American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended treatment for patients with chronic kidney disease and normal calcium and phosphorus levels?

1. Active vitamin D analogues

2. Diuretics

3. Calcium supplements

4. Iron supplements

The correct answer is: Active vitamin D analogues

In patients with chronic kidney disease (CKD) who have normal calcium and phosphorus levels, the recommended treatment is the use of active vitamin D analogues. This is primarily due to the role of active vitamin D in regulating calcium and phosphate metabolism. As CKD progresses, patients often develop disturbances in mineral and bone metabolism, commonly referred to as chronic kidney disease-mineral and bone disorder (CKD-MBD). Even when calcium and phosphorus levels are normal, patients may have a deficiency in active vitamin D (calcitriol) because the kidneys can lose their ability to convert vitamin D to its active form. This can contribute to secondary hyperparathyroidism and result in adverse bone and mineral effects. Administering active vitamin D analogues can help maintain normal calcium and phosphorus levels while also suppressing parathyroid hormone secretion, promoting bone health, and improving overall mineral balance. This treatment is important for preventing complications associated with CKD-MBD, which can lead to cardiovascular issues and other systemic problems if left unaddressed. While diuretics, calcium supplements, and iron supplements play roles in various aspects of CKD management, they do not specifically target the underlying issues related to vitamin D deficiency in the context of CKD, especially when mineral