Two regimens , each represented by one large trial , which showed limited evidence of efficacy in reducing the incidence of hip or other appendicular skeleton fractures were : 1 ) Oral Vitamin D when accompanied by calcium supplementation .
2 ) 1,25 dihydroxy Vitamin D ( calcitriol ) .
This appeared more effective than calcium in a direct comparison .
Hypercalcaemia and gastro-intestinal symptoms , reported in less than 5 % of participants , were slightly more common when Vitamin D analogues were taken .
However , the risk of death was marginally less .
REVIEW ER 'S CONCLUSIONS Uncertainty remains about the efficacy of regimens which include Vitamin D or its analogues in fracture prevention .
Particularly if co-supplementation of calcium is required , significant cost differences are likely to exist between regimens .
BACKGROUND Due to their known effects on bone metabolism , Vitamin D and related compounds have been proposed for the prevention of osteoporosis and fractures .
OBJECTIVES To determine the effects of supplementation with Vitamin D or a Vitamin D analogue in the prevention of fractures of the axial and appendicular skeleton in elderly men or women with involutional or post-menopausal osteoporosis .
Low-dose calcitriol versus calcium in established postmenopausal osteoporosis.
An ongoing r and omized clinical trial of 3 years duration is being undertaken to evaluate the recurrent fracture rate and safety profile associated with low-dose calcitriol versus calcium supplementation in women with at least 3 years postmenopausal osteoporosis who are under the age of 80 years . A total of 856 patients were su bmi tted for possible inclusion in the study by 123 primary care physicians , and 636 met all entry requirements . Each patient was r and omly allocated to receive either 0.25 micrograms of calcitriol twice daily or calcium supplementation of 1,000 mg/d . If significant hypercalcemia developed ( greater than 2.6 mmol/L ) or a deterioration in renal function was observed , the dose of trial medication was to be halved or stopped if laboratory values did not return to normal . Patients were given no specific instructions regarding dietary calcium intake . To date , 528 patient-years experience with calcitriol  and 527 patient-years experience with calcium the calcium supplementation have been accumulated . Thus far , low-dose calcitriol has not been observed to cause hypercalcemia , deterioration in renal function , or nephrocalcinosis . At 1 year , a loss in total anterior height ( P less than .05 ) has been detected in the calcium-treated group compared with the calcitriol-treated group . Thus , calcitriol appears to preserve spinal height . Long-term follow-up of all patients for 2 or 3 years will be continued
Two regimens , each represented by one large trial , which showed limited evidence of efficacy in reducing the incidence of hip or other appendicular skeleton fractures were : 1 ) Oral Vitamin D when accompanied by calcium supplementation .
2 ) 1,25 dihydroxy Vitamin D ( calcitriol ) .
This appeared more effective than calcium in a direct comparison .
Hypercalcaemia and gastro-intestinal symptoms , reported in less than 5 % of participants , were slightly more common when Vitamin D analogues were taken .
However , the risk of death was marginally less .
REVIEW ER 'S CONCLUSIONS Uncertainty remains about the efficacy of regimens which include Vitamin D or its analogues in fracture prevention .
Particularly if co-supplementation of calcium is required , significant cost differences are likely to exist between regimens .
BACKGROUND Due to their known effects on bone metabolism , Vitamin D and related compounds have been proposed for the prevention of osteoporosis and fractures .
OBJECTIVES To determine the effects of supplementation with Vitamin D or a Vitamin D analogue in the prevention of fractures of the axial and appendicular skeleton in elderly men or women with involutional or post-menopausal osteoporosis .