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: Dietary data from a prospect i ve study were used to relate factors influencing calcium balance ( estimates of dietary calcium intake , protein intake from nondairy animal sources ( meat , fish , and eggs ) , and coffee consumption ) to the incidence of  hip fracture . During the years 1977 - 1983 , women and men born between 1925 and 1940 and living in one of three Norwegian counties were invited to a  cardiovascular screening that included a dietary survey . The attendance rate at screening was 91.1 % , and 90.7 % of these persons ( 19,752 women and 20,035 men ) filled in and returned a semiquantitative dietary question naire . This cohort was followed for an average of 11.4 years ( range , 0.01 - 13.8 years ) with respect to hip fracture , defined as cervical or trochanteric fracture . During follow-up , 213 hip fractures were identified , excluding fractures associated with high-energy trauma and metastatic bone disease . There was no clear association between  calcium intake or nondairy animal protein intake  and hip fracture in this cohort . However , an elevated risk of fracture was found in women with a high intake of protein from nondairy animal sources in the presence of low calcium intake ( relative risk = 1.96 ( 95 % confidence interval 1.09 - 3.56 ) for the highest quarter of nondairy protein intake and the lowest quarter of calcium intake vs. the three lower quarters of protein intake and the three higher quarters of calcium intake ) . Women who drank nine or more cups of coffee per day also had an increased risk of fracture , while there was no association between coffee consumption and hip fracture in men . Although these findings do not necessarily imply causal relations , they suggest the presence of risk factors for hip fracture that act through a negative calcium balance in this population BACKGROUND The effect of meat protein on calcium retention at different calcium intakes is unresolved . OBJECTIVE The objective was to test the effect of dietary protein on calcium retention at low and high intakes of calcium . DESIGN In a r and omized controlled feeding study with a 2 x 2 factorial crossover design , healthy postmenopausal women ( n = 27 ) consumed either approximately 675 or approximately 1510 mg Ca/d , with both low and high protein ( providing 10 % and 20 % energy ) for 7 wk each , separated by a 3-wk washout period . After 3 wk , the entire diet was extrinsically labeled with (47)Ca , and isotope retention was monitored by whole-body scintillation counting . Clinical markers of calcium and bone metabolism were measured . RESULTS High compared with low dietary protein significantly increased calcium retention from the low-calcium ( 29.5 % compared with 26.0 % absorbed ) but not the high-calcium diet ( 18 % absorbed ) . For the low-calcium diet , this effect nearly balanced a protein-related 0.5-mmol/d greater urinary calcium excretion . Protein-related calciuretic effects were independent of dietary calcium . Testing at 1 , 2 , 3 , 5 , and 7 wk showed no long-term adaptation in urinary acidity or urinary calcium excretion . High compared with low dietary protein decreased urinary deoxypyridinoline and increased serum insulin-like growth factor I without affecting parathyroid hormone , osteocalcin , bone-specific alkaline phosphatase , or tartrate-resistant acid phosphatase . CONCLUSIONS In healthy postmenopausal women , a moderate increase in dietary protein , from 10 % to 20 % of energy , slightly improved calcium absorption from a low-calcium diet , nearly compensating for a slight increase in urinary calcium excretion . Under practical dietary conditions , increased dietary protein from animal sources was not detrimental to calcium balance or short-term indicators of bone health High dietary acid load ( DAL ) may be detrimental to bone mineral density ( BMD ) . The objectives of the study were to : ( 1 ) evaluate the cross-sectional relation between DAL and BMD ; and ( 2 ) determine whether calcium intake modifies this association . Men ( n = 1218 ) and women ( n = 907 ) aged ≥60 years were included from the National Health and Nutrition Examination Survey 2005 - 2008 .  