A patient with secondary hyperparathyroidism questions the nurse regarding the need for adequate vitamin D intake. The nurse understands that vitamin D is necessary for the parathyroid hormone to exert its effects because
• Secondary hyperparathyroidism results from a homeostatic mechanism that seeks to compensate for low levels of serum calcium.
• Hypocalcemia signals the body to release parathyroid hormone (PTH), which increases renal calcium resorption as osteoclasts are triggered to begin digesting formed bone and to release calcium to compensate for the imbalance.
• For this reason, patients with secondary parathyroidism are prescribed Vitamin D to help increase dietary calcium absorption in the intestines instead.
• Vitamin D is converted into its active form in the kidney.
• Vitamin D is not used to synthesize parathyroid hormone.