Vitamin D supplementation associated with 12-weeks multimodal training in older women with low bone mineral density: A randomized double-blind placebo-controlled trial.

Abstract

To evaluate the influence of vitamin D supplementation with a multimodal exercise program on postural balance and muscle strength in older women with low bone mineral density (BMD) and vitamin D insufficiency. 12-week, randomized, double-blind, placebo-controlled clinical trial. Total of 422 subjects were screened for participation, and 46 met the inclusion criteria. Those were randomized into an experimental group (EG; n=23) and control group (CG; n=23). At the time of enrollment, all subjects had low BMD, vitamin D insufficiency, and were not practicing resistance exercise. Muscle strength assessments were performed by the 30-s sit to stand test; 15-steps climbing test; handgrip dynamometer and knee muscle strength using an isokinetic dynamometer at 60°/sec. Postural balance was clinically evaluated by the MiniBESTest and by a force platform. Dynamic balance was assessed by standing up from a chair and walk over a step, using also a force platform. In the EG, vitamin D levels increased in the post-treatment period (P<0.001) whereas in CG levels remained unchanged (P=0.86). Both groups improved muscular strength in the dynamometry isokinetic test: flexors PT/BW - right (P<0.02) and left side (P<0.04). In the dynamic postural balance during the task to step up over: the Lift Up Left was better in the CG (P=0.01); the Moment Time left was better in the CG (P=0.01); the Impact index left was better in the EG (P=0.01). The Mini-BESTest - both groups improved the postural balance test (P<0.001). Vitamin D supplementation associated with multimodal exercise program did not augment muscle strength adaptation or postural balance in older women with low bone mineral density and vitamin D insufficiency.