American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Which mineral deficiency is linked to the development of sideroblastic anemia?

1. Zinc

2. Copper

3. Vitamin B6

4. Chromium

The correct answer is: Vitamin B6

Sideroblastic anemia is characterized by the presence of sideroblasts in the bone marrow, which are red blood cell precursors that contain iron granules but fail to incorporate it effectively into hemoglobin. One of the crucial factors in the synthesis of heme, the iron-containing component of hemoglobin, is vitamin B6 (pyridoxine). This vitamin acts as a cofactor for the enzyme ALA synthase (aminolevulinate synthase), which is essential in the heme biosynthesis pathway. When there is a deficiency of vitamin B6, the production of heme is impaired, leading to ineffective erythropoiesis and the accumulation of iron in the form of sideroblasts. This biochemical pathway highlights vitamin B6's critical role in preventing sideroblastic anemia, establishing the link between its deficiency and the development of this type of anemia. In contrast, while minerals like zinc and copper are involved in various biochemical processes, and chromium's role relates more to glucose metabolism, they have not been directly implicated in the etiology of sideroblastic anemia. Thus, vitamin B6 deficiency is specifically recognized as a key factor in the disorder's pathophysiology.