Importance: While vitamin D supplementation and exercise are recommended for prevention of falls for older people, results regarding these 2 factors are contradictory.
Objective: To determine the effectiveness of targeted exercise training and vitamin D supplementation in reducing falls and injurious falls among older women.
Design, setting, and participants: A 2-year randomized, double-blind, placebo-controlled vitamin D and open exercise trial conducted between April 2010 and March 2013 in Tampere, Finland. Participants were 409 home-dwelling women 70 to 80 years old. The main inclusion criteria were at least 1 fall during the previous year, no use of vitamin D supplements, and no contraindication to exercise.
Interventions: Four study groups, including placebo without exercise, vitamin D (800 IU/d) without exercise, placebo and exercise, and vitamin D (800 IU/d) and exercise.
Main outcomes and measures: The primary outcome was monthly reported falls. Injurious falls and the number of fallers and injured fallers were reported as secondary outcomes. In addition, bone density, physical functioning (muscle strength, balance, and mobility), and vitamin D metabolism were assessed.
Results: Intent-to-treat analyses showed that neither vitamin D nor exercise reduced falls. Fall rates per 100 person-years were 118.2, 132.1, 120.7, and 113.1 in the placebo without exercise, vitamin D without exercise, placebo and exercise, and vitamin D and exercise study groups, respectively; however, injurious fall rates were 13.2, 12.9, 6.5, and 5.0, respectively. Hazard ratios for injured fallers were significantly lower among exercisers with vitamin D (0.38; 95% CI, 0.17-0.83) and without vitamin D (0.47; 95% CI, 0.23-0.99). Vitamin D maintained femoral neck bone mineral density and increased tibial trabecular density slightly. However, only exercise improved muscle strength and balance. Vitamin D did not enhance exercise effects on physical functioning.
Conclusions and relevance: The rate of injurious falls and injured fallers more than halved with strength and balance training in home-dwelling older women, while neither exercise nor vitamin D affected the rate of falls. Exercise improved physical functioning. Future research is needed to determine the role of vitamin D in the enhancement of strength, balance, and mobility.
Trial registration: clinicaltrials.gov Identifier: NCT00986466.