The Dark Side of the Sunshine Vitamin: A Case of Acute Renal Failure and Hypercalcaemia From Vitamin D Overconsumption

Vitamin D toxicity is a rare but potentially serious condition that can lead to severe hypercalcaemia and subsequent complications, such as acute renal failure, nephrocalcinosis, congestive heart failure and coronary calcium deposition, resulting in myocardial injury. We present a case of a 76-year-old male patient who developed severe hypercalcaemia and acute kidney injury due to excessive long-term over-the-counter vitamin D supplementation. The patient was initially treated with aggressive intravenous fluids and furosemide. However, a failed effective response prompted the addition of pamidronate, resulting in the gradual improvement of hypercalcaemia and renal function. We have presented, in this case, a rare adverse effect of vitamin D toxicity and its multiorgan effect.