The aim of this study was to investigate the effects of a 6-week cycle of Nordic walking training intervention on the serum levels of vitamin D metabolites (25-OH-D3 and 1,25-OH-D3) and vitamin D receptors VDR, SIRT1, SIRT 3, and FOXO3a in patients with multiple myeloma. Here, FOXO3 is linked to plasma cell myeloma.