Nutrient intake from 2 , 24-hour recalls was used to calculate net endogenous acid production ( NEAP ) and potential renal acid load  ( PRAL ) ( mEq/d ) . PRAL was calculated from dietary calcium ( PRALdiet ) and diet + supplemental calcium ( PRALtotal ) . Tests for linear trend in adjusted mean BMD of the hip and lumbar spine were performed across energy-adjusted NEAP and PRAL quartiles . Modification by calcium intake ( dietary or total ) above or below 800 mg/d was assessed by interaction terms . Overall , mean age was 69 ± 0.3 years . Among women , there was no association between NEAP and BMD  . PRALdiet was positively associated with proximal femur BMD ( p trend = 0.04 ) . No associations were observed with PRALtotal at any BMD site ( p range , 0.38 - 0.82 ) . Among men , no significant associations were observed between BMD and NEAP or PRAL . However , an interaction between PRALdiet and calcium intake was observed with proximal femur BMD ( p = 0.08 ) . An inverse association between PRALdiet and proximal femur BMD was detected among men with < 800 mg/d dietary calcium ( p = 0.02 ) ; no associations were found among men with ≥800 mg/d ( p = 0.98 ) . A significant interaction with PRALtotal was not observed . In conclusion , when supplemental calcium is considered , there is no association between DAL and  BMD among adults . Men with low dietary calcium showed an inverse relation with PRAL at the proximal femur ; in women no interaction was observed . This study highlights the importance of calcium intake in counteracting the adverse effect of DAL on bone health . Further research should determine the relation between DAL and change in BMD with very low calcium intake Purpose In Malaysia , hip fracture incidence is higher in Chinese women than other ethnic groups . This study compared the effects of a high-calcium vitamin D fortified milk with added FOS-inulin versus regular milk over 1 year on aspects of bone health in Chinese postmenopausal women in Malaysia . Methods One-hundred and twenty-one women ( mean age 59 ( ± 4 ) years ) were r and omized into two groups : control ( n = 60 ; regular milk , 428 mg calcium per day ) or intervention ( n = 61 ; fortified milk at 1200 mg calcium , 96 mg magnesium , 2.4 mg zinc , 15 μg vitamin D and 4 g FOS-inulin per day ) . At baseline , weeks 12 , 24 , 36 and 52 , parathyroid hormone ( PTH ) , C-Telopeptide of Type I Collagen ( CTx-1 ) , Procollagen I Intact N-Terminal propeptide ( PINP ) and vitamin D levels were assessed . Bone density ( BMD ) was measured at baseline and week 52 using a GE Lunar iDXA . Results Body mass index , lumbar spine and femoral neck BMD did not differ between groups at baseline . Over 52 weeks , mean plasma 25 ( OH ) D3 levels increased to 74.8 nmol/L ( intervention group ) or remained at 63.1 nmol/L ( control group ) ( p < 0.001 between groups ) . PTH levels increased in the control group ( p = 0.001 ) . The intervention result ed in a significant suppression of CTx-1 and PINP at p = 0.018 and p = 0.004 . Femoral neck BMD remained stable in the intervention group but decreased significantly in the controls , with a borderline treatment effect ( p = 0.07 ) . Conclusion Compared with regular milk , the fortified milk suppressed bone turnover markers and tended to increase femoral neck BMD Context We hypothesize that endogenous sex steroids are associated with fracture risk independent of race/ethnicity . Design and Setting We performed a nested case-control study within the prospect i ve Women 's Health Initiative Observational Study . Incident nonspine fractures were identified in 381 black , 192 Hispanic , 112 Asian , and 46 Native American women over an average of 8.6 years . A r and om sample of 400 white women who experienced an incident fracture was chosen . One control was selected per case and matched on age , race/ethnicity , and blood draw date .  