Secondary hyperparathyroidism may result from:A.decreased synthesis of active vitamin D and increased intestinal calcium absorption.B.increased synthesis of active vitamin D and increased intestinal calcium absorption.C.decreased synthesis of active vitamin D and decreased intestinal calcium absorption.D.increased synthesis of active vitamin D and decreased intestinal calcium absorption

Secondary hyperparathyroidism may result from:

C. decreased synthesis of active vitamin D and decreased intestinal calcium absorption.

Here's why:

Secondary hyperparathyroidism is a disorder of the parathyroid glands in which they secrete too much parathyroid hormone (PTH). This condition is often a response to low calcium levels in the blood, which can be caused by various factors.

One of these factors is the decreased synthesis of active vitamin D. Vitamin D is essential for the absorption of calcium in the intestines. When there is a decrease in the synthesis of active vitamin D, less calcium is absorbed from the diet, leading to lower calcium levels in the blood.

The parathyroid glands respond to this low calcium level by secreting more PTH to try to increase the calcium level. This is why decreased synthesis of active vitamin D can lead to secondary hyperparathyroidism.

Similarly, if there is decreased intestinal calcium absorption for any reason, this can also lead to lower calcium levels in the blood, triggering the parathyroid glands to secrete more PTH. This is why decreased intestinal calcium absorption can also lead to secondary hyperparathyroidism.