title: Management of hypovitaminosis D in patients with primary hyperparathyroidism.
abstract: OBJECTIVE
  Epidemiological studies suggest that vitamin D deficiency is common in patients with primary hyperparathyroidism (PHPT). They have higher levels of serum parathyroid hormone (PTH) and markers of bone turnover and fractures are more frequent than vitamin D-replete patients. However, there are concerns that Vitamin D repletion might exacerbate pre-existent hypercalcaemia. Therefore, we aimed to determine if vitamin D replacement improved biochemical indices of calcium metabolism without worsening underlying hypercalcaemia.
  
  
  METHODS
  This is a prospective, observational study based on routine clinical practice, set up in a secondary care centre. 45 consecutive patients with mild biochemical hypercalcaemia due to PHPT and hypovitaminosis D were enrolled. The mean age of the cohort was 61 years (range 25-85 years), predominately Asian (32 patients) and female (41 patients). They received 20,000 IU of oral cholecalciferol, once a week, for 3 months. Calcium, phosphate, alkaline phosphatase and PTH were measured at baseline, 4, 8 and 12 weeks following treatment. Vitamin D levels were obtained at baseline and at 12 weeks, after they completed their treatment.
  
  
  RESULTS
  Vitamin D levels normalised at week 12 (mean ± SD, 18.8 ± 9.4 versus 76 ± 20 nmol/L, p = 0.0001) and PTH levels improved following treatment completion (21.2 ± 10 versus 16.2 ± 6 pmol/L, p = 0.026). There was no significant increase in serum calcium levels during vitamin D supplementation.
  
  
  CONCLUSIONS
  High doses of oral cholecalciferol normalised vitamin D levels without worsening underlying hypercalcaemia in individuals with PHPT.
authors: Department of Diabetes and Endocrinology, Bradford Teaching Hospitals NHS Foundation Trust, Duckworth Lane, Bradford, BD9 6RJ, UK, manjusharathi@doctors.org.uk.
authors: M S
authors: MS
authors: Rathi
authors: S
authors: S
authors: Gonzalez
authors: D
authors: D
authors: Wright
authors: N R
authors: NR
authors: Ellis
authors: S R
authors: SR
authors: Peacey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002112:Calcifediol / Q000097:blood; D002118:Calcium / Q000097:blood; D002762:Cholecalciferol / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000139:chemically induced / Q000209:etiology; D049950:Hyperparathyroidism, Primary / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D063728:Secondary Care Centers; D012720:Severity of Illness Index; D006113:United Kingdom; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000178:diet therapy*
chemical_list: D015415:Biomarkers; C470125:PTH protein, human; D010281:Parathyroid Hormone; D002762:Cholecalciferol; D002112:Calcifediol; D002118:Calcium