Sollip Kim1, Laura D Stephens2, Robert L Fitzgerald3. 1. Department of Laboratory Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea. 2. Department of Pathology, UC San Diego Health, San Diego, CA, United States. 3. Department of Pathology, UC San Diego Health, San Diego, CA, United States. Electronic address: rfitzgerald@ucsd.edu.
Abstract
BACKGROUND: In this report, we describe 2 contrasting cases of hypervitaminosis D. CASE PRESENTATION: Patient 1 was a 75-y old man who developed symptomatic hypercalcemia (peak serum calcium concentration of 15.3mg/dl; reference range: 8.5-10.6mg/dl), cardiac injury, and a high total serum vitamin D concentration of 243ng/ml (30-80ng/ml) as a result of daily consumption of prescribed 50,000IU ergocalciferol (vitamin D2) and 500mg calcium-citrate for 1y. Patient 2 was a 60-y old woman who consumed 40,000IU of cholecalciferol (vitamin D3) daily for >10months with a peak total serum vitamin D concentration of 479ng/ml (30-80ng/ml), but did not present with symptoms related to vitamin D toxicity. CONCLUSION: These cases demonstrate that individual responses to supraphysiologic concentrations of vitamin D for extended periods of time vary widely, and that defining a toxic concentration of this vitamin is difficult. The different outcomes in these two patients, despite months of high-dose vitamin D therapy, demonstrates that individual patient pharmacodynamics determine clinical sequelae.
BACKGROUND: In this report, we describe 2 contrasting cases of hypervitaminosis D. CASE PRESENTATION:Patient 1 was a 75-y old man who developed symptomatic hypercalcemia (peak serum calcium concentration of 15.3mg/dl; reference range: 8.5-10.6mg/dl), cardiac injury, and a high total serum vitamin D concentration of 243ng/ml (30-80ng/ml) as a result of daily consumption of prescribed 50,000IU ergocalciferol (vitamin D2) and 500mg calcium-citrate for 1y. Patient 2 was a 60-y old woman who consumed 40,000IU of cholecalciferol (vitamin D3) daily for >10months with a peak total serum vitamin D concentration of 479ng/ml (30-80ng/ml), but did not present with symptoms related to vitamin Dtoxicity. CONCLUSION: These cases demonstrate that individual responses to supraphysiologic concentrations of vitamin D for extended periods of time vary widely, and that defining a toxic concentration of this vitamin is difficult. The different outcomes in these two patients, despite months of high-dose vitamin D therapy, demonstrates that individual patient pharmacodynamics determine clinical sequelae.
Authors: Sara De Vincentis; Antonino Russo; Marta Milazzo; Amedeo Lonardo; Maria C De Santis; Vincenzo Rochira; Manuela Simoni; Bruno Madeo Journal: Endocr Metab Immune Disord Drug Targets Date: 2021 Impact factor: 2.895