National Board of Chiropractic Examiners (NBCE) Practice Test

What is the most likely cause of microcytic anemia?

1. Vitamin B12 deficiency

2. Folate deficiency

3. Iron deficiency

4. Lead poisoning

The correct answer is: Iron deficiency

Microcytic anemia is primarily characterized by the presence of smaller-than-normal red blood cells and is most commonly associated with iron deficiency. This occurs because iron is crucial for the production of hemoglobin, the protein in red blood cells responsible for oxygen transport. When the body lacks sufficient iron, hemoglobin synthesis is impaired, leading to the production of microcytic red blood cells. Iron deficiency can result from various factors, including inadequate dietary intake, chronic blood loss (such as through menstruation or gastrointestinal bleeding), or malabsorption issues. In contrast, vitamin B12 and folate deficiencies typically lead to macrocytic anemia, characterized by larger than normal red blood cells, while lead poisoning can cause a mixed picture but is more commonly linked with basophilic stippling in red blood cells. Thus, recognizing the specific characteristics of microcytic anemia and its links to iron metabolism is crucial in understanding why iron deficiency stands out as the most likely cause.