Iron deficiency

From WikiMD's Wellness Encyclopedia

Iron deficiency is a common global nutritional problem primarily caused by poor iron intake, malabsorption, or chronic blood loss. It is a state that can progress to Iron deficiency anemia if not properly managed. Iron plays a crucial role in a number of essential physiological processes, and its deficiency can lead to a myriad of health issues.

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Koilonychia iron deficiency anemia

Introduction[edit | edit source]

Iron deficiency is characterized by the body's inability to maintain sufficient levels of iron to meet its physiological needs. It is considered the most widespread nutritional disorder in the world, affecting both developing and developed countries. While it is often associated with anemia, iron deficiency can exist without causing anemia. This stage of the condition is often referred to as Non-anemic iron deficiency.[1]

Physiology of Iron[edit | edit source]

  • Iron is an essential element for all living organisms. In humans, it is a critical component of hemoglobin, a protein in red blood cells that carries oxygen from the lungs to the tissues. It is also a part of myoglobin, a protein that helps supply oxygen to the muscles, and many enzymes that drive chemical reactions in the body.[2]
  • The regulation of iron in the body involves a complex balance between absorption, transport, storage, and loss of iron. Iron is absorbed in the duodenum and the jejunum in the small intestine. From there, it enters the bloodstream where it is transported throughout the body by transferrin, a plasma protein. When not in use, iron is stored as ferritin or hemosiderin in the liver, spleen, and bone marrow.[3]

Causes of Iron Deficiency[edit | edit source]

  • The most common causes of iron deficiency include insufficient dietary intake, poor absorption, and blood loss. In developing countries, a diet low in iron-rich foods like meat and leafy greens can lead to iron deficiency. In developed countries, iron deficiency is often associated with conditions that lead to malabsorption, such as Celiac disease, Crohn's disease, and Gastric bypass surgery.[4]
  • Chronic blood loss, from conditions such as heavy menstrual bleeding, peptic ulcer disease, or certain types of cancer can also cause iron deficiency. Iron deficiency can occur in pregnancy due to the increased iron needs of the growing fetus and placenta.[5]

Symptoms and Complications[edit | edit source]

  • Iron deficiency can lead to a variety of symptoms, ranging from fatigue and weakness to cognitive impairment. Other common symptoms include pica (a craving for non-nutritious substances), restless legs syndrome, and pagophagia (a specific form of pica involving the consumption of ice).
  • Untreated iron deficiency can progress to iron deficiency anemia, a more severe condition characterized by a decrease in the number of red blood cells and a corresponding decrease in their oxygen-carrying capacity. This can lead to shortness of breath, rapid heart rate, and decreased physical and cognitive performance.[6]

Diagnosis[edit | edit source]

Diagnosing iron deficiency involves a combination of clinical evaluation and laboratory testing. The physician typically reviews the patient's medical history and symptoms, and may conduct a physical examination. Laboratory tests commonly include a complete blood count (CBC), serum ferritin, transferrin saturation, and serum iron. These tests can help determine the body's iron stores and the presence of anemia.[7]

Treatment[edit | edit source]

  • The treatment of iron deficiency primarily involves increasing iron intake through diet and supplementation. Iron-rich foods, such as lean meats, leafy greens, and fortified cereals, can help boost iron levels. Oral iron supplements are often recommended, but intravenous iron may be required in cases of severe iron deficiency, malabsorption, or intolerance to oral iron.
  • Treatment should also address the underlying cause of iron deficiency, such as treating conditions causing blood loss or malabsorption. Follow-up blood tests are usually conducted to monitor the patient's response to treatment and ensure iron stores are replenished.[8]

Prevention[edit | edit source]

Preventing iron deficiency involves a balanced diet rich in iron, routine screening in populations at risk, and addressing the causes of iron loss. In developing countries, strategies like iron fortification of foods and deworming programs can help prevent iron deficiency.[9]

Epidemiology[edit | edit source]

Iron deficiency is the most common nutritional disorder in the world, affecting an estimated 2 billion people. It is especially prevalent in women of childbearing age, pregnant women, infants, and children. Iron deficiency anemia affects an estimated 30-40% of pregnant women and 40-50% of children aged 6-24 months in developing countries.[10]

See Also[edit | edit source]

References[edit | edit source]

  1. World Health Organization, "Worldwide prevalence of anaemia 1993–2005", WHO Global Database on Anaemia.
  2. Andrews, Nancy C., "Disorders of Iron Metabolism", New England Journal of Medicine, 1999, 341:1986-1995.
  3. Muckenthaler, Martina U., et al. "Systemic Iron Homeostasis and the Iron-Responsive Element/Iron-Regulatory Protein (IRE/IRP) Regulatory Network", Annual Review of Nutrition, 2008, 28:197-213.
  4. Hershko, C., et al. "Iron, Folic Acid, and Vitamin B12", Best Practice & Research Clinical Haematology, 2005, 18:281-294.
  5. Breymann, C., "Iron Deficiency Anemia in Pregnancy", Seminars in Hematology, 2015, 52:339-347.
  6. Camaschella, Clara, "Iron Deficiency Anemia", New England Journal of Medicine, 2015, 372:1832-1843.
  7. Brittenham, Gary M., "Iron Deficiency and Overload", Hematology (Am Soc Hematol Educ Program), 2010, 2010:40-47.
  8. Auerbach, Michael, et al. "American Society of Hematology 2020 guidelines for management of iron deficiency anemia", Blood Advances, 2020, 4:5373-5415.
  9. Zimmermann, Michael B., and Hurrell, Richard F. "Nutritional Iron Deficiency", Lancet, 2007, 370:511-520.
  10. Stevens, Gretchen A., et al. "Global, Regional, and National Trends in Haemoglobin Concentration and Prevalence of Total and Severe Anaemia in Children and Pregnant and Non-Pregnant Women for 1995–2011: A Systematic Analysis of Population-Representative Data", The Lancet Global Health, 2013, 1:e16-e25.
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