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 postmenopausal bone loss by low and conventional doses of calcitriol or conjugated equine estrogen.
OBJECTIVES Estrogen deficiency is the most common cause of postmenopausal osteoporosis and estrogen replacement is well known to retard postmenopausal bone loss . Calcium supplement alone is generally considered to be insufficient for the prevention of bone loss associated with estrogen deficiency while the role of calcitriol is unclear . In the present study we examined the efficacy different doses of estrogen or calcitriol in the prevention of  postmenopausal bone loss in Thais . METHODS The subjects consisted of 146 Thai women no more than 6 years postmenopausal . The subjects were r and omly allocated to receive 750 mg supplemental calcium alone , calcium and conjugated equine estrogen ( CEE ) at 0.3 or 0.625 mg , calcium and calcitriol at 0.25 or 0.5 microg daily . Those receiving CEE also took 5 mg medrogestone for 12 days each month . BMD at L2 - 4 and femoral neck were measured at baseline 1 year and 2 years after treatments . Data were expressed as mean + /- S.E. RESULTS Subjects on supplemental calcium alone had approximately 2.5 % decreases in L2 - 4 ( P < 0.05 ) and femoral BMD ( P < 0.01 ) at 2 years . CEE ( 0.3 mg ) result ed in 3.20 + /- 1.2 % increase in vertebral BMD ( P < 0.05 ) while no significant change in BMD was demonstrated at the femoral neck . Likewise , 0.625 mg of CEE induced 5.4 + /- 1.4 % increase in vertebral BMD at 2 years ( P < 0.001 ) without change in the femoral BMD . In regard to calcitriol , no significant change in vertebral or femoral BMD was demonstrated with either 0.25 or 0.5 microg calcitriol . CONCLUSION We concluded that calcitriol is effective in the prevention of early postmenopausal bone loss in Thais . It represents an option for the prevention of osteoporosis in postmenopausal women who are contraindicated for estrogen replacement
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 .