Hypervitaminosis d, renal involvement

Hypervitaminosis D results from an excessive intake of vitamin D and causes nephrocalcinosis. Vitamin D is a dietary compound, whose primary role is mediation of the intestinal absorption of calcium. A secondary effect of hypervitaminosis D is the resorption of bone and release of calcium into the systemic circulation. These patients manifest the symptoms of hypercalcaemia, including hypercalciuria, nephrolithiasis and nephrocalcinosis. Renal failure develops eventually in patients with persistent hypervitaminosis D.

Imaging findings of hypervitaminosis D are those of hypercalcaemia and hypercalciuria. Hypercalciuria results in the formation of calcium oxalate and calcium phosphate stones, which are densely radiopaque on plain film radiography and CT. On ultrasound, a calcium stone is detected as an echogenic focus with posterior acoustic shadowing. While CT, ultrasound, and excretory urography can all be used to detect any associated collecting system obstruction, CT is the preferred imaging modality because of its sensitivity and accuracy in depicting extrarenal abnormalities. See hypercalcaemia renal involvement and hypercalciuria

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