PLOD1 and polycystic ovary syndrome: The results of our study indicated that adding calcium and vitamin D supplements to metformin led to a superior effect on regulation of menstrual cycles in vitamin D-deficient/insufficient subjects with PCOS with no significant effects on serum levels of LH, FSH, LH to FSH ratio, IGF-1, IGFBP-1, or IGF-1 to IGFBP-1 ratio.