Bioavailable estradiol ( BioE2 ) , bioavailable testosterone ( BioT ) , and sex hormone-binding globulin ( SHBG ) were measured using baseline fasting serum . Conditional logistic regression models calculated the odds ratio ( OR ) and 95 % confidence interval ( CI ) of fracture across tertiles of hormone . Results In multivariable and race/ethnicity-adjusted models , higher BioE2 ( > 8.25 pg/mL ) and higher BioT ( > 13.3 ng/dL ) were associated with decreased risk of fracture ( OR , 0.65 ; 95 % CI , 0.50 to 0.85 ; P trend = 0.001 and OR , 0.76 ; 95 % CI , 0.60 to 0.96 ; P trend = 0.02 , respectively ) . The interaction term between race/ethnicity and either BioE2 or BioT was not significant . There was no association between SHBG and fracture risk . In models stratifying by race/ethnicity , higher BioE2 was associated with a lower risk of fracture in both white women ( OR , 0.56 ; 95 % CI , 0.36 to 0.87 ) and black women ( OR , 0.61 ; 95 % CI , 0.39 to 0.96 ) . Higher BioT was associated with a significantly lower fracture risk in only black women ( OR , 0.65 ; 95 % CI , 0.43 to 1.00 ) , P trend = 0.03 . Conclusions Serum BioE2 and BioT are associated with fracture risk in older women irrespective of race/ethnicity and independent of established risk factors for fracture BACKGROUND Short trials of calcium supplementation show that it reduces loss of bone density in postmenopausal women ; longer observational studies do not generally find a lower risk of hip fracture with higher-calcium diets . Fewer studies have focused on vitamin D in preventing postmenopausal osteoporosis or fractures . OBJECTIVE We assessed relations between postmenopausal hip fracture risk and calcium , vitamin D , and milk consumption . DESIGN In an 18-y prospect i ve analysis in 72 337 postmenopausal women , dietary intake and nutritional supplement use were assessed at baseline in 1980 and up date d several times during follow-up . We identified 603 incident hip fractures result ing from low or moderate trauma .  Relative risks ( RRs ) from proportional hazards models were controlled for other dietary and nondietary factors . RESULTS Women consuming > or = 12.5 microg vitamin D/d from food plus supplements had a 37 % lower risk of hip fracture ( RR = 0.63 ; 95 % CI : 0.42 , 0.94 ) than did women consuming < 3.5 microg/d . Total calcium intake was not associated with hip fracture risk ( RR = 0.96 ; 95 % CI : 0.68 , 1.34 for > or = 1200 compared with < 600 mg/d ) . Milk consumption was also not associated with a lower risk of hip fracture ( P for trend = 0.21 ) . CONCLUSIONS An adequate vitamin D intake is associated with a lower risk of osteoporotic hip fractures in postmenopausal women . Neither milk nor a high-calcium diet appears to reduce risk . Because women commonly consume less than the recommended intake of vitamin D , supplement use or dark fish consumption may be prudent The aim of this study was to investigate whether a product rich in transgalactooligosaccharides ( TOS , Elix'or ) stimulates true Ca absorption in postmenopausal women . The study was a double-blind , r and omized crossover study , consisting of two 9-d treatment periods separated by a 19-d washout period . During the treatment periods , 12 subjects  drank 200 mL yogurt drink twice ( at breakfast and lunch ) containing either TOS ( 20 g/d ) or the reference substance , sucrose . On d 8 of each treatment period , (44)Ca and (48)Ca were administered orally and intravenously , respectively . Before and during the 36 h after isotope administration , urine was collected and the ratios of isotopes present were measured by inductively coupled plasma mass spectrometry ( ICP-MS ) . From the isotope enrichments , true calcium absorption was calculated . TOS increased true calcium absorption 16 % , from ( mean + /- SD ) 20.6 + /- 7.0 % during the reference treatment to 23 
    Output:
    
agent
In the present meta- analysis , reductions in the risk of hip fracture  with milk consumption were only observed among American adults , but not among Sc and inavian adults , possibly because milk products are more commonly fortified with vitamin D in the former population than in Sc and inavian countries .
The reduction in the risk of hip fracture was also observed with yogurt consumption , which is often associated with healthy lifestyles and dietary patterns that contribute to improved bone health .
