Conclusions
Vitamin D supplementation in patients with PCOS resulted in an improvement in the levels of TT, hs-CRP, TAC, and MDA, but did not affect FT, DHEA-S, SHBG, FAI, NO, and GSH levels. Vitamin D co-supplementation, low-dose vitamin D supplementation (≤1,000 IU/day), and daily supplementation frequency appeared to be more conducive to improving hormones, inflammation, and oxidative stress in PCOS patients.