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 .
Combined Calcium and Vitamin D3 Supplementation in Elderly Women: Confirmation of Reversal of Secondary Hyperparathyroidism and Hip Fracture Risk: The Decalyos II Study
Vitamin D insufficiency and low calcium intake contribute to increase parathyroid function and bone fragility in elderly people .  Calcium and vitamin D supplements can reverse secondary hyperparathyroidism thus preventing hip fractures , as proved by Decalyos I. Decalyos II is a 2-year , multicenter , r and omized , double-masked , placebo-controlled confirmatory study . The intention-to-treat population consisted of 583 ambulatory institutionalized women ( mean age 85.2 years , SD = 7.1 ) r and omized to the  calcium – vitamin D3  fixed combination group ( n= 199 ) ; the calcium plus vitamin D3 separate combination group ( n= 190 ) and the placebo group ( n= 194 ) . Fixed and separate combination groups received the same daily amount of calcium ( 1200 mg ) and vitamin D3 ( 800 IU ) , which had similar pharmacodynamic effects . Both types of calcium-vitamin D3 regimens increased serum 25-hydroxyvitamin D and decreased serum intact parathyroid hormone to a similar extent , with levels returning within the normal range after 6 months . In a subgroup of 114 patients  , femoral neck bone mineral density ( BMD ) decreased in the placebo group ( mean = –2.36 % per year , SD = 4.92 ) , while remaining unchanged in women treated with calcium-vitamin D3 ( mean = 0.29 % per year , SD = 8.63 ) . The difference between the two groups was 2.65 % ( 95 % CI = –0.44 , 5.75 % ) with a trend in favor of the active treatment group . No significant difference between groups was found for changes in distal radius BMD and quantitative ultrasonic parameters at the os calcis . The relative risk ( RR ) of HF in the placebo group compared with the active treatment group was 1.69 ( 95 % CI = 0.96 , 3.0 ) , which is similar to that found in Decalyos I ( RR = 1.7 ; 95 % CI = 1.0 , 2.8 ) . Thus , these data are in agreement with those of Decalyos I and indicate that calcium and vitamin D3 in combination reverse senile secondary hyperparathyroidism and reduce both hip bone loss and the risk of hip fracture  in elderly institutionalized women
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 .