In a randomized control trial involving 90 insulin-resistant PCOS patients, high-dose vitamin D (4000 IU) had beneficial effects on total testosterone, sex hormone-binding globulin, free androgen index, serum hs-CRP, and plasma total antioxidant capacity levels compared with low-dose vitamin D (1000 IU) and placebo groups [41],[42]. This evidence concerns the gene SHBG and Insulin resistance.