Hypervitaminosis D refers to excess vitamin D ingestion. This most often occurs due to overingestion of vitamin D. Very few foods contain high levels of vitamin D, so excess ingestion typically results from overdosing on supplements. The recommended upper-limit daily dose for adults is 4000 international units (IU) daily, but the upper-limit dose is lower for infants and children. Patients with renal disease, osteoporosis, or inflammatory bowel disease may require significantly higher doses (10 000-50 000 IU daily). Patients requiring high levels for repletion should have surveillance levels checked.

The primary complication of excess vitamin D levels is hypercalcemia. In the acute setting, hypercalcemia can result in nausea, emesis, altered mental status, weakness, polyuria, and polydipsia. Chronic vitamin D toxicity can result in the precipitation of kidney stones as well as bone demineralization and subsequent bone pain. Hypervitaminosis D in children can result in brain injury.