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 .
Administration of a supplement containing both calcium and vitamin D is more effective than calcium alone to reduce secondary hyperparathyroidism in postmenopausal women with low 25(OH)vitamin D circulating levels
Background and aims : Supplementation of postmenopausal women with calcium alone or calcium-vitamin D association  was suggested to have positive effects on bone turnover and bone density , as well as to lower fracture incidence . The beneficial effect appears to be mediated by a reduction in parathyroid hormone secretion . Our aim was to compare the respective efficacy of calcium and calcium-vitamin D supplements in reducing serum parathyroid hormone levels in postmenopausal women with prevalent low 25(OH)vitamin D levels . Methods : One hundred consecutive ambulatory postmenopausal women with serum 25(OH)vitamin D levels below 18 ng/mL were included in a r and omized , prospect i ve , open label study . For a duration of 90 days , the women were r and omly assigned to a daily supplementation of either one tablet of calcium gluconolactate and carbonate ( 500 mg calcium ) , or one powder-pack of an association of calcium carbonate ( 500 mg calcium ) , citric acid ( 2.175 gr ) and cholecalciferol ( 200 IU ) . Changes observed during the 90 days of the study in circulating PTH levels were the primary endpoint , while changes in serum 25(OH)D levels were assessed as secondary endpoint . Results : A significant difference was observed between the calcium-vitamin D ( CaD ) and the calcium ( Ca ) only groups for changes occurring during the 90 days of the study in PTH ( −14.5±40 % and + 2.5±46 % ) ( p=0.009 ) and 25(OH)D ( + 67±77 % and + 18±55 % ) ( p<0.001 ) circulating levels . PTH changes between baseline and day 90 were significant in the CaD group , but not in the Ca group . The odds ratio for a patient in group Ca to experience an absolute ( < 12 ng/mL ) deficiency in circulating 25(OH)vitamin D levels , compared to a group CaD patient was statistically increased ( OR : 3.22 , 95 % CI : 1.33–7.80 ) . Conclusions : Our results support the recommendation of supplementing postmenopausal women with low circulating levels of 25(OH)vitamin D with a combination of calcium and vitamin D , rather than with calcium 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 .