell is hydrogen peroxide. Hydrogen peroxide formed as a by-product of the metabolism of the cell.