According to research published in the August online issue of the Journal of Clinical Endocrinology and Metabolism, women (n=345) who were attempting to conceive via in vitro fertilization had significantly greater success rates of high quality embryo implantation and clinical pregnancy if vitamin D levels were 20ng/mL or more vs. those with levels less than 20ng/mL. In a subgroup analysis, the women with 25-hydroxy-vitamin D [25(OH)D] levels greater than 30 ng/mL had the highest chances of pregnancy. Authors suggested that low vitamin D levels may contribute to infertility and called for further studies.
Reference: Paffoni A, Ferrari S, Vigano P, et al. Vitamin D deficiency and infertility: Insights from in vitro fertilization cycles. The Journal of Clinical Endocrinology & Metabolism, 2014; jc.2014-1802 DOI: 10.1210/jc.2014-1802.