human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective . To examine how cumulative teenage sports histories and time-averaged  teenage calcium intake are related to total body bone mineral gain  between ages 12 and 18 years and to proximal femur bone mineral density ( BMD ) at age 18 years . Design . Longitudinal . Setting . University Hospital and local suburban community in Central Pennsylvania . Study Participants . Eighty-one white females in the ongoing Penn State Young Women 's Health Study . Outcome Measures . Total body and proximal femur ( hip ) bone measurements by dual energy radiograph absorptiometry ; nutrient intakes  , including  calcium  , from 33 days of prospect i ve food records collected at regular intervals between ages 12 and 18 years ; and self-reported sports – exercise scores  between ages 12 and 18 years . Results . Cumulative sports – exercise scores between ages 12 and 18 years were associated with hip BMD at age 18 years ( r = .42 ) but were not related to total body bone mineral gain . Time-averaged daily  calcium  intake , which ranged from 500 to 1500 mg/day in this cohort was not associated with hip BMD at age 18 years , or with total body bone mineral gain at age 12 through 18 years . Conclusions . The amount of physical activity that distinguishes a primarily sedentary teenager from one who engages in some form of exercise on a nearly daily basis is related to a significant increase in peak hip BMD We have previously demonstrated a negative impact on peak bone mass in girls with precocious puberty treated with GnRH agonist ( GnRHa ) .  Several studies have shown that a high calcium intake positively influences bone mass in prepubertal girls and leads to a higher peak bone mass . The aim of this study was to evaluate the effect of calcium supplementation in girls with precocious puberty during GnRHa treatment .  Forty girls affected by true central precocious puberty and treated with the GnRHa triptorelin were studied for 2 yr . After diagnosis , the patients were r and omly assigned to three groups : group A , treated only with GnRHa ; group B , treated for 12 months solely with GnRHa and then supplemented with calcium gluconolactate/carbonate ( 1 g calcium/day in two doses ) for 12 months ; and group C , treated from the beginning with combined GnRHa and calcium .  Bone mineral density ( BMD ) at the lumbar spine was measured by dual energy x-ray absorptiometry at the beginning of the study and after 12 and 24 months and was expressed as the calculated true volumetric density ( BMDv ) in milligrams per cm3 . Group A showed a decrease in absolute BMDv levels , in SD score for chronological age ( CA ) , and even more in SD score for bone age ( BA ) . Group B showed the same behavior during the first year , but this trend was reversed in the second year , when calcium supplementation was added to GnRHa treatment . Group C showed an increase in absolute BMDv levels and in SD score for CA and BA . BMDv variations ( expressed as absolute values , SD score for CA , and SD score for BA ) became statistically significant at 24 months between groups C and A ( P = 0.036 , P = 0.032 , and P = 0.025 , respectively ) . The behavior of the lumbar spine BMDv in the three groups is consistent with a positive effect of calcium supplementation during GnRHa treatment . In calcium-supplemented patients , the normal process of bone mass accretion at puberty is preserved despite GnRHa treatment . Therefore , the reduction in BMD during GnRHa treatment in girls with precocious puberty is at least completely reversible and preventable if calcium supplementation is associated from the beginning Carbonated beverages have been reported to increase fracture risk in children but the mechanism is unclear . The aim of this population -based case-control study was to investigate the association between soft drink and milk consumption , physical activity , bone mass , and upper limb fractures in children aged 9–16 years . A total of 206 fracture cases and 206 r and omly selected individually matched controls were studied . There were 47 h and fractures ; 128 wrist and forearm fractures , and 31 upper arm fractures . An interviewer-administered question naire was utilized to retrospectively assess last-year physical activity ( including television , computer , and video watching ) and to recall the average weekly consumption of milk , colas , and total carbonated drinks .  