Osteoporosis International

, Volume 23, Issue 1, pp 201–211

The effect of high-dose vitamin D on bone mineral density and bone turnover markers in postmenopausal women with low bone mass—a randomized controlled 1-year trial

  • G. Grimnes
  • R. Joakimsen
  • Y. Figenschau
  • P. A. Torjesen
  • B. Almås
  • R. Jorde
Original Article

DOI: 10.1007/s00198-011-1752-5

Cite this article as:
Grimnes, G., Joakimsen, R., Figenschau, Y. et al. Osteoporos Int (2012) 23: 201. doi:10.1007/s00198-011-1752-5

Abstract

Summary

Vitamin D is widely used in osteoporosis treatment, although the optimal dose is not known. This 1-year clinical study among 297 women aged 50–80 years old showed that a vitamin D3 dose of 6,500 IU/day was not better than the standard dose of 800 IU/day in improving bone mineral density (BMD) in the hip and spine.

Introduction

The purpose of this study was to determine whether a high dose of vitamin D3 was better than the standard dose in improving BMD and reducing bone turnover in postmenopausal women with reduced bone mass.

Methods

The study was a 1-year randomized double-blind controlled trial comparing high-dose vitamin D3 with the standard dose. Postmenopausal women (n = 297) with a BMD T-score ≤ −2.0 in either lumbar spine (L2–4) or total hip were included and randomized to 6,500 IU vitamin D3/day (20,000 IU twice per week + 800 IU/day) or 800 IU vitamin D3/day (placebo twice per week + 800 IU/day). Both groups were given 1,000 mg elemental calcium/day. The primary endpoint was a change in BMD in total hip and lumbar spine (L2–4).

Results

After 1 year, serum 25-hydroxyvitamin D (25(OH)D) increased [mean (SD)] from 71 (23) to 185 (34) nmol/l and from 71 (22) to 89 (17) nmol/l in the high- and standard-dose vitamin D groups, respectively. BMD at all measurement sites was unchanged or slightly improved with no significant differences between the groups. Although bone turnover was reduced in both groups, the more pronounced reduction in serum levels of the bone formation marker P1NP in the standard-dose group may indicate that this treatment was more efficient. Adverse events did not differ between the groups.

Conclusions

One year treatment with 6,500 IU vitamin D3/day was not better than 800 IU/day regarding BMD in vitamin D-replete postmenopausal women with reduced bone mass and was less efficient in reducing bone turnover.

Keywords

Bone mineral densityBone turnoverOsteoporosisPostmenopausal womenRandomized controlled trialVitamin D

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2011

Authors and Affiliations

  • G. Grimnes
    • 1
    • 2
  • R. Joakimsen
    • 1
    • 2
  • Y. Figenschau
    • 3
    • 4
  • P. A. Torjesen
    • 5
  • B. Almås
    • 6
  • R. Jorde
    • 1
    • 2
  1. 1.Tromsø Endocrine Research Group, Department of Clinical MedicineUniversity of TromsøTromsøNorway
  2. 2.Division of Internal MedicineUniversity Hospital of North NorwayTromsøNorway
  3. 3.Department of Medical BiologyUniversity of TromsøTromsøNorway
  4. 4.Department of Medical BiochemistryUniversity Hospital of North NorwayTromsøNorway
  5. 5.Hormone Laboratory, Department of EndocrinologyOslo University HospitalOsloNorway
  6. 6.Hormone LaboratoryHaukeland University HospitalBergenNorway