Treatment of Vitamin D Excess (Hypervitaminosis D)
The primary treatment for vitamin D excess (hypervitaminosis D) is immediate discontinuation of all vitamin D supplements, ensuring adequate hydration, and following a low-calcium diet until calcium and vitamin D levels normalize. 1, 2
Immediate Management
- Discontinue all forms of vitamin D supplementation, including multivitamins containing vitamin D 1, 2
- Provide intravenous hydration to promote calcium excretion and protect renal function 3
- Implement a low-calcium diet until serum calcium levels normalize 1, 3
- Monitor serum calcium, phosphorus, and renal function regularly 4
Pharmacological Interventions (for severe cases)
- For severe hypercalcemia, consider calcitonin administration to rapidly lower serum calcium levels 3
- Bisphosphonates (e.g., pamidronate) may be used in cases of persistent hypercalcemia to inhibit bone resorption 3
- Loop diuretics may be considered to enhance calcium excretion, but only after adequate hydration is established 1
Monitoring and Follow-up
- Check serum calcium and phosphorus levels at least every 3 months during recovery 4
- Monitor 25-hydroxyvitamin D levels until they return to the normal range (30-80 ng/mL) 4, 5
- Assess renal function regularly, as hypercalcemia can cause acute kidney injury 6, 2
Expected Recovery Timeline
- Serum calcium levels typically normalize within 1-2 weeks after discontinuation of vitamin D 2
- Renal function usually recovers within 4-6 months 2
- 25-hydroxyvitamin D levels may take 12-18 months to return to normal range due to vitamin D's storage in adipose tissue 2
Prevention of Recurrence
- Once levels normalize, if vitamin D supplementation is indicated, use appropriate dosing (typically 800-2000 IU daily) 4, 5
- Avoid high-dose vitamin D regimens (>4,000 IU daily) without medical supervision 5, 7
- Be cautious with nutritional supplements that may contain undeclared vitamin D 3
Common Pitfalls to Avoid
- Failure to recognize dispensing errors as a cause of vitamin D toxicity 6
- Overlooking nutritional supplements as potential sources of excessive vitamin D 3
- Continuing calcium supplements during treatment of hypervitaminosis D 1
- Using intermittent high-dose vitamin D regimens, which carry higher risk of toxicity 4, 7
Special Considerations
- Vitamin D toxicity typically occurs with daily intakes exceeding 100,000 IU or when serum 25(OH)D levels exceed 100 ng/mL 5
- Recovery may be prolonged due to vitamin D's fat-soluble nature and long half-life 2
- Patients with chronic kidney disease require special attention as they may have altered vitamin D metabolism 4