Safety of Vitamin D Replacement in Patients with Primary Hyperparathyroidism and Concomitant Vitamin D Deficiency.
Endocr Pract. 2013 Jan 21:1-20.
Wagner D, Xia Y, Hou R.
Division of Endocrinology and Metabolism, University of Rochester Medical Center, Rochester, New York.
Objective: To evaluate the safety of vitamin D replacement in patients with vitamin D deficiency and primary hyperparathyroidism.
Methods: Retrospective chart review on 35 patients from our Endocrine clinic, age 22-89, diagnosed with primary hyperparathyroidism and vitamin D deficiency and treated with either 1000-2000 IU of vitamin D daily or 50,000 IU of Vitamin D weekly for 5 months. Data were collected on serum calcium, 25-OH vitamin D, iPTH, PO4, alkaline phosphatase, nephrolithiasis, fractures and osteoporosis before and after treatment.
Results: The 25-OH vitamin D level increased significantly from a baseline of 14.65±6.57 ng/ml to 42.17±12.98 ng/ml after treatment with 50,000 IU of vitamin D weekly (P<0.0001). It also increased significantly from 22.42±5.47 ng/ml to 33.33±6.39 ng/ml in patients treated with 1000-2000 IU of vitamin D daily (P<0.0001). The pre and post treatment unadjusted serum calcium level remained stable in the high dose group (10.80±0.43 mg/dl vs 10.72±0.67 mg/dl, p=0.47) but decreased mildly in the low dose group (10.76±0.58 mg/dl vs. 10.11±0.54 mg/dl, p=0.0007). After adjustment for age, sex, vitamin D and PTH levels this mild calcium difference in the low dose group became statistically insignificant. Treatment with either high or low dose of vitamin D did not change intact PTH levels significantly. Creatinine remained stable in all patients and no new case of nephrolithiasis was reported.
Conclusion: Replacing vitamin D in mild primary hyperparathyroidism is safe, effective and does not increase calcium to dangerous levels.