Which vitamin excess is associated with hypercalcemia and renal calculi?

Vitamin D is essential for calcium absorption and homeostasis in the body. When there is an excess of vitamin D, it leads to increased absorption of calcium from the gastrointestinal tract, resulting in hypercalcemia. This condition occurs because elevated levels of calcium can cause the bones to release more calcium into the bloodstream, as well as promoting calcium reabsorption from the kidneys.

The clinical manifestations of vitamin D excess include hypercalcemia, which may lead to symptoms such as nausea, vomiting, weakness, and confusion. In addition to hypercalcemia, high levels of calcium can precipitate in the kidneys, forming renal calculi, also known as kidney stones. The excessive calcium levels surpass the solubility limits in the urine, facilitating the crystallization process that leads to stone formation.

Other vitamins listed, such as vitamin E, vitamin K, and folate, do not have the same effects on calcium metabolism and are not known to cause hypercalcemia or kidney stones. Their roles in the body are different and do not involve significant interactions with calcium homeostasis.