Determination of Vitamin D Serum Levels in Patients Diagnosed With Multiple Sclerosis and Their Relationship With the Severity and Illness Behavior in the Metropolitan Hospital in Quito and Carlos Andrade Marín Hospital. Cambios rev. méd. 2016, 15 (1), 52-55. https://doi.org/10.36015/cambios.v15.n1.2016.199.