It was not possible to determine how many studies were included in the review, or how many participants were evaluated.
Calcium and vitamin D.
Calcium supplementation was associated with a decrease in BMD loss from the radius (1.82%), femoral shaft (0.7 to 1.3%), femoral neck (0.3%), lumbar spine (2.6 to 3.92%), proximal femur (1.3%) and total body (0.9 to 1.85%). There were significant decreases in the fracture incidence observed in pre- and postmenopausal women (P=0.023 and P<0.05, respectively). However, there was no significant decrease in fracture incidence in peri-menopausal women. There were inconsistent results in the studies that evaluated the use of vitamin D for the prevention of bone fractures (the results were not given). Both calcium and vitamin D supplementation were relatively well tolerated.
The results of both the experimental and observational studies suggested that BMD was preserved in women receiving HRT. However, it was not clear if this translated into a reduction in the risk of bone fractures. Four observational studies found a significant decrease in fracture risk associated with HRT (RR ranged from 0.23 to 0.65). However, the reduction in fracture risk was not significantly significant in two RCTs. HRT was associated with serious life-threatening adverse events including an increased risk of endometrial cancer, breast cancer and acute myocardial infarction.
Alendronate and risedronate were associated with significant increases in BMD (ranging from 1.6% to 8.8%), based on patients in six studies. The increase was sustained for 5 to 7 years following treatment with alendronate, based on patients in two of the included studies. Six studies found that alendronate and risedronate were effective in reducing the risk of vertebral and nonvertebral fractures (range, where reported: 14 to 48%). Bisphosphonates were well tolerated and the most frequently reported adverse events were associated with the upper gastrointestinal tract.
Raloxifene was associated with significant increases in BMD (ranging from 0.6 to 2.2%). One study found that raloxifene was associated with a significant reduction in the risk of fracture of the lumber spine and femoral neck. The most frequent adverse events were leg cramps and peripheral oedema, while the most serious adverse event was an increased risk of thromboembolism.
The results on the effectiveness of calcitonin on BMD were conflicting. Most of the included studies found that calcitonin was associated with a significant increase in BMD (ranging from 0.5 to 5%), whereas some studies found no difference or a slight decrease. However, calcitonin was found to significantly reduce the incidence of new bone fractures compared with placebo. No safety data were provided.