Bone mass at the spine , hip , and total body was assessed by dual-energy X-ray absorptiometry ( DXA ) and metacarpal morphometry . For total fractures , none of the above drink types was significantly different between cases and controls . For wrist and forearm fractures , there was a positive association between cola drink consumption and fracture risk ( OR 1.39/unit , 95 % CI : 1.01 , 1.91 ) . Cola consumption was significantly correlated with television , computer , and video watching ( r = 0.20 , P = 0.001 ) but not bone mineral density or milk drinks . After adjustment for television , computer , and video watching and bone mineral density , the association between cola drinks and fracture risk became nonsignificant ( OR 1.31/unit , 95 % CI : 0.94 , 1.83 ) . No association with other fracture sites was observed . In conclusion , cola , but not total carbonated beverage consumption , is associated with  increased wrist and forearm fracture risk in children . However , this association is not independent of other factors and appears to be mediated by television watching and bone mineral density but not by decreased milk intake Over the past 20 years , orally administered biphosphonates have been used extensively in the management of a number of common skeletal disorders of different etiology . Recently , in clinical practice , in a number of cases in whom oral therapy is insufficient or contraindicated , intravenous administration of pamidronate presents an alternative therapeutic option . In order to investigate the clinical and radiological effects of cyclic intravenous pamidronate administration in children with osteogenesis imperfecta , a prospect i ve open study of pamidronate treatment was undertaken in a cohort of eight bed-bounded ( 3.6 - 13.8 years ) patients with severe osteoporosis and vertebral deformities .  Pamidronate was administered at a dose of 0.5 mg/kg/ day for three days . Tri-monthly cyclic intravenous infusions were performed over-one year . Bone density , verebral corpus heights , estimated volumetric bone density and biochemical measurements were analyzed . Side effects of the therapy were determined via question naire . Significant reductions in the number of bone fractures and pain were observed in all patients . Ambulation scores were significantly altered and seven of eight patients became independent . Serum alkaline phosphatase levels decreased significantly . Lumbar X-ray and densitometry showed a striking improvement by the end of the treatment period . Even spaced dense lines corresponding to infusion periods were observed on roentgenograms of the radio-ulnar region . Pubertal progression and growth velocity were not affected inversely during therapy . Although we did not observe any severe side effect , one patient 's blood urea nitrogen level was altered slightly . In conclusion , one year cyclical pamidronate treatment seems to be effective and safe in improving bone mineralization and in reducing fracture incidence in severe osteoporosis BACKGROUND There is no agreement on how much calcium young girls need for optimal bone mineralization . OBJECTIVE We evaluated whether the effect of calcium supplementation on whole-body bone mineral accretion depends on habitual calcium intake . DESIGN This was a r and omized , double-blind , placebo-controlled , 1-y calcium intervention study of girls aged 12 - 14 y selected from a larger group according to habitual calcium intake : subgroup A ( n = 60 ) habitually consumed 1000 - 1307 mg/d ( 40th-60th percentile ) , and subgroup B ( n = 53 ) habitually consumed < 713 mg/d ( < 20th percentile ) . The girls from each subgroup were r and omly assigned to receive either 500 mg Ca/d or placebo .  