What is iron?
Iron is a chemical element with the symbol Fe (from Latin: ferrum) and atomic number 26. It is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth’s outer and inner core. It is the fourth most common element in the Earth’s crust. Its abundance in rocky planets like Earth is due to its abundant production by fusion in high-mass stars, where it is the last element to be produced with release of energy before collapse into a compact object. Like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are by far the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, water and air. Fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, exposing fresh surfaces for corrosion.
Iron forms binary compounds with the halogens and the chalcogens. Among its organometallic compounds is ferrocene, the first sandwich compound discovered.
Iron is an essential nutrient that plays a key role in many physiological processes. Some of the health benefits associated with iron include:
1. Helps transport oxygen throughout the body: Iron is a key component of hemoglobin, a protein found in red blood cells that helps transport oxygen from the lungs to other tissues in the body. Without adequate iron, the body cannot produce enough hemoglobin, leading to iron deficiency anemia.
2. Boosts cognitive development and memory: Iron is also involved in brain development and cognitive function. Low iron levels have been linked to impaired cognitive development in infants and children, as well as problems with memory and attention span in adults.
3. Supports a healthy immune system: Iron is necessary for the production of immune cells. Without enough iron, the body cannot produce the necessary amount of white blood cells, which help fight infection.
4. Prevents fatigue: Because iron is essential for oxygen transport, a lack of iron can lead to feelings of fatigue and weakness. Iron supplementation has been shown to improve energy levels in people with iron deficiency anemia.
5. Promotes healthy pregnancy: Iron is essential for the development of the fetus and placenta during pregnancy. It also helps prevent birth defects and low birth weight. Pregnant women who are iron deficient are at risk for premature labor and delivery.
Iron deficiency is the most common nutritional deficiency in the world, affecting over two billion people. The best way to ensure adequate iron intake is to eat a varied diet that includes iron-rich foods, such as red meat, poultry, fish, beans, lentils, spinach, and iron-fortified cereals and breads. Some people, particularly those with chronic blood loss or certain gastrointestinal disorders, may require iron supplementation.
While iron is essential for good health, too much iron can be toxic. Symptoms of iron toxicity include stomach pain, nausea, vomiting, diarrhea, constipation, headache, dizziness, and fatigue. Iron overload can lead to more serious problems including liver damage, heart problems, and diabetes. People with hemochromatosis (a hereditary condition that causes the body to absorb too much iron) are at especially high risk for iron toxicity. Treatment for iron toxicity includes removing the source of excess iron (such as supplements or fortified foods) and chelation therapy, which involves taking medication to remove excess iron from the body.
The recommended daily allowance (RDA) for iron is 8 mg for men and 18 mg for women. Pregnant women should aim for 27 mg of iron per day. The upper limit for iron intake is 45 mg per day for adults. Children and teenagers should not exceed 40 mg per day.
Iron can interact with certain medications and supplements. For example, iron may decrease the absorption of non-heme iron (found in plant foods), so it’s best to take iron supplements on an empty stomach. Iron can also interact with antacids, calcium, and some antibiotics. Be sure to speak with a healthcare professional before taking iron supplements to ensure they are right for you.
Iron is absorbed in the small intestine and stored in the liver, spleen, and bone marrow. It is excreted in the feces.