Fueling this uncertainty , the elevated  risk of hip fracture  in association with  milk consumption was observed in a cohort of Swedish women .
The cumulative evidence from prospect i ve cohort studies reassuringly suggests that the risk of hip fracture may not be elevated among people who consume milk , yogurt , and cheese , and that a greater consumption of milk or yogurt may even be associated with a lower risk of hip fracture depending on the factors that may differ across the population of interest
***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: Dietary data from a prospect i ve study were used to relate factors influencing calcium balance ( estimates of dietary calcium intake , protein intake from nondairy animal sources ( meat , fish , and eggs ) , and coffee consumption ) to the incidence of  hip fracture . During the years 1977 - 1983 , women and men born between 1925 and 1940 and living in one of three Norwegian counties were invited to a  cardiovascular screening that included a dietary survey . The attendance rate at screening was 91.1 % , and 90.7 % of these persons ( 19,752 women and 20,035 men ) filled in and returned a semiquantitative dietary question naire . This cohort was followed for an average of 11.4 years ( range , 0.01 - 13.8 years ) with respect to hip fracture , defined as cervical or trochanteric fracture . During follow-up , 213 hip fractures were identified , excluding fractures associated with high-energy trauma and metastatic bone disease . There was no clear association between  calcium intake or nondairy animal protein intake  and hip fracture in this cohort . However , an elevated risk of fracture was found in women with a high intake of protein from nondairy animal sources in the presence of low calcium intake ( relative risk = 1.96 ( 95 % confidence interval 1.09 - 3.56 ) for the highest quarter of nondairy protein intake and the lowest quarter of calcium intake vs. the three lower quarters of protein intake and the three higher quarters of calcium intake ) . Women who drank nine or more cups of coffee per day also had an increased risk of fracture , while there was no association between coffee consumption and hip fracture in men . Although these findings do not necessarily imply causal relations , they suggest the presence of risk factors for hip fracture that act through a negative calcium balance in this population BACKGROUND The effect of meat protein on calcium retention at different calcium intakes is unresolved . OBJECTIVE The objective was to test the effect of dietary protein on calcium retention at low and high intakes of calcium . DESIGN In a r and omized controlled feeding study with a 2 x 2 factorial crossover design , healthy postmenopausal women ( n = 27 ) consumed either approximately 675 or approximately 1510 mg Ca/d , with both low and high protein ( providing 10 % and 20 % energy ) for 7 wk each , separated by a 3-wk washout period . After 3 wk , the entire diet was extrinsically labeled with (47)Ca , and isotope retention was monitored by whole-body scintillation counting . Clinical markers of calcium and bone metabolism were measured . RESULTS High compared with low dietary protein significantly increased calcium retention from the low-calcium ( 29.5 % compared with 26.0 % absorbed ) but not the high-calcium diet ( 18 % absorbed ) . For the low-calcium diet , this effect nearly balanced a protein-related 0.5-mmol/d greater urinary calcium excretion . Protein-related calciuretic effects were independent of dietary calcium . Testing at 1 , 2 , 3 , 5 , and 7 wk showed no long-term adaptation in urinary acidity or urinary calcium excretion . High compared with low dietary protein decreased urinary deoxypyridinoline and increased serum insulin-like growth factor I without affecting parathyroid hormone , osteocalcin , bone-specific alkaline phosphatase , or tartrate-resistant acid phosphatase . CONCLUSIONS In healthy postmenopausal women , a moderate increase in dietary protein , from 10 % to 20 % of energy , slightly improved calcium absorption from a low-calcium diet , nearly compensating for a slight increase in urinary calcium excretion . Under practical dietary conditions , increased dietary protein from animal sources was not detrimental to calcium balance or short-term indicators of bone health High dietary acid load ( DAL ) may be detrimental to bone mineral density ( BMD ) . The objectives of the study were to : ( 1 ) evaluate the cross-sectional relation between DAL and BMD ; and ( 2 ) determine whether calcium intake modifies this association . Men ( n = 1218 ) and women ( n = 907 ) aged ≥60 years were included from the National Health and Nutrition Examination Survey 2005 - 2008 .  