Uzma Afreen, Mubushra Samina, Shaima Sultana Memon, Hafiz Syed Muhammad Osama Jafri, Sumaira Riffat, Saba Abrar. Relationship Between Serum 25-Hydroxy Vitamin D Level and Menstrual Cycle Irregularity: A Cross-Sectional Study. Pakistan Journal of Medical & Health Sciences 2023, 16, 511.