USMLE Step 2 Clinical Knowledge (CK) Practice Exam

Hypercalcemia due to hypervitaminosis D is associated with several complications, and one of the notable complications is the formation of kidney stones. This occurs because the elevated levels of calcium in the blood lead to increased calcium excretion in the urine, a condition known as hypercalciuria. When calcium levels in the urine are high, it can combine with oxalate or phosphate to form calcium-containing stones, such as calcium oxalate or calcium phosphate stones.

Additionally, hypervitaminosis D can also elevate phosphate levels, further contributing to the risk of kidney stone formation. The interplay between increased intestinal absorption of calcium (due to excess vitamin D) and the alteration of renal handling of calcium and phosphate amplifies this risk.

While hypercalcemia can lead to acute kidney injury through mechanisms like nephrocalcinosis or direct renal damage due to high calcium levels, the specific and direct complication linked to hypervitaminosis D driving kidney stone formation makes it the most relevant answer in this context.