Effects of vitamin D supplementation combined with resistance exercise on body composition and metabolic variables in older women: a randomized clinical trial

Abstract

Introduction Aging has a significant impact on health, leading to changes in body composition and physical functionality in older adults. Objective Given the relevance of this topic, the aim of this study was to analyze the effects of vitamin D supplementation combined with physical exercise over a 12-week period on body composition and metabolic profile in elderly women. Methods The study followed a clinical approach, employing a randomized, double-blind, placebo-controlled trial, in accordance with the guidelines established by the Consolidated Standards of Reporting Trials (CONSORT), conducted at the Movement Studies Laboratory in São Paulo, Brazil. Analyses were performed using an intention-to-treat approach with random effects regression models. The study sample consisted of 46 elderly individuals, divided into two groups with 23 participants each. The experimental group received vitamin D3 supplementation at a dose of 49,000 IU/week, while the placebo group received seven capsules of the same size, volume, and color, containing lactose but no vitamin D3. Results After analyzing the results, it was observed that the groups were homogeneous in terms of age (p = 0.7658) and BMI (p = 0.5904). The results showed differences in 25-OH vitamin D levels (p < 0.001) between the groups over time. Conclusion In conclusion, vitamin D supplementation successfully increased serum levels but failed to provide additional benefits for muscle mass or metabolic markers compared to resistance training alone.