“Vitamin D3 and Calcium to Prevent Hip Fractures in Elderly Women”, 1992-12-03 (; backlinks; similar):
Background: Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known.
Method: We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3,270 healthy ambulatory women (mean [±SD] age, 84±6 years). Each day for 18 months, 1,634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 μg (800 IU) of vitamin D3, and 1,636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at baseline and after 18 months in 56 women.
Results: Among the women who completed the 18-month study, the number of hip fractures was 43% lower (p = 0.043) and the total number of nonvertebral fractures was 32% lower (p = 0.015) among the women treated with vitamin D3 and calcium than among those who received placebo. The results of analyses according to active treatment and according to intention to treat were similar. In the vitamin D3—calcium group, the mean serum parathyroid hormone concentration had decreased by 44% from the baseline value at 18 months (p < 0.001) and the serum 25(OH)D concentration had increased by 162% over the baseline value (p < 0.001). The bone density of the proximal femur increased 2.7% in the vitamin D3—calcium group and decreased 4.6% in the placebo group (p < 0.001).
Conclusion: Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women.