Microcytic anemia is a type of iron deficiency, and the term "microcytic" means "small cells" and refers to the appearance of iron-deficient red blood cells. These cells cannot deliver oxygen to target tissues as efficiently as normal cells. Many conditions may cause iron deficiency, including some form of blood loss, inadequate dietary intake, a blood production disorder or destruction of blood cells within the circulatory system. Proper treatment varies depending on the underlying cause or causes.
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Addressing Blood Loss
According to the Merck Manual, iron deficiency is the most common cause of anemia and usually results from chronic blood loss. In premenopausal women, frequent or heavy menstrual periods are often the culprit. In these cases, hormone therapy can correct the problem; however, excessive uterine bleeding from other causes such as fibroids may make surgery a better option. In men, gastrointestinal (GI) bleeding is the most frequent source of iron depletion. GI bleeding may be from ulcers, inflammatory bowel conditions or even severe hemorrhoids. Prolonged use of aspirin or other anti-inflammatory drugs may also cause GI bleeding. Identification of the precise source of the blood loss will determine the best course of treatment.
Since iron absorption is hindered by dietary fiber, dairy products and soy protein—and since meat is one of the best sources iron—vegetarians are generally considered to be at increased risk for developing anemia. Lentils, dried beans, grain products, vegetables, dried fruit and molasses are non-meat sources of iron in the diet. Iron absorption may be enhanced by consuming iron-rich food along with citrus fruits, berries, melons or tomatoes. Calcium-rich dairy foods, which interfere with iron absorption, should be consumed separately if the goal is to increase absorption of iron in a meal. An article published in the American Journal of Clinical Nutrition in 2000 provides an in-depth discussion of these dietary factors that influence iron absorption.
The Centers for Disease Control and Prevention guidelines call for a therapeutic dose of 60 milligrams (mg) of elemental iron once or twice per day for the anemic person. Since certain nutrients like calcium can interfere with iron absorption, it is best to avoid taking iron supplements along with most other supplements. An exception is vitamin C, in the form of ascorbic acid, which enhances iron absorption. Taking 500 mg of ascorbic acid along with the iron may be beneficial. Note: Too much iron at one time can be toxic; consult your doctor to determine appropriate levels for you. This supplement should be stored where young children or pets do not have access.
The National Institutes of Health Office of Dietary Supplements describes three types of athletes that may be at risk for developing iron-deficiency anemia: vegetarians, females and distance runners. The vegetarian athlete risks depleting iron stores due to inadequate dietary intake of iron. The female athlete is vulnerable due to menstrual loss of blood and the high metabolic demands of training. Long-distance running exposes the capillaries of the feet to repetitive micro-trauma leading to breakdown of red blood cells. The body's stores of iron are tapped for the production of new blood cells. Reducing mileage or cross-training will reduce this type of blood cell turnover.
Microcytic anemia that persists or reoccurs despite seemingly appropriate treatment might suggest a less common underlying cause. Monitoring the status of the anemia with follow-up laboratory analysis of the blood helps to guard against a missed diagnosis and also helps ensure that treatment measures are not prematurely abandoned based on resolution of symptoms alone.