Vitamin D deficiency has an impact on the reproduction of more than 40% of reproductive age women globally. Fibroids are more common among African-American females owing to their decreased milk consumption and reduced absorption of ultraviolet rays, supporting the relation between vitamin D deficiency and fibroid development. Vitamin D has an inhibitory effect on leiomyoma cells by suppression of proliferation cell nuclear antigen (PCNA), BCL-2, BCL-w, CDK1, and catechol-O-methyltransferase (COMT) protein levels. A growing evidence support the relationship between vitamin D deficiency and endometriosis through overexpression of vitamin D recseptor (VDR) and α-hydroxylase enzyme, however, it is still unclear if the endometriosis patients could benefit from vitamin D supplementation. Effect of vitamin D supplementation on the metabolic outcomes of polycystic ovary (PCO) has been studied and reveled that it is negatively correlated with fasting glucose, fasting insulin, triglycerides, C-reactive protein, free androgen index, and Dehydroepiandrosterone (DHEAS) and positively associated with quantitative insulin sensitivity check index (QUICKI), high density lipoprotein cholesterol (HDL-C), and sexual hormone binding globulin (SHBG), whereas its impact on the ovarian function is still unclear. Vitamin D deficiency may worse the obstetrical outcomes, including preeclampsia, gestational diabetes, low birth weight, increased cesarean section rate, neonatal asthma, seizures, and preterm labor. The relationship between serum levels of 25-hydroxy-vitamin D (25(OH) D) and pregnancy rates in ART is still debatable, with the need to conduct more clinical trials toward it. The in vitro antiproliferative and prodifferentiative effect of vitamin D might find a role in control of hyperplastic overactive bladder. Several studies support that vitamin D deficiency constitutes a risk factor for development of many types of cancer such as breast, ovarian, and colorectal.
Part of the book: A Critical Evaluation of Vitamin D