Nutrient intake from 2 , 24-hour recalls was used to calculate net endogenous acid production ( NEAP ) and potential renal acid load  ( PRAL ) ( mEq/d ) . PRAL was calculated from dietary calcium ( PRALdiet ) and diet + supplemental calcium ( PRALtotal ) . Tests for linear trend in adjusted mean BMD of the hip and lumbar spine were performed across energy-adjusted NEAP and PRAL quartiles . Modification by calcium intake ( dietary or total ) above or below 800 mg/d was assessed by interaction terms . Overall , mean age was 69 ± 0.3 years . Among women , there was no association between NEAP and BMD  . PRALdiet was positively associated with proximal femur BMD ( p trend = 0.04 ) . No associations were observed with PRALtotal at any BMD site ( p range , 0.38 - 0.82 ) . Among men , no significant associations were observed between BMD and NEAP or PRAL . However , an interaction between PRALdiet and calcium intake was observed with proximal femur BMD ( p = 0.08 ) . An inverse association between PRALdiet and proximal femur BMD was detected among men with < 800 mg/d dietary calcium ( p = 0.02 ) ; no associations were found among men with ≥800 mg/d ( p = 0.98 ) . A significant interaction with PRALtotal was not observed . In conclusion , when supplemental calcium is considered , there is no association between DAL and  BMD among adults . Men with low dietary calcium showed an inverse relation with PRAL at the proximal femur ; in women no interaction was observed . This study highlights the importance of calcium intake in counteracting the adverse effect of DAL on bone health . Further research should determine the relation between DAL and change in BMD with very low calcium intake Purpose In Malaysia , hip fracture incidence is higher in Chinese women than other ethnic groups . This study compared the effects of a high-calcium vitamin D fortified milk with added FOS-inulin versus regular milk over 1 year on aspects of bone health in Chinese postmenopausal women in Malaysia . Methods One-hundred and twenty-one women ( mean age 59 ( ± 4 ) years ) were r and omized into two groups : control ( n = 60 ; regular milk , 428 mg calcium per day ) or intervention ( n = 61 ; fortified milk at 1200 mg calcium , 96 mg magnesium , 2.4 mg zinc , 15 μg vitamin D and 4 g FOS-inulin per day ) . At baseline , weeks 12 , 24 , 36 and 52 , parathyroid hormone ( PTH ) , C-Telopeptide of Type I Collagen ( CTx-1 ) , Procollagen I Intact N-Terminal propeptide ( PINP ) and vitamin D levels were assessed . Bone density ( BMD ) was measured at baseline and week 52 using a GE Lunar iDXA . Results Body mass index , lumbar spine and femoral neck BMD did not differ between groups at baseline . Over 52 weeks , mean plasma 25 ( OH ) D3 levels increased to 74.8 nmol/L ( intervention group ) or remained at 63.1 nmol/L ( control group ) ( p < 0.001 between groups ) . PTH levels increased in the control group ( p = 0.001 ) . The intervention result ed in a significant suppression of CTx-1 and PINP at p = 0.018 and p = 0.004 . Femoral neck BMD remained stable in the intervention group but decreased significantly in the controls , with a borderline treatment effect ( p = 0.07 ) . Conclusion Compared with regular milk , the fortified milk suppressed bone turnover markers and tended to increase femoral neck BMD Context We hypothesize that endogenous sex steroids are associated with fracture risk independent of race/ethnicity . Design and Setting We performed a nested case-control study within the prospect i ve Women 's Health Initiative Observational Study . Incident nonspine fractures were identified in 381 black , 192 Hispanic , 112 Asian , and 46 Native American women over an average of 8.6 years . A r and om sample of 400 white women who experienced an incident fracture was chosen . One control was selected per case and matched on age , race/ethnicity , and blood draw date .  