Eva, M. A.; Begum, N.; Kabir, A. A.; Ahmed, K. W.; Sharmin, M.; Saha, S. K.; Bayazid, M. B.; Hasan, S. A Study on Vitamin D Level Among the Patients Attending in a Private Chamber in Dhaka City. Northern Int. Med. Coll. J. 2020, 10, 393-396.