Hossain, Homayra Tahseen, Quazi Tarikul Islam, Md Abul Kashem Khandaker, and HAM Nazmul Ahasan. “Study of Serum Vitamin D Level in Different Socio-Demographic Population - A Pilot Study”. Journal of Medicine 19, no. 1 (December 7, 2017): 22–29. Accessed November 29, 2021. https://www.banglajol.info/index.php/JOM/article/view/34836.