The figure depicts the combined effects of Vitamin D, Testosterone and Insulin-like Growth Factor 1 (IGF-1) on mobility based on the current evidence of Clinical Trials. Each rectangle represents an anabolic hormone. The arrows in the opposite direction between the rectangles indicate the profound interrelationship of these 3 anabolic hormones. Each horizontal arrow describes the impact of a single anabolic hormone and the additive effects of multiple hormones on different objective measures of physical performance.
SPPB: Short Physical Performance Battery; ADL: Activities of Daily Living; PASE: Physical Activity Scale for the Elderly; LBM=lean Body Mass; 30 MWT: 30- minute- walking test; ASMM: appendicular skeletal muscle mass.