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

What is the primary consequence of a severe deficiency in vitamin B6?

1. Sideroblastic anemia

2. Diabetes

3. Anemia

4. Cardiomyopathy

The correct answer is: Sideroblastic anemia

The primary consequence of a severe deficiency in vitamin B6 is sideroblastic anemia. Vitamin B6 (pyridoxine) plays a crucial role in the synthesis of hemoglobin and the production of red blood cells. It is essential in the process of integrating iron into hemoglobin, and when there is a deficiency of vitamin B6, the body cannot efficiently form hemoglobin. This leads to the accumulation of iron within the mitochondria of the erythroblasts, resulting in the characteristic ringed sideroblasts seen in sideroblastic anemia. Sideroblastic anemia specifically is characterized by the inability of the bone marrow to produce normal red blood cells despite adequate iron stores. Instead, the cells produced are often immature and dysfunctional. This condition can lead to symptoms of anemia, such as fatigue and weakness, but it is the specific mechanism linked to vitamin B6 deficiency that distinguishes it from other types of anemia. While other conditions listed may also be associated with vitamin deficiencies or other complex factors, they do not share the same direct link to vitamin B6 as sideroblastic anemia does. Thus, understanding the biochemical pathways and the roles of vitamins in erythropoiesis highlights why severe deficiency in vitamin B6 primarily results in siderobl