Ferdous, Sharmin, Farhat Hussain, Samira Hayee, Nahreen Akhtar, Suraiya Khanam, Khadiza Begum, and Adeba Sultana. “The Effect of the Maternal Vitamin D Level on the Risk of Spontaneous Pregnancy Loss in the First Trimester”. International Journal of Reproduction, Contraception, Obstetrics and Gynecology 10, no. 6 (May 27, 2021): 2215–2220. Accessed October 2, 2025. https://www.ijrcog.org/index.php/ijrcog/article/view/10188.