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 .
Calcitriol in the treatment of postmenopausal osteoporosis.
Calcitriol was compared with placebo in the treatment of postmenopausal osteoporosis in a double-blind , r and omized , parallel clinical trial of 24 months ' duration . Adjustment was made in dietary calcium to maximize the dose of calcitriol . The study was completed by 15 patients who received placebo and 12 patients who received calcitriol .  The calcitriol group had positive slopes ( compared with negative slopes for the placebo group ) for total body calcium , bone mineral content of the radius , bone mineral density of the lumbar spine , and radiographic absorptiometry of the middle phalanges . The difference between the two groups was statistically significant for each of these measurements . The fracture rate in the treatment group was 250 per 1,000 patient-years as compared with 333 for the placebo group . The mean dose of calcitriol was 0.8 micrograms per day . Hypercalcemia , hypercalciuria , and perhaps nephrolithiasis were observed as complications of treatment . Calcitriol increased bone mineral density by decreasing bone resorption , but not by increasing bone formation . Future studies should concentrate on treatment with oral calcitriol in lower doses . It would also be of interest to examine parenteral administration of calcitriol . It is possible that bone formation can be increased by achieving higher serum levels of the drug , whereas complications may be avoided by using a non-oral route of administration
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 .