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document
The effect of calcium supplementation on bone density in premenarcheal females : a co-twin approach . The age and developmental stage at which calcium supplementation produces the greatest bone effects remain controversial . We tested the hypothesis that calcium supplementation may improve bone accrual in premenarcheal females . Fifty-one pairs of premenarcheal female twins ( 27 monozygotic and 24 dizygotic ; mean +/- sd age , 10.3 +/- 1.5 yr ) participated in a randomized , single-blind , placebo-controlled trial with one twin of each pair receiving a 1200-mg calcium carbonate ( Caltrate ) supplement . Areal bone mineral density ( aBMD ) was measured at baseline and 6 , 12 , 18 and 24 months . There were no within-pair differences in height , weight , or calcium intake at baseline . Calcium supplementation was associated ( P < 0.05 ) with increased aBMD compared with placebo , adjusted for age , height , and weight at the following time points from baseline : total hip , 6 months ( 1.9 % ) , 12 months ( 1.6 % ) , and 18 months ( 2.4 % ) ; lumbar spine , 12 months ( 1.0 % ) ; femoral neck , 6 months ( 1.9 % ) . Adjusted total body bone mineral content was higher in the calcium group at 6 months ( 2.0 % ) , 12 months ( 2.5 % ) , 18 months ( 4.6 % ) , and 24 months ( 3.7 % ) , respectively ( all P < 0.001 ) . Calcium supplementation was effective in increasing aBMD at regional sites over the first 12-18 months , but these gains were not maintained to 24 months .
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Intervention_Pharmacological
calcium supplementation
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Intervention_Pharmacological
calcium supplementation
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Intervention_Pharmacological
calcium supplementation
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Intervention_Control
placebo-controlled
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Intervention_Pharmacological
receiving a 1200-mg calcium carbonate ( Caltrate ) supplement .
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Intervention_Pharmacological
Calcium supplementation
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Outcome_Physical
bone accrual
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Outcome_Physical
Areal bone mineral density ( aBMD )
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Outcome_Physical
aBMD
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Outcome_Physical
Adjusted total body bone mineral content
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Outcome_Physical
aBMD
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Participant_Condition
premenarcheal females :
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Participant_Condition
within-pair differences in height , weight , or calcium intake at baseline .