Iron is an important component of hemoglobin, the protein molecules in red blood cells that carry oxygen for distribution within the body. Unfortunately, certain circumstances can impair the ability of bone marrow to produce red blood cells, resulting in a condition known as anemia. In addition, Iron deficiency can make red blood cells less efficient at carrying oxygen.
Anemia
Anemia is defined by an abnormally low number of red blood cells circulating in the bloodstream. There are many different types of anemia, each with their own individual causes and characteristics. One method of further categorizing anemia is by the size of the available red blood cells. Macrocytic anemia occurs when red blood cells are larger than normal size. This often occurs as a result of vitamin B12 and folate deficiency which can delay DNA synthesis and red blood cell division. As a result of the delay, red blood cells are given time to grow larger. In contrast, microcytic anemia occurs with red blood cells that are smaller than normal.
Iron Deficiency Anemia
Anemia that occurs in iron deficiency is usually of the microcytic variety. Without sufficient availability of iron, red blood cells may contain less hemoglobin resulting in smaller-sized cells. Risk factors of iron deficiency anemia include prolonged bleeding, heavy menstruation, malabsorption syndromes, and poor dietary iron intake. Symptoms of anemia can include weakness, pale skin, fatigue and drowsiness.
Hypothyroidism and Anemia
Hypothyroidism is often complicated by anemia. Low thyroid hormone levels can affect multiple organs including the kidneys. A primary function of the kidney is to produce a hormone called erythropoietin, which stimulates the production of red blood cells in bone marrow. Iron deficiency can exacerbate anemia that results from hypothyroidism. Although microcytic anemias can occur, hypothyroidism is more commonly associated with macrocytic anemia resulting from impaired vitamin B12 absorption.
Lab Tests for Iron Deficiency Anemia and Hypothyroidism
In order to identify iron deficiency anemia and hypothyroidism, various lab tests may have to be run from a sample of the patient’s blood. Important labs in detecting iron deficiency include total iron binding capacity and body iron stores. Complete blood cell count and red blood cell indices help to identify the presence and type of anemia. Hypothyroidism labs include the measurement of the thyroid hormones T3 and T4. In addition thyroid stimulating hormone is usually increased in patients with hypothyroidism.
Iron Therapy
Iron therapy may be useful in patients who suffer from hypothyroidism and are at risk for iron deficiency. Treatment includes the use of oral iron supplements, or in severe cases, the use of intravenous iron. Patients should contact a physician if they have concerns regarding hypothyroidism, iron deficiency or anemia.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
References:
1. GI Health: “Iron Deficiency Anemia” (Accessed December 3, 2010).
2. MayoClinic.com: “Hypothyroidism” (Accessed December 3, 2010).
3. National Anemia Action Council: “Effective Iron Replacement Therapy for Subclinical Hypothyroid Patients” (Accessed December 3, 2010).
4. National Heart Lung and Blood Institute: “Iron-Deficiency Anemia” (Accessed December 3, 2010).
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