Whole-body bone mineral content ( BMC ) , bone area ( BA ) , bone mineral density ( BMD ) , and BMC adjusted for BA , height , and weight ( size-adjusted BMC ) were measured at baseline and after 1 y. RESULTS There was no significant effect modification of baseline habitual calcium intake on the relation between calcium supplementation and height , weight , BMC , size-adjusted BMC , BA , BMD , or alkaline phosphatase .  Calcium supplementation had an effect on BMD ( 0.8 % ; P = 0.049 ) and tended to show signs of an effect on size-adjusted BMC ( 0.5 % ; P = 0.08 ) . CONCLUSION A modest effect of calcium supplementation on BMD was shown . However , the effect was independent of habitual calcium intake BACKGROUND Osteoporosis may be prevented or delayed by maximizing peak bone mass through diet modification and physical activity during adolescence . OBJECTIVE We studied whether increases in calcium intake and physical activity effectively increase the bone mineral status of adolescent girls aged 16 - 18 y. DESIGN We conducted a 15.5-mo study of calcium supplementation ( 1000 mg Ca/d as carbonate ) in 144 adolescent girls aged 17.3 + /- 0.3 y ( + /- SD ) . The subjects were r and omly allocated to an exercise ( three 45-min exercise-to-music classes/wk during term time ) or nonexercise group . Dual-energy X-ray absorptiometry of the whole body , spine , forearm , and hip was performed before and after intervention . RESULTS The mean ( + /- SD ) percentage of subjects compliant with supplement taking was 70 + /- 27 % and with exercise class attendance was 36 + /- 25 % . Baseline calcium intake was 938 + /- 411 mg/d . Calcium supplementation significantly increased size-adjusted bone mineral content . The effect was stronger in subjects with good compliance ( percentage difference + /- SE ) : whole body , 0.8 + /- 0.3 % ( P < or = 0.01 ) ; lumbar spine , 1.9 + /- 0.5 % ( P < or = 0.001 ) ; ultradistal radius , 1.3 + /- 0.6 % ( P < or = 0.05 ) ; total hip , 2.7 + /- 0.6 % ( P < or = 0.001 ) ; femoral neck , 2.2 + /- 0.7 % ( P < or = 0.001 ) ; trochanter , 4.8 + /- 0.9 % ( P < or = 0.001 ) . Attendance at > 50 % of the exercise sessions was significant at the total hip ( 1.4 + /- 0.7 % ; P < or = 0.05 ) and trochanter ( 2.6 + /- 1.2 % ; P < or = 0.05 ) . CONCLUSIONS Calcium supplementation and exercise enhanced bone mineral status in adolescent girls . Whether this is a lasting benefit , leading to the optimization of peak bone mass and a reduction in fracture risk , needs to be determined BACKGROUND Rural Gambian children have poor growth , delayed puberty , a low bone mineral content , and a low calcium intake . OBJECTIVE We investigated the effect of a calcium supplement on bone mineral accretion in rural Gambian children . DESIGN A r and omized , double-blind , placebo-controlled study was conducted in 160 children ( 80 boys , 80 girls ) aged 8.3 - 11.9 y.  Bone mineral content ( BMC ) , bone mineral density ( BMD ) , and BMC adjusted for bone width , body weight , and height ( size-adjusted BMC ) were measured at the midshaft and distal radius . Each child received either 1000 mg Ca/d ( as calcium carbonate ) or a placebo 5 d/wk for 12 mo . Supplementation increased calcium intake from 342 to 1056 mg/d ( 8.6 to 26.4 mmol/d ) . RESULTS Calcium supplementation result ed in a higher BMC , BMD , and size-adjusted BMC ( & xmacr ; difference + /- SE ) : midshaft radius- BMC ( 3.0 + /- 1.4 % ; P = 0.034 ) , BMD ( 4.5 + /- 0.9 % ; P < /= 0.0001 ) , and size-adjusted BMC ( 4.6 + /- 0.9 % ; P < /= 0.0001 ) ; distal radius- BMC ( 8 . 4 + /- 3.2 % ; P = 0.009 ) , BMD ( 7.0 + /- 2.7 % ; P = 0.011 ) , and size-adjusted BMC ( 5.5 + /- 2.7 % ; P = 0.042 ) . Supplementation had no significant effect on height , weight , or bone width at the midshaft radius or distal radius . At the end of the study , the calcium group had a significantly lower mean plasma osteocalcin concentration than the placebo group after adjustment for baseline concentration , sex , and pubertal status ( -21. 
    Output:
    
agent
There was no effect of calcium supplementation  on femoral neck or lumbar spine BMD .
There was no evidence of effect modification by baseline calcium intake , sex , ethnicity , physical activity or pubertal stage .
