Role of Vitamin D Supplementation Therapy on Ovulation and Insulin Resistance in Women with PCOS: A Randomized Controlled Trial

Introduction: Polycystic ovarian syndrome (PCOS) is the most prevalent worldwide female endocrine disorder, affecting nearly 5%-12% of reproductive-aged women. PCOS is the most common cause of anovulatory infertility and its foremost clinical symptoms include anovulation or oligo-ovulation, infertility, menstrual irregularity, polycystic ovaries and hyperandrogenism. PCOS is also common among infertile Arabian female population and it is associated with significant elevations in markers of metabolic syndrome, insulin resistance and cardiovascular risks. Unfortunately, PCOS is not a simple pathophysiologic process for which one treatment is sufficient to control all manifestations. Therefore, when choosing a treatment regimen, it should target specific manifestations and individualized patient goals.
Aim of the Work: The aim of this study is to assess the safety and the efficacy of vitamin D supplementation therapy on ovulation and metabolic changes in women with PCOS.
Study design: Prospective randomized controlled clinical trial.
Patients and Methods: The current study was conducted in the infertility clinics of Ain Shams University Maternity Hospital in the period between May 2015 and May 2017. It included 300 women diagnosed with polycystic ovary syndrome attending the infertility clinics of Ain Shams University Maternity Hospital.
Results: Being a classification criterion, 25OHD level was significantly lower in the vitamin D deficient subgroup compared to the normal vitamin D subgroup; whereas no significant differences were found between the vitamin D deficient group and the control group. In the same context, 25OHD level was statistically significantly lower in the control group compared to the normal vitamin D subgroup. Vitamin D deficient PCOS women tended to have higher degree of insulin resistance. Fasting glucose was statistically significantly higher in the vitamin D deficient subgroup compared to the normal vitamin D subgroup and the control group; and higher in the control group compared to the normal vitamin D subgroup. Fasting insulin level was statistically significantly higher in the vitamin D deficient subgroup and the control group compared to the normal vitamin D subgroup; whereas no statistically significant differences were found between the former two groups. HOMA2-IR was statistically significantly higher in the vitamin D deficient subgroup and the control group compared to the normal vitamin D subgroup; whereas no statistically significant differences were found between the vitamin D deficient subgroup and the control group. No statistically significant differences were found between the three groups in the various components of the lipid profile.
Conclusion: Results of the thesis showed that cumulative ovulation rate was significantly higher in the vitamin D deficient subgroup following vitamin D supplementation compared to the normal vitamin D subgroup and the control group with a rate ratio of 1.27 and 1.22, respectively. Number needed to treat was calculated to be 5.34 and 6.38 compared to normal vitamin D subgroup and control group respectively, i.e. 6.38 women are needed to be supplemented with vitamin D for one of them to benefit compared to control women. No significant differences were found between the three subgroups regarding the median ovulating dose of clomiphene citrate. Also, no significant differences in the cumulative clinical pregnancy rate between the ovulatory women of the three subgroups.