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 .
Prevention of femoral and lumbar bone loss with hormone replacement therapy and vitamin D3 in early postmenopausal women: a population-based 5-year randomized trial.
The long term effects of hormone replacement therapy ( HRT ) and vitamin D3 ( Vit D ) on bone mineral density ( BMD ) were studied . A total of 464 nonosteoporotic early postmenopausal women from the Kuopio Osteoporosis Study ( n = 13100 ) were r and omized to four groups : 1 ) HRT ( sequential combination of 2 mg estradiol valerate and 1 mg cyproterone acetate , 2 ) Vit D3 ( 300 and 100 IU/day during the fifth year ) , 3 ) HRT and Vit D combined , and 4 ) placebo .  Lumbar ( L2-L4 ) and femoral neck BMD were determined by dual x-ray absorptiometry ( DXA ) at baseline and after 2.5 and 5 yr of treatment . Intention to treat analysis ( n = 464 ) showed that after 5 yr , lumbar BMD remained unchanged in the HRT and HRT plus Vit D groups [ + 0.2 % ( P = 0.658 ) and + 0.9 % ( P = 0.117 ) , respectively ] , whereas lumbar BMD decreased by 4.6 % in the Vit D group and by 4.5 % in the placebo group ( P < 0.001 in both ) . The loss of femoral neck BMD was less in the HRT ( -1.4 % ; P = 0.005 ) and HRT plus Vit D ( -1.3 % ; P = 0.003 ) groups than in the Vit D and placebo groups ( -4.3 % ; P < 0.001 in both ) . Among those 370 women who complied with the 5-yr treatment , the effect was more pronounced : lumbar BMD had increased by 1.5 % in the HRT ( P = 0.009 ) and by 1.8 % in the HRT plus Vit D group ( P = 0.005 ) , with a plateau after 2.5 yr , whereas lumbar BMD had decreased in both the Vit D and placebo groups ( 4.6 % and 4.7 % ; P < 0.001 , respectively ) . Femoral neck BMD decreased again less in the HRT ( -0.4 % ) and HRT plus Vit D ( -0.6 % ) groups than in the Vit D and placebo groups ( -4.4 % in both ) . This study confirms the positive long term effect of HRT on BMD also seen in intention to treat analysis . The data suggest that low dose vitamin D3 supplementation does not prevent  bone loss in healthy , nonosteoporotic , early postmenopausal women , and it confers no benefit additional to that of HRT alone
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 .