While there is a small effect of calcium supplementation in the upper limb , the increase in BMD which results is unlikely to result in a clinical ly significant decrease in fracture risk .
The results do not support the use of calcium supplementation  in healthy children as a public health intervention .
These results can not be extrapolated to children with medical conditions affecting bone metabolism
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective . To examine how cumulative teenage sports histories and time-averaged  teenage calcium intake are related to total body bone mineral gain  between ages 12 and 18 years and to proximal femur bone mineral density ( BMD ) at age 18 years . Design . Longitudinal . Setting . University Hospital and local suburban community in Central Pennsylvania . Study Participants . Eighty-one white females in the ongoing Penn State Young Women 's Health Study . Outcome Measures . Total body and proximal femur ( hip ) bone measurements by dual energy radiograph absorptiometry ; nutrient intakes  , including  calcium  , from 33 days of prospect i ve food records collected at regular intervals between ages 12 and 18 years ; and self-reported sports – exercise scores  between ages 12 and 18 years . Results . Cumulative sports – exercise scores between ages 12 and 18 years were associated with hip BMD at age 18 years ( r = .42 ) but were not related to total body bone mineral gain . Time-averaged daily  calcium  intake , which ranged from 500 to 1500 mg/day in this cohort was not associated with hip BMD at age 18 years , or with total body bone mineral gain at age 12 through 18 years . Conclusions . The amount of physical activity that distinguishes a primarily sedentary teenager from one who engages in some form of exercise on a nearly daily basis is related to a significant increase in peak hip BMD We have previously demonstrated a negative impact on peak bone mass in girls with precocious puberty treated with GnRH agonist ( GnRHa ) .  Several studies have shown that a high calcium intake positively influences bone mass in prepubertal girls and leads to a higher peak bone mass . The aim of this study was to evaluate the effect of calcium supplementation in girls with precocious puberty during GnRHa treatment .  Forty girls affected by true central precocious puberty and treated with the GnRHa triptorelin were studied for 2 yr . After diagnosis , the patients were r and omly assigned to three groups : group A , treated only with GnRHa ; group B , treated for 12 months solely with GnRHa and then supplemented with calcium gluconolactate/carbonate ( 1 g calcium/day in two doses ) for 12 months ; and group C , treated from the beginning with combined GnRHa and calcium .  Bone mineral density ( BMD ) at the lumbar spine was measured by dual energy x-ray absorptiometry at the beginning of the study and after 12 and 24 months and was expressed as the calculated true volumetric density ( BMDv ) in milligrams per cm3 . Group A showed a decrease in absolute BMDv levels , in SD score for chronological age ( CA ) , and even more in SD score for bone age ( BA ) . Group B showed the same behavior during the first year , but this trend was reversed in the second year , when calcium supplementation was added to GnRHa treatment . Group C showed an increase in absolute BMDv levels and in SD score for CA and BA . BMDv variations ( expressed as absolute values , SD score for CA , and SD score for BA ) became statistically significant at 24 months between groups C and A ( P = 0.036 , P = 0.032 , and P = 0.025 , respectively ) . The behavior of the lumbar spine BMDv in the three groups is consistent with a positive effect of calcium supplementation during GnRHa treatment . In calcium-supplemented patients , the normal process of bone mass accretion at puberty is preserved despite GnRHa treatment . Therefore , the reduction in BMD during GnRHa treatment in girls with precocious puberty is at least completely reversible and preventable if calcium supplementation is associated from the beginning Carbonated beverages have been reported to increase fracture risk in children but the mechanism is unclear . The aim of this population -based case-control study was to investigate the association between soft drink and milk consumption , physical activity , bone mass , and upper limb fractures in children aged 9–16 years . A total of 206 fracture cases and 206 r and omly selected individually matched controls were studied . There were 47 h and fractures ; 128 wrist and forearm fractures , and 31 upper arm fractures . An interviewer-administered question naire was utilized to retrospectively assess last-year physical activity ( including television , computer , and video watching ) and to recall the average weekly consumption of milk , colas , and total carbonated drinks .  Bone mass at the spine , hip , and total body was assessed by dual-energy X-ray absorptiometry ( DXA ) and metacarpal morphometry . For total fractures , none of the above drink types was significantly different between cases and controls . For wrist and forearm fractures , there was a positive association between cola drink consumption and fracture risk ( OR 1.39/unit , 95 % CI : 1.01 , 1.91 ) . Cola consumption was significantly correlated with television , computer , and video watching ( r = 0.20 , P = 0.001 ) but not bone mineral density or milk drinks . After adjustment for television , computer , and video watching and bone mineral density , the association between cola drinks and fracture risk became nonsignificant ( OR 1.31/unit , 95 % CI : 0.94 , 1.83 ) . No association with other fracture sites was observed . In conclusion , cola , but not total carbonated beverage consumption , is associated with  increased wrist and forearm fracture risk in children . However , this association is not independent of other factors and appears to be mediated by television watching and bone mineral density but not by decreased milk intake Over the past 20 years , orally administered biphosphonates have been used extensively in the management of a number of common skeletal disorders of different etiology . Recently , in clinical practice , in a number of cases in whom oral therapy is insufficient or contraindicated , intravenous administration of pamidronate presents an alternative therapeutic option . In order to investigate the clinical and radiological effects of cyclic intravenous pamidronate administration in children with osteogenesis imperfecta , a prospect i ve open study of pamidronate treatment was undertaken in a cohort of eight bed-bounded ( 3.6 - 13.8 years ) patients with severe osteoporosis and vertebral deformities .  Pamidronate was administered at a dose of 0.5 mg/kg/ day for three days . Tri-monthly cyclic intravenous infusions were performed over-one year . Bone density , verebral corpus heights , estimated volumetric bone density and biochemical measurements were analyzed . Side effects of the therapy were determined via question naire . Significant reductions in the number of bone fractures and pain were observed in all patients . Ambulation scores were significantly altered and seven of eight patients became independent . Serum alkaline phosphatase levels decreased significantly . Lumbar X-ray and densitometry showed a striking improvement by the end of the treatment period . Even spaced dense lines corresponding to infusion periods were observed on roentgenograms of the radio-ulnar region . Pubertal progression and growth velocity were not affected inversely during therapy . Although we did not observe any severe side effect , one patient 's blood urea nitrogen level was altered slightly . In conclusion , one year cyclical pamidronate treatment seems to be effective and safe in improving bone mineralization and in reducing fracture incidence in severe osteoporosis BACKGROUND There is no agreement on how much calcium young girls need for optimal bone mineralization . OBJECTIVE We evaluated whether the effect of calcium supplementation on whole-body bone mineral accretion depends on habitual calcium intake . DESIGN This was a r and omized , double-blind , placebo-controlled , 1-y calcium intervention study of girls aged 12 - 14 y selected from a larger group according to habitual calcium intake : subgroup A ( n = 60 ) habitually consumed 1000 - 1307 mg/d ( 40th-60th percentile ) , and subgroup B ( n = 53 ) habitually consumed < 713 mg/d ( < 20th percentile ) . The girls from each subgroup were r and omly assigned to receive either 500 mg Ca/d or placebo .  