***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Observational studies examining the role of estrogen in the risk of kidney stone formation have shown conflicting results . However , r and omized trial evidence on nephrolithiasis risk with  estrogen therapy in postmenopausal women is lacking . METHODS We review ed the incidence of nephrolithiasis in the Women 's Health Initiative estrogen-alone and estrogen plus progestin trials conducted at 40 US clinical centers . A total of 10 739 postmenopausal women with hysterectomy were r and omized to receive 0.625 mg/d of conjugated equine estrogens ( CEE ) or placebo , and 16 608 postmenopausal women without hysterectomy were r and omized to receive placebo or estrogen plus progestin given as CEE plus medroxyprogesterone acetate ( 2.5 mg/d ) . The incidence of nephrolithiasis was determined for an average follow-up of 7.1 years for the CEE trial and 5.6 years for the estrogen plus progestin trial . RESULTS Baseline demographic characteristics and risk factors for nephrolithiasis were similar in the placebo and treatment arms . Estrogen therapy was associated with a significant increase in nephrolithiasis risk from 34 to 39 cases per 10 000 person-years ( hazard ratio , 1.21 ; 95 % confidence interval , 1.03 - 1.44 ) . Censoring data from women when they ceased to adhere to study medication increased the hazard ratio to 1.39 ( 95 % confidence interval , 1.08 - 1.78 ) . The increased nephrolithiasis risk was independent of progestin coadministration , and effects did not vary significantly according to prer and omization history of nephrolithiasis . CONCLUSIONS These data suggest that estrogen therapy increases the risk of nephrolithiasis  in healthy postmenopausal women . These findings should be considered in decision making regarding postmenopausal estrogen use . The mechanisms underlying this higher susceptibility remain to be determined . Trial Registration clinical trials.gov Identifier : NCT0000611 Although calcium supplements are widely used to reduce bone resorption in osteoporosis , their beneficial effect is not conclusively established . We studied the effect of a calcium supplement ( 1 g/day for 8 days ) in 14 postmenopausal osteoporotic women . The fasting urinary hydroxyproline/creatinine ratio decreased from 0.022 + /- 0.001 to 0.017 + /- 0.001 ( p less than 0.005 ) indicating a significant reduction in bone resorption . Both the tubular maximum for phosphate reabsorption ( 1.12 + /- 0.06 to 1.34 + /- 0.07 , p less than 0.005 ) and plasma phosphate concentration ( 1.04 + /- 0.04 to 1.14 + /- 0.04 , p less than 0.01 ) increased , consistent with suppression of parathyroid hormone activity . These results support the concept that calcium supplementation is useful in the treatment of postmenopausal osteoporosis We aim ed to compare and evaluate the efficacies of a continuous regimen of intranasal salmon calcitonin ( SCT ) and two cyclic regimens ( different cyclic regimens from previous studies ) based on alternating 15 days or on 10 days consecutively per month for 1 year in the treatment of postmenopausal osteoporosis . We performed an open-label , prospect i ve , r and omized clinical trial . A total of 120 postmenopausal osteoporotic participants between 50 and 65 years old were r and omly assigned to one of three treatment groups . Patients in group 1 ( n=40 ) received continuously SCT nasal spray at a dose of 200 IU/day , plus continuously 500 mg/day elementary calcium and 0.25 μg/day 1-α hydroxyvitamin D3 , for 1 year . Patients in group 2 ( n=40 ) received cyclically SCT nasal spray at a dose of 200 IU/day on alternating 15 days per month , plus continuously 500 mg/day elementary calcium and 0.25 μg/day 1-α hydroxyvitamin D3 , for 1 year . Patients in group 3 ( n=40 ) received cyclically SCT nasal spray on 10 days consecutively per month ( 20 days/month rest ) , plus continuously 500 mg/day elementary calcium and 0.25 μg/day 1-α hydroxyvitamin D3 , for 1 year . Data was evaluated by repeated analysis of variance ( ANOVA ) . In addition , statistical differences between groups were assessed by the two-tailed Student ’s t test . After 1 year of the study , seven patients from group 1 , eight patients from group 2 and five patients from group 3 withdrew from the study . No patient discontinued the study because of adverse drug effects . There was a statistically-significant improvement in pain intensity VAS scores at the end of the year to baseline scores in all three groups ( p<0.001 ) . There was no significant difference in pain intensity VAS scores between groups at the end of the year ( p>0.05 ) . Lumbar and femur neck BMD scores improved significantly at the end of treatment in all three groups ( p<0.05 ) . There was no statistically-significant difference in BMD scores between groups at final ( p>0.05 ) . Urinary DPD/Cre levels decreased significantly in all three groups by the end of the year ( p<0.05 ) . There was no statistically-significant difference in urinary DPD/Cre final levels between groups ( p>0.05 ) . According to the results of the present study , consecutive 10 days therapy with SCT , which is the first in the literature to our knowledge , is as effective as the other two regimens in the treatmnent of osteoporosis . Both cyclic regimens in our study ( alternating 15 days and 10 consecutive days each month for 1 year ) do appear to offer some advantages , especially economically and clinical ly , as compared to continuous treatment BACKGROUND AND OBJECTIVE Osteoporosis is emerging as a leading cause of substantial morbidity in India , particularly in postmenopausal women .  