Protection of Bone Density in Sarcoidosis: Can we Give Vitamin D without Causing Hypercalcemia?

Abstract

Objective: Sarcoidosis is commonly complicated by hypercalcemia due to extrarenal 1,25-dihydroxyvitamin D and parathyroid hormone–related peptide production. Bisphosphonates are often given to these patients to protect bone during steroid treatment; this is frequently preceded by vitamin D supplementation, both to prevent hypocalcemia and maximize bone mineralization. However, in sarcoidosis, vitamin D supplementation may augment the risk of hypercalcemia. We present a patient with steroid-treated sarcoidosis in whom high-dose vitamin D supplementation resulted in symptomatic hypercalcemia. Review of the literature provides insights regarding vitamin D supplementation for these patients and may be used to inform future guidelines and management. Methods: Case report and literature review. Results: An 82-year-old man with steroid-treated sarcoidosis and osteopenia presented with classic symptoms of hypercalcemia after high-dose vitamin D supplementation. The hypercalcemia responded to hydration, withholding of vitamin D, and high-dose steroid treatment. Most studies evaluating vitamin D supplementation in sarcoid patients reveal increases in calcium and 1,25-dihydroxyvitamin D levels with high-dose vitamin D supplementation, with some patients developing frank hypercalcemia. In contrast, a single large study using low-dose vitamin D supplementation found no increased hypercalcemia risk and revealed evidence of disease modulation. Conclusion: High-dose vitamin D supplementation in sarcoid patients is complicated by increased levels of calcium and 1,25-dihydroxyvitamin D, with an associated increased risk of hypercalcemia. In contrast, supplementation with low-dose vitamin D does not appear to increase risk of hypercalcemia and may have a positive effect on sarcoid disease activity. Abbreviation: PTHrP parathyroid hormone–related peptide