Whole-body bone mineral content ( BMC ) , bone area ( BA ) , bone mineral density ( BMD ) , and BMC adjusted for BA , height , and weight ( size-adjusted BMC ) were measured at baseline and after 1 y. RESULTS There was no significant effect modification of baseline habitual calcium intake on the relation between calcium supplementation and height , weight , BMC , size-adjusted BMC , BA , BMD , or alkaline phosphatase .  Calcium supplementation had an effect on BMD ( 0.8 % ; P = 0.049 ) and tended to show signs of an effect on size-adjusted BMC ( 0.5 % ; P = 0.08 ) . CONCLUSION A modest effect of calcium supplementation on BMD was shown . However , the effect was independent of habitual calcium intake BACKGROUND Osteoporosis may be prevented or delayed by maximizing peak bone mass through diet modification and physical activity during adolescence . OBJECTIVE We studied whether increases in calcium intake and physical activity effectively increase the bone mineral status of adolescent girls aged 16 - 18 y. DESIGN We conducted a 15.5-mo study of calcium supplementation ( 1000 mg Ca/d as carbonate ) in 144 adolescent girls aged 17.3 + /- 0.3 y ( + /- SD ) . The subjects were r and omly allocated to an exercise ( three 45-min exercise-to-music classes/wk during term time ) or nonexercise group . Dual-energy X-ray absorptiometry of the whole body , spine , forearm , and hip was performed before and after intervention . RESULTS The mean ( + /- SD ) percentage of subjects compliant with supplement taking was 70 + /- 27 % and with exercise class attendance was 36 + /- 25 % . Baseline calcium intake was 938 + /- 411 mg/d . Calcium supplementation significantly increased size-adjusted bone mineral content . The effect was stronger in subjects with good compliance ( percentage difference + /- SE ) : whole body , 0.8 + /- 0.3 % ( P < or = 0.01 ) ; lumbar spine , 1.9 + /- 0.5 % ( P < or = 0.001 ) ; ultradistal radius , 1.3 + /- 0.6 % ( P < or = 0.05 ) ; total hip , 2.7 + /- 0.6 % ( P < or = 0.001 ) ; femoral neck , 2.2 + /- 0.7 % ( P < or = 0.001 ) ; trochanter , 4.8 + /- 0.9 % ( P < or = 0.001 ) . Attendance at > 50 % of the exercise sessions was significant at the total hip ( 1.4 + /- 0.7 % ; P < or = 0.05 ) and trochanter ( 2.6 + /- 1.2 % ; P < or = 0.05 ) . CONCLUSIONS Calcium supplementation and exercise enhanced bone mineral status in adolescent girls . Whether this is a lasting benefit , leading to the optimization of peak bone mass and a reduction in fracture risk , needs to be determined BACKGROUND Rural Gambian children have poor growth , delayed puberty , a low bone mineral content , and a low calcium intake . OBJECTIVE We investigated the effect of a calcium supplement on bone mineral accretion in rural Gambian children . DESIGN A r and omized , double-blind , placebo-controlled study was conducted in 160 children ( 80 boys , 80 girls ) aged 8.3 - 11.9 y.  Bone mineral content ( BMC ) , bone mineral density ( BMD ) , and BMC adjusted for bone width , body weight , and height ( size-adjusted BMC ) were measured at the midshaft and distal radius . Each child received either 1000 mg Ca/d ( as calcium carbonate ) or a placebo 5 d/wk for 12 mo . Supplementation increased calcium intake from 342 to 1056 mg/d ( 8.6 to 26.4 mmol/d ) . RESULTS Calcium supplementation result ed in a higher BMC , BMD , and size-adjusted BMC ( & xmacr ; difference + /- SE ) : midshaft radius- BMC ( 3.0 + /- 1.4 % ; P = 0.034 ) , BMD ( 4.5 + /- 0.9 % ; P < /= 0.0001 ) , and size-adjusted BMC ( 4.6 + /- 0.9 % ; P < /= 0.0001 ) ; distal radius- BMC ( 8 . 4 + /- 3.2 % ; P = 0.009 ) , BMD ( 7.0 + /- 2.7 % ; P = 0.011 ) , and size-adjusted BMC ( 5.5 + /- 2.7 % ; P = 0.042 ) . Supplementation had no significant effect on height , weight , or bone width at the midshaft radius or distal radius . At the end of the study , the calcium group had a significantly lower mean plasma osteocalcin concentration than the placebo group after adjustment for baseline concentration , sex , and pubertal status ( -21. 
    Output:
    