Vitamin D supplementation and its role in modulating ovarian reserve and oxidative stress in infertile females

Vitamin D deficiency is highly prevalent in Pakistan, among women, with 67–85 % of those diagnosed with polycystic ovarian syndrome (PCOS) having serum vitamin D levels below 20 ng/ml. Vitamin D deficiency is associated with impaired ovarian reserve and increased oxidative stress, both of which contribute to female infertility. This study aimed to compare the effectiveness of oral vitamin D supplementation versus a single intramuscular dose on ovarian reserve and oxidative stress markers in infertile women with low vitamin D levels. Methods This quasi-interventional study was conducted collaboratively by the Australian Concept Infertility Medical Centre and Aga Khan University, Karachi. Participants were divided into PCOS (Group A, n = 120) and non-PCOS (Group B, n = 60) groups. Vitamin D–deficient participants received a single intramuscular injection of vitamin D (200,000 IU), while vitamin D–insufficient participants received oral vitamin D (50,000 IU weekly). All participants were followed for 12 weeks. Statistical analysis was performed using Pearson’s chi-square test and paired t-test in SPSS version 22, with p < 0.05 considered statistically significant. Results Significant improvements in anti-Müllerian hormone (AMH), total antioxidant capacity (TAOC), and paraoxonase-1 (PON-1) levels were observed from baseline to post-treatment in vitamin D–insufficient PCOS and non-PCOS participants receiving oral supplementation (p < 0.01). Similarly, vitamin D–deficient participants who received intramuscular vitamin D showed highly significant increases in AMH, TAOC, and PON-1 levels (p < 0.001). Conclusions Intramuscular vitamin D administration effectively improves ovarian reserve and reduces oxidative stress in vitamin D–deficient infertile women. Oral vitamin D supplementation is beneficial for improving AMH, TAOC, and PON-1 levels in vitamin D–insufficient infertile women. Therefore, assessment of vitamin D status should be performed before initiating infertility treatment.