Which of the following elements is NOT affected in CKD-MBD?

In the context of chronic kidney disease—mineral and bone disorder (CKD-MBD), sodium levels are typically not directly affected. CKD primarily influences the metabolism of calcium, vitamin D, and parathyroid hormone (PTH), leading to various complications associated with bone health and mineral metabolism.

Calcium levels can be disrupted due to impaired renal function, affecting the balance of calcium reabsorption and excretion. Vitamin D metabolism is significantly altered in CKD—because the kidneys play a crucial role in converting vitamin D into its active form, and this process becomes impaired as kidney function declines. PTH is also affected, as the gland often compensates for low calcium levels and dysfunctional vitamin D metabolism by producing more hormone, leading to secondary hyperparathyroidism.

Sodium, however, is generally regulated differently by the kidneys and may not exhibit the same direct disturbances that are characteristic of the mineral and hormone levels involved in CKD-MBD. Therefore, sodium is not considered affected in the same way as calcium, vitamin D, or parathyroid hormone in the context of this disorder.