Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment .
REVIEW ER 'S CONCLUSIONS Calcium supplementation alone has a small positive effect on bone density .
The data show a trend toward reduction in vertebral fractures , but it is unclear if calcium reduces the incidence of non vertebral fractures
BACKGROUND Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy ( Kanis 1989 ; Nordin 1990 ) .
The Food and Drug Administration in the US has permitted a bone health cl aim for calcium-rich foods , and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis .
OBJECTIVES To assess the effects of calcium on bone density and fractures in postmenopausal women .
The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women.
The etiology of age-related bone loss is unclear but both lack of exercise and dietary calcium deficiency have been implicated in its causation . This 2-year r and omized placebo-controlled study was design ed to examine the effects of increased dietary calcium and exercise in 168 women who were more than 10 years postmenopausal . The subjects were r and omized into one of 4 groups : placebo , milk powder containing 1 g of calcium , calcium tablets 1 g/night , and calcium tablets 1 g/night and an exercise regimen . The exercise group aim ed to undertake 4 h of extra weight-bearing exercise per week and were undertaking 10 % more activity than other groups at 2 years . Bone mineral density at the lumbar spine , three hip sites , and two sites of the tibia close to the ankle joint were measured at 6 month intervals .  Dietary intake  was evaluated by a weighed food record ,  exercise  was evaluated by an exercise diary , and blood and urine sample s were obtained to examine effects on calcium homeostasis . Individual data points were compared using repeated measures ANOVA and least squares regression . Calcium supplementation by either the calcium tablets or the milk powder result ed in cessation of bone loss at the intertrochanteric hip site ( placebo , calcium tablets , calcium and exercise , milk powder -0.81 , + 0.17 , + 0.23 , and + 0.07 % per year , respectively ; p < 0.05 for all supplementation groups compared with placebo ) with similar results at the trochanteric hip site . The calcium and exercise group had less bone loss at the femoral neck site when compared with calcium supplementation alone ( placebo , calcium tablets , calcium and exercise , milk powder -0.67 , -0.18 , + 0.28 , and -0.18 % per year , respectively ; p < 0.05 for calcium and exercise compared with calcium alone ) . There was a significant reduction in the rate of bone loss at the ultradistal site of the tibia ( placebo , calcium tablets , calcium and exercise , milk powder -2.5 , -1.6 , -1.0 , and -1.5 % per year , respectively ; p < 0.05 for all supplementation groups compared with placebo ) . There was no significant bone loss at the spine site in any group . ( ABSTRACT TRUNCATED AT 250 WORDS
Calcium was more effective than placebo in reducing rates of bone loss after two or more years of treatment .
REVIEW ER 'S CONCLUSIONS Calcium supplementation alone has a small positive effect on bone density .
The data show a trend toward reduction in vertebral fractures , but it is unclear if calcium reduces the incidence of non vertebral fractures
BACKGROUND Although calcium is one the simplest and least expensive strategies for preventing osteoporotic fractures calcium supplementation is nevertheless not without controversy ( Kanis 1989 ; Nordin 1990 ) .
The Food and Drug Administration in the US has permitted a bone health cl aim for calcium-rich foods , and the NIH in its Consensus Development Process approved a statement that high calcium intake reduces the risk of osteoporosis .
OBJECTIVES To assess the effects of calcium on bone density and fractures in postmenopausal women .