Investigating the Association Between Serum 25‐Hydroxyvitamin D (25(OH)D) and Body Mass Index (BMI) With In Vitro Fertilization (IVF) Outcomes Among Iranian Women: A Case‐Control Study

Background and Aims: Infertility affects approximately 18.3% of couples in Iran, and in vitro fertilization (IVF) remains a widely used treatment. Vitamin D deficiency and elevated body mass index (BMI) have been linked to poorer reproductive outcomes in some populations, but region-specific evidence among Iranian women is limited. This study aimed to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] levels, BMI, and IVF outcomes in Iranian women. Methods: < 0.05. Results: = 0.04). Conclusion: Vitamin D deficiency and higher BMI are independently associated with increased risk of IVF failure among Iranian women. Optimizing vitamin D status and achieving a healthy BMI prior to IVF treatment may improve success rates. Given the observed association, routine assessment and supplementation of vitamin D in women of reproductive age preparing for assisted reproductive technologies should be considered. Future studies should adjust for additional potential confounders, including chronic inflammation and lifestyle factors.