Published in:
Open Access
01-05-2008 | Original Article
Efficacy of different doses and time intervals of oral vitamin D supplementation with or without calcium in elderly nursing home residents
Authors:
V. Chel, H. A. H. Wijnhoven, J. H. Smit, M. Ooms, P. Lips
Published in:
Osteoporosis International
|
Issue 5/2008
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Abstract
Summary
The effect of equivalent oral doses of vitamin D3 600 IU/day, 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a randomized clinical trial in nursing home residents. A daily dose was more effective than a weekly dose, and a monthly dose was the least effective.
Introduction
It is assumed that equivalent daily, weekly or monthly doses of vitamin D3 equally influence vitamin D status. This was investigated in a randomized clinical trial in nursing home residents.
Methods
The study was performed in ten nursing homes including 338 subjects (76 male and 262 female), with a mean age of 84 (± SD 6.3 years). They received oral vitamin D3 either 600 IU/day, or 4200 IU/week, or 18,000 IU/month or placebo. After 4 months, calcium was added during 2 weeks, 320 mg/day or 640 mg/day or placebo. Outcome: serum levels of 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH) and bone turnover markers. Statistical approach: linear multilevel analysis.
Results
At baseline, mean serum 25(OH)D was 25.0 nmol/L (SD 10.9), and in 98%, it was lower than 50 nmol/L. After 4 months, mean serum 25(OH)D levels increased to 62.5 nmol/L (after daily vitamin D3 69.9 nmol/L, weekly 67.2 nmol/L and monthly 53.1 nmol/L, P < 0.001 between groups). Median serum PTH levels decreased by 23% (p < 0.001). Bone turnover markers did not decrease. Calcium supplementation had no effect on serum PTH and bone turnover.
Conclusion
Daily vitamin D was more effective than weekly, and monthly administration was the least effective.