Exercise combined with vitamin D supplementation has additive health effects on SPPB and stair climbing in older adults: a scope review of randomized controlled trials.

This scoping review aimed to evaluate the effect of exercise combined with vitamin D supplementation on skeletal muscle health in older individuals. We implemented a systematic search of electronic databases, including PubMed, the Cochrane Library, Web of Science, and Embase, was conducted from the time of library construction to January 2024. Eligible studies were randomized controlled trials (RCTs) including men and women aged 65 years or mean age 65 years; exercise training and vitamin D supplementation; outcomes of muscular strength, function, muscular power, body composition, and quality of life; and results compared with those of exercise intervention alone. The results showed 13 studies including 1483 participants were identified. The proportions of male and female sex were 22.05% and 77.95%, respectively. Exercise intervention methods included resistance exercises and multimodal exercise training. All vitamin D interventions involved supplementation with vitamin D₃. A significant increase was identified in short physical performance battery (SPPB) and stair climbing but not in skeletal muscle mass, skeletal strength, the timed up and go (TUG) test, and gait speed in older adults after exercise combined with vitamin D supplementation. In conclusion，exercise combined with vitamin D supplementation has additive health effects on SPPB and stair climbing. Furthermore, when vitamin D was deficient at baseline, the combined effect of exercise and vitamin D intervention significantly increased the TUG and gait speed in older adults. In future RCTs on this topic, baseline vitamin D nutritional status, health condition, and sex should be considered.