iron (Fe) [i´ern]
a chemical element, atomic number 26, atomic weight 55.847. (See Appendix 6-1.) Iron is chiefly important to the human body because it is the main constituent of hemoglobin
, and other components of respiratory enzyme systems. A constant although small intake of iron in food is needed to replace erythrocytes
that are destroyed in the body processes. Most iron reaches the body in food, where it occurs naturally in the form of iron compounds. These are converted for use in the body by the action of the hydrochloric acid produced in the stomach. This acid separates the iron from the food and combines with it in a form that is readily assimilable by the body. Vitamin C enhances absorption of iron, and alkalis hamper absorption.
. The amount of new iron needed every day by the adult body is about 18 mg. A child needs more in proportion to weight. Although these amounts are very small, iron deficiencies may cause serious disorders. Three stages of iron deficiency are distinguished: iron depletion
or prelatent iron deficiency,
in which bodily stores are mildly depleted but no change in hematocrit or serum iron levels is detectable; latent iron deficiency,
in which the serum iron level has dropped but the hematocrit is unchanged and there is no anemia; and iron deficiency anemia
, a serious condition characterized by low to absent iron stores, low hematocrit, and other blood abnormalities. A great loss of blood, such as may result from bleeding ulcers, hemorrhoids, or injury, is the most common cause of a deficiency of iron. Women who lose much blood in menstruation may have to supplement their diet with iron-rich food. Iron deficiency sometimes occurs in pregnancy as a result of increased demands on the mother's blood. It may also occur in infants, since milk contains little iron. Although babies are born with an extra supply of hemoglobin, by the age of 2 or 3 months they need iron-rich food to supplement milk.
Iron preparations, such as ferrous sulfate, may be necessary in the treatment of iron deficiency anemia
; they should be administered after meals, never on an empty stomach. The patient should be warned that the drugs cause stools to turn dark green or black. Overdosage may cause severe systemic reactions.
An acute iron deficiency may warrant parenteral administration of an iron supplement. Hypersensitivity to iron supplements often occurs in patients with other known allergies. In other patients the parenteral administration of iron can cause vomiting, chills, fever, headache, joint pain, and urticaria.
Food Sources of Iron. Liver is the richest source of iron; 200 g (6 ounces) of liver contains a whole day's supply for an adult. Other iron-rich foods include lean meat, oysters, kidney beans, whole wheat bread, kale, spinach, egg yolk, turnip greens, beet greens, carrots, apricots, and raisins.
Iron metabolism. Uptake of heme iron or ferrous iron occurs in the intestine. From the intestine, iron is transported on transferrin to the liver or the bone marrow. Transferrin binds to red blood precursors in the bone marrow and delivers iron for incorporation into hemoglobin. Red blood cells in the circulation contain 60 percent to 80 percent of body iron. Old red blood cels are destroyed in the spleen. The iron is bound to transferrin for recirculation. Approximately 20 percent to 30 percent of iron is stored in the form of hemosiderin in the spleen, liver, and bone marrow. The remaining iron is in the respiratory enzymes of somatic cells. Iron is lost by desquamation of skin and intestinal cells. From Damjanov, 2000.
iron 59 a radioisotope of iron having a half-life of 44.5 days; used in ferrokinetics tests to determine the rate at which iron is cleared from the plasma and incorporated in red blood cells. Symbol 59Fe.
a complex of iron and dextran
of low molecular weight; administered intravenously or intramuscularly as a hematinic
iron poisoning poisoning from ingestion of excessive iron or iron-containing compounds, such as in children who eat iron supplement tablets like candy; symptoms include ulceration of the gastrointestinal tract, vomiting, vasodilation with shock, metabolic acidosis, liver injury, and coagulation disturbances.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
i·ron (Fe), (ī'ŏrn, ī'rŏn),
A metallic element, atomic no. 26, atomic wt. 55.847, which occurs in the heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins, and is an essential component of enzymes such as catalase, peroxidase, and the various cytochromes; its salts are used medicinally. For individual salts not listed below, see ferric and ferrous entries.
Farlex Partner Medical Dictionary © Farlex 2012
iron Iron-binding capacity, total iron-binding capacity, TIBC A metallic element–atomic number 26; atomic weight 55.8 essential to life, bound to Hb and responsible for O2 transportation–total iron refers to the amount of iron actually present in serum; iron and TIBC are performed on autoanalyzers Ref range Iron, 40-180 µg/dL; TIBC, 250-390 µg/dL. See Total iron-binding capacity, Transferrin.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
A metallic element, atomic no. 26, atomic wt. 55.847, which occurs in the heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins; an essential component of enzymes such as catalase, peroxidase, and the various cytochromes; salts used medicinally.
[M.E. iren, fr. O.E. īren]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
iron An element essential for the formation of HAEMOGLOBIN. Lack of iron, or excessive loss leads to IRON-DEFICIENCY ANAEMIA. Iron is provided in a variety of chemical forms for the treatment of anaemia and is usually taken by mouth. In urgent cases, or if oral therapy fails, iron can be given by injection.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
A metallic element that occurs in heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins and is an essential component of enzymes; its salts are used medicinally.
[M.E. iren, fr. O.E. īren]
Medical Dictionary for the Dental Professions © Farlex 2012
Patient discussion about iron
Q. Why do I need an iron supplement? I am a 22 year old woman and my doctor told me that I need an iron supplement. Why?
A. Here is a movie about iron deficiency:
Q. What is the recommended intake for iron? I had a blood test recently which detected I have iron deficiency. I wanted to know what is the recommended intake for iron and which foods are rich with iron?
A. Adult males need to consume about 8 mg of iron per day and females (not pregnant) need to consume about 18 mg of iron per day. There are two forms of dietary iron: heme and nonheme. Heme iron is derived from hemoglobin, the protein in red blood cells that delivers oxygen to cells. Heme iron is found in animal foods that originally contained hemoglobin, such as red meats, fish, and poultry. Iron in plant foods such as lentils and beans is arranged in a chemical structure called nonheme.
Q. Why do pregnant women need more iron? During my pregnancy my Doctor keeps on telling me I need to take an iron supplement. I eat healthy and eat meat, isn't that enough?
A. How much iron you need during pregnancy depends a lot on how much you already have stored in your bone marrow, as well as how much you get daily in your diet. If you are a meat eater, you will need less iron than a non meat eater however you will still need an iron supplement since during pregnancy you need to consume a great amount of iron that is impossible to consume from food alone. Consult with your Doctor and tell him to run you a blood test. If he sees you have enough iron he might not recommend an iron supplement and will be satisfied with only a Prenatal vitamin, which also contains iron but less. More discussions about iron
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