. Beyond its role in normal muscle function, vitamin D deficiency can interact with statins to produce myalgia-myositis, which can be reversed by normalizing serum vitamin D [7,13]. Exertional rhabdomyolysis may occur in diverse settings including marathons, ice skating, bicycling and swimming. Our hypothesis is that subjects with pre-existing low serum 25OHD are selected out for exertional rhabdomyolysis during strenuous activities.