Bioavailable estradiol ( BioE2 ) , bioavailable testosterone ( BioT ) , and sex hormone-binding globulin ( SHBG ) were measured using baseline fasting serum . Conditional logistic regression models calculated the odds ratio ( OR ) and 95 % confidence interval ( CI ) of fracture across tertiles of hormone . Results In multivariable and race/ethnicity-adjusted models , higher BioE2 ( > 8.25 pg/mL ) and higher BioT ( > 13.3 ng/dL ) were associated with decreased risk of fracture ( OR , 0.65 ; 95 % CI , 0.50 to 0.85 ; P trend = 0.001 and OR , 0.76 ; 95 % CI , 0.60 to 0.96 ; P trend = 0.02 , respectively ) . The interaction term between race/ethnicity and either BioE2 or BioT was not significant . There was no association between SHBG and fracture risk . In models stratifying by race/ethnicity , higher BioE2 was associated with a lower risk of fracture in both white women ( OR , 0.56 ; 95 % CI , 0.36 to 0.87 ) and black women ( OR , 0.61 ; 95 % CI , 0.39 to 0.96 ) . Higher BioT was associated with a significantly lower fracture risk in only black women ( OR , 0.65 ; 95 % CI , 0.43 to 1.00 ) , P trend = 0.03 . Conclusions Serum BioE2 and BioT are associated with fracture risk in older women irrespective of race/ethnicity and independent of established risk factors for fracture BACKGROUND Short trials of calcium supplementation show that it reduces loss of bone density in postmenopausal women ; longer observational studies do not generally find a lower risk of hip fracture with higher-calcium diets . Fewer studies have focused on vitamin D in preventing postmenopausal osteoporosis or fractures . OBJECTIVE We assessed relations between postmenopausal hip fracture risk and calcium , vitamin D , and milk consumption . DESIGN In an 18-y prospect i ve analysis in 72 337 postmenopausal women , dietary intake and nutritional supplement use were assessed at baseline in 1980 and up date d several times during follow-up . We identified 603 incident hip fractures result ing from low or moderate trauma .  Relative risks ( RRs ) from proportional hazards models were controlled for other dietary and nondietary factors . RESULTS Women consuming > or = 12.5 microg vitamin D/d from food plus supplements had a 37 % lower risk of hip fracture ( RR = 0.63 ; 95 % CI : 0.42 , 0.94 ) than did women consuming < 3.5 microg/d . Total calcium intake was not associated with hip fracture risk ( RR = 0.96 ; 95 % CI : 0.68 , 1.34 for > or = 1200 compared with < 600 mg/d ) . Milk consumption was also not associated with a lower risk of hip fracture ( P for trend = 0.21 ) . CONCLUSIONS An adequate vitamin D intake is associated with a lower risk of osteoporotic hip fractures in postmenopausal women . Neither milk nor a high-calcium diet appears to reduce risk . Because women commonly consume less than the recommended intake of vitamin D , supplement use or dark fish consumption may be prudent The aim of this study was to investigate whether a product rich in transgalactooligosaccharides ( TOS , Elix'or ) stimulates true Ca absorption in postmenopausal women . The study was a double-blind , r and omized crossover study , consisting of two 9-d treatment periods separated by a 19-d washout period . During the treatment periods , 12 subjects  drank 200 mL yogurt drink twice ( at breakfast and lunch ) containing either TOS ( 20 g/d ) or the reference substance , sucrose . On d 8 of each treatment period , (44)Ca and (48)Ca were administered orally and intravenously , respectively . Before and during the 36 h after isotope administration , urine was collected and the ratios of isotopes present were measured by inductively coupled plasma mass spectrometry ( ICP-MS ) . From the isotope enrichments , true calcium absorption was calculated . TOS increased true calcium absorption 16 % , from ( mean + /- SD ) 20.6 + /- 7.0 % during the reference treatment to 23 
    Output:
    