Claudia Battista1, Raffaella Viti1, Salvatore Minisola2, Iacopo Chiodini3, Vincenzo Frusciante4, Alfredo Scillitani1, Vincenzo Carnevale5. 1. Unit of Endocrinology, "Casa Sollievo della Sofferenza" Hospital, IRCCS, San Giovanni Rotondo (FG), Italy. 2. Department of Clinical Sciences, University of Roma "Sapienza", Italy. 3. Unit of Endocrinology, Department of Medical Sciences, Fondazione Policlinico IRCCS, University of Milan, Italy. 4. Unit of Nuclear Medicine, "Casa Sollievo della Sofferenza" Hospital, IRCCS, San Giovanni Rotondo (FG), Italy. 5. Unit of Internal Medicine, "Casa Sollievo della Sofferenza" Hospital, IRCCS, San Giovanni Rotondo (FG), Italy.
Abstract
OBJECTIVE: To describe the biochemical effects of an over-supplementation of vitamin D3 in two patients with primary hyperparathyroidism (PHPT). DESIGN: Two patients (A and B) with PHPT took erroneously 2,400,000 U (300,000 U/day for 8 days) and 4,500,000 U (300,000 U/day for 15 days) of cholecalciferol, respectively. They were followed for 4 months and ionized calcium, creatinine, PTH, 25 hydroxy-vitamin D, 1,25(OH)₂D and urinary calcium/creatinine levels were measured. Finally, the patients were operated on and a parathyroid adenoma was removed in both. RESULTS: One week after the last dose of vitamin D, serum ionized calcium (iCa) rose from 1.35 to 1.41 mMol/L (n.r. 1.14-1.31) for patient A, and from 1.43 to 1.62 for patient B, while fasting urinary Calcium/Creatinine (uCa/Cr) augmented from 0.31 to 0.50 mg/mg, and from 0.32 to 0.55, respectively. During the follow-up, the average levels of iCa were 1.37 ± 0.03 and 1.48 ± 0.07 mMol/L, while those of uCa/Cr were 0.29 ± 0.13 and 0.32 ± 0.13, both iCa and uCa/Cr levels returning to baseline values within 4 months. CONCLUSIONS: The unintentional over-supplementation of vitamin D in the two PHPT patients caused a moderate and temporary increase of hypercalcemia and hypercalciuria and was not associated with clinical signs of toxicity.
OBJECTIVE: To describe the biochemical effects of an over-supplementation of vitamin D3 in two patients with primary hyperparathyroidism (PHPT). DESIGN: Two patients (A and B) with PHPT took erroneously 2,400,000 U (300,000 U/day for 8 days) and 4,500,000 U (300,000 U/day for 15 days) of cholecalciferol, respectively. They were followed for 4 months and ionizedcalcium, creatinine, PTH, 25 hydroxy-vitamin D, 1,25(OH)₂D and urinary calcium/creatinine levels were measured. Finally, the patients were operated on and a parathyroid adenoma was removed in both. RESULTS: One week after the last dose of vitamin D, serum ionizedcalcium (iCa) rose from 1.35 to 1.41 mMol/L (n.r. 1.14-1.31) for patient A, and from 1.43 to 1.62 for patient B, while fasting urinary Calcium/Creatinine (uCa/Cr) augmented from 0.31 to 0.50 mg/mg, and from 0.32 to 0.55, respectively. During the follow-up, the average levels of iCa were 1.37 ± 0.03 and 1.48 ± 0.07 mMol/L, while those of uCa/Cr were 0.29 ± 0.13 and 0.32 ± 0.13, both iCa and uCa/Cr levels returning to baseline values within 4 months. CONCLUSIONS: The unintentional over-supplementation of vitamin D in the two PHPT patients caused a moderate and temporary increase of hypercalcemia and hypercalciuria and was not associated with clinical signs of toxicity.