Synergistic Effects of Vitamin D Supplementation and Resistance Training on Insulin-Like Growth Factor 1 and Muscle Health: A Systematic Review.

Abstract

The interaction between vitamin D and insulin-like growth factor 1 in resistance-power training is not fully elucidated, despite their established roles in muscle physiology. Research compiles data about how resistance training and vitamin D supplementation affect the results of muscle parameters alongside serum insulin-like growth factor 1 concentrations. The research analysis utilized PRISMA guidelines. Seventeen studies were reviewed, including 11 randomized controlled trials and six observational studies. The included studies examined children, adults, the elderly, and patients with metabolic or hormonal disorders. The primary outcomes were serum insulin-like growth factor 1 and insulin-like growth factor-binding proteins, as well as muscle strength and physical function. Seventeen studies were included in the systematic review. Voluntary muscle expression of insulin-like growth factor 1 increased by at least 20%-30% in elderly women through resistance training ( P  < 0.01) though combined training increased muscle insulin-like growth factor 1 levels and functional capacity by 22% ( P  = 0.01). Data confirm a positive association between serum 25(OH)D and insulin-like growth factor 1 levels, while limited evidence suggests a moderate reduction in insulin-like growth factor-binding proteins. The combination and individual effects of vitamin D supplementation with resistance training systems enhance insulin-like growth factor 1 bioavailability and muscle health in vitamin D-deficient adults.