title: Safety of vitamin D replacement in patients with primary hyperparathyroidism and concomitant vitamin D deficiency.
abstract: OBJECTIVE
  To evaluate the safety of vitamin D replacement in patients with vitamin D deficiency and primary hyperparathyroidism.
  
  
  METHODS
  Retrospective chart review of 35 patients from our endocrine clinic, age 22 to 89 years, diagnosed with primary hyperparathyroidism and vitamin D deficiency, and treated with either 1,000 to 2,000 international units (IU) of vitamin D daily or 50,000 IU of vitamin D weekly for 5 months. Data were collected before and after treatment on serum calcium, 25-hydroxyvitamin D (25-OH D), intact parathyroid hormone (iPTH), phosphorus, alkaline phosphatase, nephrolithiasis, fractures, and osteoporosis.
  
  
  RESULTS
  25-OH D increased significantly, from a baseline of 14.65 ± 6.57 ng/mL to 42.17 ± 12.98 ng/mL after weekly treatment with 50,000 IU of vitamin D (P<.0001), and from 22.42 ± 5.47 ng/mL to 33.33 ± 6.39 ng/mL following daily treatment with 1,000 to 2,000 IU of vitamin D (P<.0001). Pre- and posttreatment unadjusted serum calcium remained stable in the high-dose group (10.80 ± 0.43 mg/dL vs. 10.72 ± 0.67 mg/dL; P = .47), but decreased slightly in the low-dose group (10.76 ± 0.58 mg/dL vs. 10.11 ± 0.54 mg/dL; P = .0007). After adjusting for age, sex, vitamin D, and PTH levels, the small calcium difference in the low-dose group became statistically insignificant. Treatment with either high or low doses of vitamin D did not significantly change iPTH levels. Creatinine remained stable in all patients, and no new cases of nephrolithiasis were reported.
  
  
  CONCLUSIONS
  Replacing vitamin D in mild primary hyperparathyroidism is safe, effective, and does not increase calcium to dangerous levels.
authors: Division of Endocrinology and Metabolism, University of Rochester Medical Center, Rochester, New York 14642, USA.
authors: Diana
authors: D
authors: Wagner
authors: Yinglin
authors: Y
authors: Xia
authors: Runhua
authors: R
authors: Hou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014807:Vitamin D / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D014807:Vitamin D; D002118:Calcium