Endocrine Abstracts

Introduction

Current standard treatment of primary hypoparathyroidism is based on calcium and activated vitamin D supplementation. Iatrogenic severe hypercalcemia due to vitamin D intoxication is an uncommon complication rarely described in literature. Herein we report 5 cases of severe hypercalcemia secondary to vitamin D intoxication.

Observations

Three men and two women with chronic hypoparathyroidism were included in this study. Their mean age was 56 years with extremes of 18 and 76 years. All patients were admitted in our department for a severe hypercalcemia secondary to vitamin D intoxication. Calcium bicarbonate was prescribed at the dose of 1500 mg per day in all of them. One patient was overdosed in active vitamin D, while the other patients presented dosing error in this drug. Four patients had abdominal pain and asthenia. However, one patient had confusion and agitation. The five patients had dehydration signs with acute renal failure. Electrical changes of hypercalcemia were present in three of them. The mean calcium level was 156 mg/l with extremes of 130 and 182 mg/l. Hemodialysis was indicated in one patient who had neurological symptoms. His calcium level decreased from 182 mg/l to 134 mg/l. All of patients received normal saline rehydration with a duration of 2–3 days and an infusion of 3 l/24 h. The mean of calcemia declined from 147 mg/l to 113 mg/l and reached normal levels in three patients after rehydration. Intravenous corticosteroids were prescribed in two patients and helped to normalize calcium level. Bisphosphonates were not prescribed in any patient.

Conclusion

Iatrogenic hypercalcemia due to vitamin D intoxication can present a life-threatening condition indicating urgent and appropriate management. Intravenous saline rehydration, intravenous corticosteroids and eventually hemodialysis should be considered in this situation. Furthermore, education of patients with chronic hypoparathyroidism on their doses of vitamin D as well as symptoms of hypercalcemia is the cornerstone of severe hypercalcemia prevention.