Hypercalcemia and acute kidney injury caused by occupational inhalation of vitamin D3: a case report.

Vitamin D intoxication is a rare but potentially life-threatening condition that can lead to severe hypercalcemia and serious complications. Most reported cases are associated with long-term or high-dose oral vitamin D preparations, dietary supplement use, or inappropriate iatrogenic prescribing. In contrast, occupational inhalation exposure remains exceedingly uncommon. We report the case of a 25-year-old man who developed parathyroid hormone (PTH)-independent hypercalcemia and acute kidney injury (AKI) due to excessive exogenous vitamin D3 exposure in the workplace. Following prompt treatment, his clinical condition improved and he was discharged. This case underscores the importance of actively eliciting a history of occupational exposure in patients with PTH-independent hypercalcemia, particularly when there is no clear history of oral supplement use, to reduce missed diagnoses and facilitate prompt recognition and treatment.