Effects of Enhanced Exercise and Combined Vitamin D and Calcium Supplementation on Muscle Strength and Fracture Risk in Postmenopausal Chinese Women.

Objective To observe the effects of enhanced exercise and combined vitamin D and calcium supplementation on muscular strength and fracture occurrence in postmenopausal women with a high risk of osteoporosis.Methods Totally 614 postmenopausal women at high risk factors of osteoporosis were enrolled in Dongcheng district of Beijing and randomized into four groups:group A(control group,n=173),group B(regular Tai Chi exercise,n=171),group C(calcium 600 mg/d+VitD 800 U/d,n=139),and group D[calcium 600 mg/d+25 hydroxyl vitamin D(25OHD) 0.25 μg/d,n=131].Muscular strength was measured at baseline and one and two years after intervention.Bone turnover markers were measured at baseline and during the two-year follow-up.Falls and fractures were recorded.Results The incidence of 25OHD<50 nmol/L was approximately 92.6%.During the follow-up,the left grip strength decreased significantly two years after intervention(t=-3.252,P=0.001)in group A.Right grip strength decreased significantly in group B(t=2.460,P=0.015)while left grip strength improved significantly in group C(t=-2.051,P=0.043)one year after intervention.In group D,muscular strength in both 12-month and 24-month did not change compared with baseline(both P>0.05).Furthermore,serum procollagen type I N-terminal propeptide elevated significantly in group A(t=-2.962,P=0.004),group B(t=-2.888,P=0.005),and group C(t=-2.441,P=0.016),whereas β-C-terminal telopeptide of type I collagen decreased significantly in group B(t=2.285,P=0.024)and group D(t=2.596,P=0.011)two years after intervention.Conclusion Enhanced exercise and combined calcium vitamin D supplementation may help sustain muscle strength in postmenopausal women,while calcium and vitamin D supplementation may improve muscular strength within a short period of time.