##Amato MP, Derfuss T, Hemmer B, Liblau R, Montalban X, Soelberg Sørensen P, et al. Environmental modifiable risk factors for multiple sclerosis: Report from the 2016 ECTRIMS focused workshop. Mult Scler J. 2018; 24: 590–603. ##Sintzel MB, Rametta M, Reder AT. Vitamin D and multiple sclerosis: a comprehensive review. Neurol Ther. 2018; 7: 59–853####Nair R, Maseeh A. Vitamin D: The “sunshine” vitamin. J Pharmacol Pharmacother. 2012; 3: 118–26##Guner, S., Hagharı, S., Inanıcı, F., Alsancak, S., & Aytekın, G. Knee muscle strength in multiple sclerosis: relationship with gait characteristics. Journal of physical therapy science, 2015, 27(3), 809-813##Sangelaji, B., Kordi, M., Banihashemi, F., Nabavi, S. M., Khodadadeh, S., & Dastoorpoor, M. A combined exercise model for improving muscle strength, balance, walking distance, and motor agility in multiple sclerosis patients: A randomized clinical trial. Iranian journal of neurology, 2016, 15(3), 111##Garrett, M.,Hoga, N., Larkin,A., Saunders, J., Jakeman, P., Coot, S. Exercise in the community for people with minimal gait impair-ment due to MS: an assessor-blindrandomized controlled trial.Mult Scler.2013, 19 (6):782-7##Bahmani, E., Hoseini, R., & Amiri, E. Effect of Home-Based Aerobic Training and Vitamin D Supplementation on Fatigue and Quality of Life in Patients with Multiple Sclerosis During COVID-19 Outbreak, 2021##Williams, K. L., Low Choy, N. L., & Brauer, S. G. Center‐Based Group and Home‐Based Individual Exercise Programs Have Similar Impacts on Gait and Balance in People With Multiple Sclerosis: A Randomized Trial. PM&R, 2021, 13(1), 9-18##Asgari A, Haji N. Multiple sclerosis. Razi J Med Sci. 2006; 18(5):24-32##Kalron, A., Dolev, M., Greenberg-Abrahami, M., Menascu, S., Frid, L., Avrech-Shezifi, S., Achiron, A. Physical activity behavior in people with multiple sclerosis during the COVID-19 pandemic in Israel: Results of an online survey. Multiple sclerosis and related disorders, 2021, 47, 102603##Fleming, K. M., Coote, S. B., & Herring, M. P. An eight-week randomised controlled trial of home-based pilates for symptoms of anxiety, depression, and fatigue among people with MS with minimal-to-mild mobility disability: Study protocol. Mental Health and Physical Activity,2020, 19, 100341Michalczyk, M., Gołaś, A., Maszczyk, A., Kaczka, P., Zając, A. Influe##nce of Sunlight and Oral D3 Supplementation on Serum 25 (OH) D Concentration and Exercise Performance in Elite Soccer Players. Nutrients, 2020, 12(5), 1311##Haghighi, A, Nakhzari Khodakhir J, Hamedinia M, Nikkhah K. The effect of a combined aerobic exercise and coenzyme Q10 supplementation on some inflammatory factors and nerve growth in patients with multiple sclerosis, M.Sc. Thesis, Hakim Sabzevari University, 2019. [Persian] ##Enright, P. L., & Sherrill, D. L. Reference equations for the six-minute walk in healthy adults. American journal of respiratory and critical care medicine, 1998, 158(5), 1384-1387##Hemayattalab, R . "Measurement in Physical Education and Sports Science, Tehran, Science and Movement, Third Edition, 2013, 9S8H / 436 GV##Montgomery, P. S., & Gardner, A. W. The clinical utility of a six‐minute walk test in peripheral arterial occlusive disease patients. Journal of the American Geriatrics Society, 1998, 46(6), 706-711##Hayes, C. E., & Nashold, F. E. Vitamin D and multiple sclerosis. Vitamin D,2018, 989-1024##Wanner M, Richard A, Martin B, et al. Associations between objective and self-reported physical activity and vitamin D serum levels in the US population. Cancer Causes & Control 26: 881-891. (2015) ##Bauer, A., Lechner, I., Auer, M., Berger, T., Bsteh, G., Di Pauli, F., Deisenhammer, F. Influence of physical activity on serum vitamin D levels in people with multiple sclerosis. PloS one, 2020, 15(6), e0234333##Fukumoto S. Phosphate metabolism and vitamin D. Bonekey Rep. 2014; 3: 497##Farsi A, Shahidian Akbarp, Vaez Mousavi M, Jamshidi A. In a study investigating the effect of six weeks of Pilates exercises on balance using a biodex balance meter and muscle function in MS patients. Scientific Journal of Rehabilitation Medicine, 2016, 6 (3), 165-173##Balavi, A., & Ghanbarzade, M. Effect of Resistance Training with Different Intensities on Airway Resistance Indices and Fatigue and Muscular Endurance in Women with Multiple Sclerosis (MS). Thrita, 2020, 9(1) ##Kraemer WJ, Adams K, Cafarelli E, Dudley GA, Dooly C, Feigenbaum MS, et al. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Medicine and science in sports and exercise. 2002;34(2):364-80##Charette S, McEvoy L, Pyka G, Snow-Harter C, Guido D, Wiswell R, et al. Muscle hypertrophy response to resistance training in older women. J Applied Physiology. 1991;70(5):1912-6##Kargarfard, M., Shariat, A., Ingle, L., Cleland, J. A., & Kargarfard, M. Randomized controlled trial to examine the impact of aquatic exercise training on functional capacity, balance, and perceptions of fatigue in female patients with multiple sclerosis. Archives of physical medicine and rehabilitation, 2018, 99(2), 234-241##Medina-Perez C, de Souza-Teixeira F, Fernandez-Gonzalo R, de Paz Fernandez JA. Effects of a resistance training program and subsequent detraining on muscle strength and muscle power in multiple sclerosis patients. Neuro Rehabilitation. 2014;34(3):523-30##