title: Vitamin D status and response to daily 400 IU vitamin D3 and weekly alendronate 70 mg in men and women with osteoporosis.
abstract: BACKGROUND
  Suboptimal vitamin D status is common in elderly individuals. However, the extent of vitamin D inadequacy in men and women being treated for osteoporosis in a family practice setting has not been well characterized.
  
  
  OBJECTIVE
  To describe the distribution of serum 25-hydroxyvitamin D (25-[OH] D) in Canadian men and postmenopausal women with osteoporosis taking 400 IU or less of vitamin D daily and to evaluate the safety, tolerability, and impact of vitamin D(3) supplementation 400 IU daily taken concurrently with alendronate sodium 70 mg weekly.
  
  
  METHODS
  This was a prospective, single-cohort, open-label, multicenter study. Community-dwelling men and postmenopausal women with osteoporosis were recruited at 197 sites across Canada. Patients received vitamin D(3) 400 IU/day supplementation coadministered with alendronate 70 mg/wk for 16 weeks. The primary outcome was the distribution of serum 25-(OH) D at baseline. Secondary outcome measures included changes from baseline in serum 25-(OH) D levels, adherence to study treatments, and incidence of treatment-related adverse events (AEs).
  
  
  RESULTS
  Of the 681 patients included in the analysis, 485 (71.2%) completed the study. Patients were predominantly female (83.1%) with a mean (SD) age of 67.6 (10.7) years. At baseline, mean (SD) serum 25-(OH) D concentration was 25.4 (9.9) ng/mL and 68.0% of the patients had inadequate (less than 30 ng/mL) vitamin D status. At week 16, concentrations increased by 35.1% to 31.2 (9.2) ng/mL (p < 0.001) and the proportion of patients with inadequate 25-(OH) D levels was reduced to 47.0%. Adherence to the treatment regimen was high (greater than 95%). Gastrointestinal disorders were the most frequently reported (6.9%) treatment-related AEs.
  
  
  CONCLUSIONS
  About two thirds of patients previously diagnosed with osteoporosis have inadequate vitamin D status. A treatment regimen consisting of alendronate 70 mg/wk administered with daily vitamin D(3) 400 IU supplementation significantly increased patients' serum 25-(OH) D levels, but 47% did not achieve optimal levels. These results support both the National Osteoporosis Foundation and Osteoporosis Canada recommendations for higher vitamin D supplement doses (at least 800 IU daily) in osteoporotic patients receiving pharmacologic therapy for osteoporosis and for monitoring their serum 25-(OH) D response.
authors.affiliation: Division of Endocrinology, Department of Medicine, McGill University, Montreal, Quebec, Canada.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Karaplis
authors.forename: Fridon
authors.initials: F
authors.lastname: Chouha
authors.forename: Michel
authors.initials: M
authors.lastname: Djandji
authors.forename: John S
authors.initials: JS
authors.lastname: Sampalis
authors.forename: David A
authors.initials: DA
authors.lastname: Hanley
mesh_terms: D000368:Aged; D019386:Alendronate / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D002170:Canada; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000009:adverse effects; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000188:drug therapy*; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D011446:Prospective Studies; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D050071:Bone Density Conservation Agents; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D; D019386:Alendronate