In conclusion, non-obese age and weight matched PCOS women showed that 25(OH)D3 was associated with the fertilization rate, compared to controls; however, vitamin D metabolites were associated with embryology parameters and HOMA-IR, suggesting a possible relationship between differing vitamin D metabolites, oocyte maturation and insulin sensitivity in non-obese PCOS patients. Here, INS is linked to polycystic ovary syndrome.