Vitamin D overdose can cause kidney failure and require dialysis

Excessive vitamin D supplementation can lead to kidney failure and the need for dialysis due to hypercalcemia. Taking too much vitamin D, a fat-soluble vitamin, causes calcium levels to spike, overwhelming the kidneys' filtering capacity and potentially causing severe damage. Vitamin D toxicity is almost exclusively caused by supplements, not sun exposure or diet, and symptoms are often mistaken for common ailments.