Teriparatide ( recombinant human parathyroid hormone [ 1 - 34 ] ) increases bone formation and improves bone microarchitecture , thereby reducing the risk of fractures . This study was conducted to evaluate the efficacy of teriparatide in increasing bone mineral density ( BMD ) in postmenopausal women with osteoporosis . MATERIAL AND METHODS A r and omised , prospect i ve , multicentre , open-label , controlled study was conducted on 82 postmenopausal women with established osteoporosis . Patients were r and omly divided into control and teriparatide groups , each group consisting of 41 patients . All the patients were supplemented with 1000 mg of elemental calcium and 500 IU of vitamin D throughout the study period of 180 days . Besides , teriparatide group patients were administered teriparatide 20 microg daily subcutaneously . Lumbar spine , femoral neck and total hip BMD , bone mineral content ( BMC ) and bone area were measured by dual energy x-ray absorptiometry ( DXA ) at baseline and at the end of 6 months of treatment . Bone biomarkers , such as serum bone specific alkaline phosphatase ( BSAP ) and serum osteocalcin ( OC ) , representing bone formation , and urinary deoxypyridinoline ( DPD ) , representing bone resorption were assessed at baseline , and at 3 and 6 months of treatment . RESULTS During the study period , 9 patients ( 11 % ) were lost to follow-up--6 in control group ( 7.3 % ) and 3 in teriparatide group ( 3.7 % ) . There was an excellent compliance to both oral and injectable medication . The investigational product teriparatide was well tolerated and there were no serious adverse events . In addition , there were no significant differences between the groups in the incidence of adverse events . The percentage of increase in lumbar spine BMD , which is the primary endpoint , was significantly ( P < 0.001 ) higher in teriparatide group compared to that in control group ( 6.58 % vs. 1.06 % ) . Further , teriparatide significantly increased percentage of change in lumbar spine T-score ( P < 0.001 ) , BMC ( P < 0.001 ) and bone area ( P < 0.028 ) compared to control group at 6 months . Administration of teriparatide result ed in a significant percentage of increase in all the bone biomarkers in teriparatide group compared to control group patients at 3 and 6 months over baseline , thereby showing that there was a significant increase in bone turnover in teriparatide group of patients . CONCLUSION These results show that teriparatide is an effective and safe drug in increasing the BMD and therefore , teriparatide provides yet another new therapeutic option for reducing the risk management of osteoporosis  in postmenopausal women ( clinical trials.gov number , NCT00500409 ) An ongoing r and omized clinical trial of 3 years duration is being undertaken to evaluate the recurrent fracture rate and safety profile associated with low-dose calcitriol versus calcium supplementation in women with at least 3 years postmenopausal osteoporosis who are under the age of 80 years . A total of 856 patients were su bmi tted for possible inclusion in the study by 123 primary care physicians , and 636 met all entry requirements . Each patient was r and omly allocated to receive either 0.25 micrograms of calcitriol twice daily or calcium supplementation of 1,000 mg/d . If significant hypercalcemia developed ( greater than 2.6 mmol/L ) or a deterioration in renal function was observed , the dose of trial medication was to be halved or stopped if laboratory values did not return to normal . Patients were given no specific instructions regarding dietary calcium intake . To date , 528 patient-years experience with calcitriol  and 527 patient-years experience with calcium the calcium supplementation have been accumulated . Thus far , low-dose calcitriol has not been observed to cause hypercalcemia , deterioration in renal function , or nephrocalcinosis . At 1 year , a loss in total anterior height ( P less than .05 ) has been detected in the calcium-treated group compared with the calcitriol-treated group . Thus , calcitriol appears to preserve spinal height . Long-term follow-up of all patients for 2 or 3 years will be continued To determine the clinical recommended dosage regimen of risedronate for the treatment of involutional osteoporosis in Japanese patients , dose-response relationships for the efficacy and safety of this drug were investigated using a multi-center , r and omized , double-blind , parallel group comparative design with four dose levels of risedronate ( placebo , 1 mg , 2.5 mg and 5 mg per day ) . A total of 211 patients diagnosed with involutional osteoporosis according to the criteria proposed by the Japanese Society for Bone and Mineral Research were r and omized and received one of the four doses once daily for 36 weeks . All patients were supplemented with 200 mg of calcium daily in the form of calcium lactate . The primary efficacy endpoint was the percent change in bone mineral density of the lumbar spine ( L2–L4 BMD ) determined by dual-energy X-ray absorptiometry ( DXA ) from baseline to the time of final evaluation . Changes in biochemical markers of bone turnover and safety profile were also compared . Percent changes in L2–L4 BMD at final evaluation in the placebo , and 1- , 2.5- , and 5-mg risedronate groups were 0.79±5.30 , 2.71±4.93 , 5.29±3.96 , and 5.15±4.25 % ( mean±SD ) , respectively . A linear dose-response relationship was obtained up to a dose of 2.5 mg , whereas no further increase in BMD was observed at 5 mg . The decrease in bone turnover markers , including N-terminal osteocalcin , phosphorus , and urinary deoxypyridinoline , also showed a linear dose-response relationship up to a dose of 2.5 mg . Alkaline phosphatase level decreased linearly up to a dose of 5 mg . Risedronate was well tolerated in this 36-week study with 1- to 5-mg doses . Neither the overall incidence of adverse events nor the percentage of patients without problem in overall safety assessment differed significantly among the dose groups including the placebo group . Based on these results , a once-daily dose of 2.5 mg of risedronate , which is half that used in Caucasians , is recommended for the treatment of involutional osteoporosis in Japanese patients BACKGROUND Strontium ranelate , a new oral drug shown to reduce vertebral fracture risk in postmenopausal women with osteoporosis , was studied in the Treatment of Peripheral Osteoporosis ( TROPOS ) study to assess its efficacy and safety in preventing nonvertebral fractures also . METHODS Strontium ranelate ( 2 g/d ) or placebo were r and omly allocated to 509 
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CONCLUSIONS According to our results , calcium supplements in the treatment of osteoporosis alone or in combination with another type of treatment does not significantly increase the risk of nephrolithiasis or renal colic