Vitamin D levels and prolonged menstrual cycle in women with polycystic ovary syndrome: a cross-sectional study (opens in new tab)

ObjectiveThis study evaluated serum vitamin D (VD) levels in women with polycystic ovary syndrome (PCOS) and assessed their association with menstrual cycle characteristics.MethodsIn this cross-sectional study, 449 women diagnosed with PCOS were stratified based on 25-hydroxyvitamin D [25(OH)D] levels: low VD group (<20 ng/mL) and normal VD group (≥20 ng/mL). Menstrual cycles of 26–35 days were defined as normal; cycles exceeding 35 days were classified as prolonged. All participants underwen...